[Federal Register Volume 89, Number 245 (Friday, December 20, 2024)]
[Rules and Regulations]
[Pages 104318-104365]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-28707]
[[Page 104317]]
Vol. 89
Friday,
No. 245
December 20, 2024
Part II
Department of Transportation
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National Highway Traffic Safety Administration
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49 CFR Parts 561 and 571
Federal Motor Vehicle Safety Standards; FMVSS No. 305a Electric-Powered
Vehicles: Electric Powertrain Integrity Global Technical Regulation No.
20 Incorporation by Reference; Final Rule
Federal Register / Vol. 89 , No. 245 / Friday, December 20, 2024 /
Rules and Regulations
[[Page 104318]]
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DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety Administration
49 CFR Parts 561 and 571
[Docket No. NHTSA-2024-0091]
RIN 2127-AM43
Federal Motor Vehicle Safety Standards; FMVSS No. 305a Electric-
Powered Vehicles: Electric Powertrain Integrity Global Technical
Regulation No. 20 Incorporation by Reference
AGENCY: National Highway Traffic Safety Administration (NHTSA),
Department of Transportation (DOT).
ACTION: Final rule.
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SUMMARY: Consistent with a Global Technical Regulation on electric
vehicle safety, NHTSA is establishing Federal Motor Vehicle Safety
Standard (FMVSS) No. 305a to replace FMVSS No. 305, ``Electric-powered
vehicles: Electrolyte spillage and electrical shock protection.'' Among
other improvements, FMVSS No. 305a applies to light and heavy vehicles
and includes performance requirements for the propulsion battery. NHTSA
is also establishing a new regulation, part 561, ``Documentation for
Electric-powered Vehicles,'' that requires manufacturers to compile
risk mitigation documentation and to submit standardized emergency
response information to assist first and second responders handling
electric vehicles.
DATES:
Effective date: This final rule is effective February 18, 2025.
IBR date: The incorporation by reference of certain publications
listed in the rule is approved by the Director of the Federal Register
as of February 18, 2025.
Compliance dates: The compliance date is December 22, 2025, for the
emergency response documentation requirements. For all other
requirements, the compliance date is September 1, 2027, for vehicles
with a gross vehicle weight rating of 4,536 kilograms (kg) or less and
September 1, 2028, for vehicles with a gross vehicle weight rating over
4,536 kg. Small-volume manufacturers, final-stage manufacturers, and
alterers are provided an additional year to comply with the
requirements beyond the dates identified above. Optional early
compliance is permitted.
Petitions for Reconsideration: Petitions for reconsideration of
this final rule must be received no later than February 3, 2025.
ADDRESSES: Petitions for reconsideration of this final rule must refer
to the docket and notice number set forth above and be submitted to the
Administrator, National Highway Traffic Safety Administration, 1200 New
Jersey Avenue SE, West Building, Washington, DC 20590. All petitions
received will be posted without change to http://www.regulations.gov,
including any personal information provided.
Confidential Business Information: If you wish to submit any
information under a claim of confidentiality, you should submit your
complete submission, including the information you claim to be
confidential business information, to the Chief Counsel, NHTSA, at the
address given under FOR FURTHER INFORMATION CONTACT. In addition, you
should submit a copy, from which you have deleted the claimed
confidential business information, to Docket Management at the address
given above. When you send a submission containing information claimed
to be confidential business information, you should include a cover
letter setting forth the information specified in our confidential
business information regulation (49 CFR part 512). Please see further
information in the Regulatory Notices and Analyses section of this
preamble.
Privacy Act: The petition will be placed in the docket. Anyone is
able to search the electronic form of all submissions to any of our
dockets by the name of the individual submitting the submission (or
signing the comment, if submitted on behalf of an association,
business, labor union, etc.). You may review DOT's complete Privacy Act
Statement in the Federal Register published on April 11, 2000 (Volume
65, Number 70; Pages 19477-78) or you may visit https://www.transportation.gov/individuals/privacy/privacy-act-system-records-notices.
Docket: For access to the docket to read background documents or
comments received, go to https://www.regulations.gov at any time or to
1200 New Jersey Avenue SE, West Building, Room W12-140, Washington, DC
20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays. Telephone: (202) 366-9826.
FOR FURTHER INFORMATION CONTACT: For technical issues, you may contact
Ms. Lina Valivullah, Office of Crashworthiness Standards; Telephone:
(202) 366-8786; Email: [email protected]; Facsimile: (202) 493-
2739. For legal issues, you may contact Ms. K. Helena Sung, Office of
Chief Counsel; Telephone: (202) 366-2992; Email: [email protected];
Facsimile: (202) 366-3820. The mailing address of these officials is:
National Highway Traffic Safety Administration, 1200 New Jersey Avenue,
SE, Washington, DC 20590.
SUPPLEMENTARY INFORMATION:
Table of Contents
I. Executive Summary
II. Background
a. Overview of FMVSS No. 305
b. Overview of GTR No. 20
c. Statutory Authority
d. Overview of the Final Rule Requirements
e. Changes From the NPRM to the Final Rule
III. Summary of Comments
IV. Response to Comments on Proposed Requirements
a. Expanding Applicability of FMVSS No. 305a to Heavy Vehicles
1. Normal Vehicle Operations and Requirements for the REESS
2. Post-Crash Safety for Heavy School Buses
3. Post-Crash Safety for Other Heavy Vehicles
b. General Specifications Relating to Crash Testing
1. Low Energy Option for Capacitors
2. Assessing Fire or Explosion in Vehicle Post-Crash Test
3. Assessing Post-Crash Voltage Measurements
4. Electrolyte Leakage
c. Vehicle Controls for Safe REESS Operation
1. Vehicle- and Component-Level Testing
2. State of Charge (SOC)
3. Breakout Harness Location
4. Over-Temperature Test
5. Overcurrent Protection
6. Venting and Visual Inspection
d. Mitigating Risk of Thermal Propagation Due to Internal Short
Within a Single Cell in the REESS
e. Thermal Event Warning
f. Vehicle Control Malfunction Warning
g. Protection Against Water Exposure
h. Miscellaneous GTR No. 20 Provisions Not Proposed
1. Vibration and Thermal Shock and Cycling
2. Fire Resistance
3. Low State of Charge
i. Low-Speed Vehicles
j. Emergency Response Information
k. Documentation Requirements
l. Compliance Dates
V. Response to Comments on Issues Not Discussed in the NPRM
a. Future Battery Chemistries
b. Marking and Labeling
c. Test Laboratories
d. Other Electrical Specifications
e. Static Rollover
VI. Rulemaking Analyses and Notices
I. Executive Summary
NHTSA is issuing this final rule to achieve two goals. First, NHTSA
is establishing FMVSS No. 305a, ``Electric-powered Vehicles: Electric
Powertrain
[[Page 104319]]
Integrity,'' to upgrade and replace existing FMVSS No. 305. The new
FMVSS No. 305a has all the requirements of FMVSS No. 305 and expands
its applicability to vehicles with a gross vehicle weight rating (GVWR)
greater than 4,536 kilograms (kg) (10,000 pounds (lb)). FMVSS No. 305a
also adds requirements and test procedures covering new aspects of
electric vehicle safety, such as performance requirements for the
propulsion battery system, also referred to as the Rechargeable
Electrical Energy Storage System (REESS). NHTSA is also establishing a
new regulation, 49 CFR part 561 (part 561), ``Documentation for
Electric-powered Vehicles,'' to require that manufacturers submit, at
NHTSA's request, documentation addressing safety risk mitigation under
specified scenarios to demonstrate that they considered, assessed, and
mitigated risks for safe operation of the vehicle. Manufacturers are
also required to submit documentation to ensure both first \1\ and
second \2\ responders have access to vehicle-specific information about
extinguishing REESS fires and mitigating safety risks associated with
stranded energy \3\ when responding to emergencies. The restructured
and upgraded FMVSS No. 305a will facilitate future updates to the
standard as battery technologies and charging systems continue to
evolve.
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\1\ ``First responder'' means a person with specialized training
such as a law enforcement officer, paramedic, emergency medical
technician, and/or firefighter, who is typically one of the first to
arrive and provide assistance at the scene of an emergency.
\2\ ``Second responder'' means a worker who supports first
responders by cleaning up a site, towing vehicles, and/or returning
services after an event requiring first responders.
\3\ Stranded energy is the energy remaining inside the REESS
after a crash or other incident.
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The second goal is to further NHTSA's effort to harmonize the
Federal Motor Vehicle Safety Standards under the Economic Commission
for Europe 1998 Global Agreement (``1998 Agreement''). The efforts of
the U.S. and other contracting parties to the 1998 Agreement culminated
in the establishment of Global Technical Regulation (GTR) No. 20,
``Electric Vehicle Safety.'' \4\ FMVSS No. 305 already incorporates a
substantial portion of GTR No. 20's requirements due to a previous
NHTSA rulemaking. In 2017, NHTSA amended FMVSS No. 305 to include
electrical safety requirements from GTR No. 13, ``Hydrogen and fuel
cell vehicles,'' pertaining to electric vehicle performance during
normal vehicle operation and post-crash.\5\ Because GTR No. 13's
provisions for electric vehicles were later incorporated into what
would become GTR No. 20, the 2017 final rule that adopted GTR No. 13's
provisions adopted what later became many of the requirements of GTR
No. 20. That 2017 rulemaking, however, did not expand the applicability
of FMVSS No. 305 to include heavy vehicles nor did it include
requirements for the REESS. This final rule largely adopts these and
other GTR No. 20 requirements.
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\4\ GTR No. 20, https://unece.org/fileadmin/DAM/trans/main/wp29/wp29wgs/wp29gen/wp29registry/ECE-TRANS-180a20e.pdf.
\5\ GTR No. 13 only applied to light vehicles. Normal vehicle
operations include operating modes and conditions that can
reasonably be encountered during typical operation of the vehicle,
such as driving, parking, standing in traffic with the vehicle in
drive mode, and charging. Final rule, 82 FR 44950, September 27,
2017.
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The notice of proposed rulemaking (NPRM) preceding this final rule
was published on April 15, 2024. The comment period closed on June 14,
2024. After carefully reviewing the comments, NHTSA is adopting the
proposed requirements with some changes from the NPRM. Commenters to
the NPRM commented on the applicability to heavy vehicles; vehicle-
level testing; technical details on documentation requirements; test
procedures for evaluating fire risk mitigation; warning in the case of
a thermal event in the battery pack; and water exposure safety. NHTSA
addresses the comments in this final rule with minor changes to the
regulatory text. These changes include edits to definitions and test
procedures for clarity and accuracy, addition of a provision to exempt
out-of-reach rooftop charging systems from direct contact protection
requirements, and new regulation part 561 for documentation
requirements and emergency response information requirements.
High Level Summary of the Final Rule
FMVSS No. 305 currently only applies to passenger cars and to
multipurpose passenger vehicles, trucks, and buses with a GVWR of 4,536
kg (10,000 lb) or less (``light vehicles''). Consistent with GTR No.
20, FMVSS No. 305a expands the current applicability of FMVSS No. 305
to vehicles with a GVWR greater than 4,536 kg (10,000 lb) (``heavy
vehicles''). Under the final FMVSS No. 305a, light vehicles will be
subject to requirements carried over from FMVSS No. 305 that ensure the
safety of the electrical system during normal vehicle operations and
after a crash (post-crash). They will also be subject to new
requirements for the REESS. Heavy vehicles will be subject to the
requirements for electrical system safety during normal vehicle
operations and to requirements for the REESS. However, except for heavy
school buses, they will not be subject to post-crash requirements.
Heavy school buses (GVWRs greater than 4,536 kg (10,000 lb)) will be
subject to the requirements for electrical system safety during normal
vehicle operations and to the requirements for the REESS, and will have
to meet post-crash test requirements to ensure the vehicles protect
against unreasonable risk of electric shock and risk of fire after a
crash. The post-crash tests are the same tests described in FMVSS No.
301 for heavy school buses (impacted at any point and at any angle by a
moving contoured barrier).
The post-crash requirements of FMVSS No. 305a for light vehicles
and heavy school buses include electric shock protection (there are
four compliance options: low voltage, electrical isolation, protective
barrier, and low energy for capacitors); REESS retention; electrolyte
leakage; and fire safety. The requirements for REESS retention and
electrolyte leakage are already in FMVSS No. 305, but the final rule
adopts the NPRM proposal to enhance some provisions consistent with GTR
No. 20.
FMVSS No. 305a also includes new and comprehensive performance
requirements and risk mitigation strategies for safety of the REESS.
These REESS requirements will apply to all vehicles, regardless of
GVWR. A REESS provides electric energy for propulsion and may include
necessary ancillary systems for physical support, thermal management,
electronic controls, and casings. The requirements set a level of
protection of the REESS against external fault inputs, ensure the REESS
operations are within the manufacturer-specified functional range, and
increase the likelihood of safe operation of the REESS and other
electrical systems of the vehicle during and after water exposure
during normal vehicle operations.
The final rule addresses some aspects of REESS safety through
documentation measures, consistent with GTR No. 20. ``Documentation
measures'' means a list of information provided by manufacturers, at
NHTSA's request, that demonstrates that they considered, assessed, and
mitigated identified risks for safe operation of the vehicle. The final
rule's documentation requirements address: (a) safety risk mitigation
associated with charging and discharging during low temperature; (b)
providing a warning if there is a malfunction of vehicle controls that
manage REESS safe operation; (c)
[[Page 104320]]
providing a warning if there is a thermal event in the REESS; \6\ and
(d) safety risk mitigation for thermal runaway and propagation due to
an internal short circuit of a single cell. The GTR takes a
documentation approach to these aspects of safety because of the
rapidly evolving electric vehicle technologies and the variety of
available REESS and electric vehicle designs. NHTSA agrees that there
are currently no objective test procedures in these specified areas
that are not design restrictive given the current state of knowledge.
Thus, until test procedures and performance criteria can be developed
for all vehicle powertrain architectures, 49 CFR part 561 will require
manufacturers to submit documentation to NHTSA, at NHTSA's request,
that identifies all known safety hazards, describes their risk
mitigation strategies for the safety hazards, and, if applicable,
describes how they provide a warning to address a safety hazard. The
purpose of the documentation approach is two-fold. Given the variation
of battery design and design specific risk mitigation systems, the
documentation requirement will be a means of ensuring that each
manufacturer has identified safety risks and safety risk mitigation
strategies. The requirement provides a means for NHTSA to learn of the
risks associated with the REESS, understand how the manufacturer is
addressing the risks, and oversee those safety hazards. This approach
is battery technology neutral, not design restrictive, and is intended
to evolve over time as battery technologies continue to rapidly evolve.
It is an interim measure intended to ensure that manufacturers will
identify and address the safety risks of the REESS until such time as
objective performance standards can be developed that can be applied to
all applicable REESS designs.
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\6\ The NPRM proposed to include a thermal warning requirement
and a corresponding test procedure. After consideration of comments,
the final rule specifies an additional documentation requirement in
part 561 for the REESS thermal event warning instead of a
corresponding test procedure with the warning requirement.
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As part of NHTSA's battery initiative and in response to a 2020
NTSB recommendation,\7\ the NPRM proposed to include in FMVSS No. 305a
a requirement that vehicle manufacturers submit to NHTSA standardized
emergency response guides (ERGs) and rescue sheets for each vehicle
make, model, and model year. The uploaded ERGs and rescue sheets will
be publicly available on NHTSA's website for easy searchable access.
ERGs and rescue sheets communicate vehicle-specific information related
to fire, submersion, and towing, as well as the location of components
in the vehicle that may expose the vehicle occupants or rescue
personnel to risks, the nature of a specific function or danger, and
devices or measures which inhibit a dangerous state. The final rule
adopts the proposed requirement to submit standardized emergency
response information to a NHTSA website in part 561. The standardized
information will be available and understandable to first and second
responders so they can easily refer to vehicle-specific rescue
information en route to or at the scene of a crash or fire event and
respond to the emergency quickly and safely.
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\7\ ``Safety risks to emergency responders from lithium-ion
battery fires in electric vehicles,'' Safety Report NTSB/SR-20/01,
PB2020-101011, National Transportation Safety Board, https://www.ntsb.gov/safety/safety-studies/Documents/SR2001.pdf.
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NHTSA is issuing this final rule pursuant to and in accordance with
its authority under the National Traffic and Motor Vehicle Safety Act
(Safety Act). Under 49 United States Code (U.S.C.) Chapter 301, Motor
Vehicle Safety (49 U.S.C. 30101 et seq.), the Secretary of
Transportation is responsible for prescribing motor vehicle safety
standards that are practicable, meet the need for motor vehicle safety,
and are stated in objective terms. The Safety Act also authorizes NHTSA
to require manufacturers to retain certain records and/or make
information available to NHTSA. Section 30166 of the Act provides NHTSA
the ability to request and inspect manufacturer records that are
necessary to enforce the prescribed regulations. NHTSA is authorized by
delegation to issue regulations to carry out the agency's duties of
ensuring vehicle safety.\8\
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\8\ 49 U.S.C. 322(a); 49 CFR 1.95.
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NHTSA believes there are no notable costs associated with this
final rule. This final rule closely mirrors the electrical safety
provisions of GTR No. 20, which have been voluntarily implemented by
manufacturers in this country. The agency believes that the finalized
safety standards are widely implemented by manufacturers of light and
heavy electric vehicles and heavy electric school buses. Manufacturers
are also already providing emergency response information to the
National Fire Protection Association (NFPA); under part 561, they would
just have to standardize the format and submit the information to
NHTSA.
II. Background
a. Overview of FMVSS No. 305
The purpose of FMVSS No. 305, ``Electric-powered vehicles:
electrolyte spillage and electrical shock protection,'' is to reduce
deaths and injuries from electrical shock. The standard applies only to
light vehicles (vehicles with a GVWR less than or equal to 4,536 (kg)
(10,000 (lb)). The standard's requirements reduce the risk of harmful
electric shock: (a) during normal vehicle operation; and (b) in post-
crash situations to protect vehicle occupants, and rescue workers and
others who may come in contact with the vehicle after a crash. The
standard's requirements for the former protect against direct and
indirect contact of high voltage sources during everyday operation of
the vehicles. The focus of the ``in-use'' testing (unlike ``post-
crash'' testing) deals with performance criteria that will be assessed
without first exposing the vehicle to a crash test. The standard's
post-crash test requirements address electrical isolation following
frontal, rear, and side impacts of the vehicle, in addition to limiting
electrolyte spillage from propulsion batteries.
FMVSS No. 305 already has many of GTR No. 20's requirements for
light vehicles, including requirements for electrical safety during
normal vehicle operation; post-crash electrolyte spillage; post-crash
REESS retention; and most of the GTR's post-crash electrical safety
options for high voltage sources.
b. Overview of GTR No. 20
1. The GTR Process
The United States is a contracting party to the Agreement
concerning the Establishing of Global Technical Regulations for Wheeled
Vehicles, Equipment and Parts which can be fitted and/or be used on
Wheeled Vehicles (``1998 Agreement''). This agreement entered into
force in 2000 and is administered by the UN Economic Commission for
Europe's (UN ECE's) World Forum for the Harmonization of Vehicle
Regulations (WP.29). The purpose of this agreement is to establish
Global Technical Regulations (GTRs).
In March 2012, UNECE WP.29 formally adopted the proposal to
establish GTR No. 20 at its one-hundred-and-fifty-eighth session. NHTSA
chaired the development of GTR No. 20 and voted in favor of
establishing GTR No. 20.
As a Contracting Party Member to the 1998 Global Agreement that
voted in favor of GTR No. 20, NHTSA is obligated to initiate the
process used in the U.S. to adopt the GTR as an agency regulation. This
process was initiated by the NPRM published on April 15, 2024.
[[Page 104321]]
NHTSA is not obligated to adopt the GTR after initiating this process.
In deciding whether to adopt a GTR as an FMVSS, NHTSA follows the
requirements for NHTSA rulemaking, including the Administrative
Procedure Act, the National Traffic and Motor Vehicle Safety Act
(Vehicle Safety Act), Presidential Executive Orders, and DOT and NHTSA
policies, procedures, and regulations. Among other things, FMVSSs
issued under the Vehicle Safety Act ``shall be practicable, meet the
need for motor vehicle safety, and be stated in objective terms.''
2. GTR No. 20
GTR No. 20 establishes performance-oriented requirements that
reduce potential safety risks of electric vehicles while in use and
after a crash event. The GTR includes provisions that address
electrical shock associated with high voltage circuits of EVs and
potential hazards associated with lithium-ion batteries and/or other
REESS. One of the principles for developing GTR No. 20 was to address
unique safety risks posed by electric vehicles and their components to
ensure a safety level equivalent to conventional vehicles with internal
combustion engines.
The requirements in GTR No. 20, for Phase 1 in the GTR development
process, address issues relating to the safe operation of the REESS,
and the mitigation of fire risk and other safety risks associated with
the REESS. Phase 2 of the GTR No. 20 development process, which is
ongoing, will address issues involving long-term research and
verification.
GTR No. 20 applies to all electric-powered vehicles regardless of
GVWR, in contrast to FMVSS No. 305, which only applies to light
vehicles. FMVSS No. 305 currently includes the majority of GTR No. 20's
requirements regarding electric shock protection and applies these only
to light vehicles. GTR No. 20 also has safety requirements for the
REESS beyond those in FMVSS No. 305. A summary of these additional
requirements in GTR No. 20 for the REESS includes:
Safe operation of REESS under the following exposures during normal
vehicle operations:
REESS protection under external fault conditions and extreme
operating temperatures:
[cir] External short circuit
[cir] Overcharge
[cir] Over-discharge
[cir] Overcurrent
[cir] High operating temperature
[cir] Low operating temperature
Management of REESS emitted gases
Water exposure during vehicle washing and driving through 10-
centimeter (cm) deep water on roadway
Thermal shock and cycling (-40 [deg]C to 60 [deg]C)* \9\
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\9\ The asterisk notes that the NPRM did not propose to adopt
the GTR No. 20 requirement.
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Resistance to short duration external gasoline pool fire *
Vibration environment during normal vehicle operations *
Warning systems for REESS safe operation in case of:
Low energy content in REESS *
REESS control operational failure
Thermal runaway propagation due to single cell short circuit
in REESS
Thermal event in REESS
Installation (location) of REESS on the vehicle \10\
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\10\ This requirement is intended for countries with type
approval systems where a generic REESS can be approved separately
from the vehicle. A vehicle with a pre-approved REESS that complies
with the REESS installation requirement would not have to undergo
post-crash safety assessment for approval. This installation
requirement would not apply in the U.S. with a self-certification
system.
GTR No. 20 includes post-crash requirements but does not specify
the crash tests for post-crash evaluation. Instead, the GTR allows
contracting parties to apply the crash tests in their regulations.
Further, the GTR allows contracting parties to permit regulated
entities to comply with post-crash requirements without conducting
vehicle crash tests. In place of crash tests, a contracting party may
specify tests for ``mechanical integrity'' and ``mechanical shock'' of
the REESS.
The April 2024 NPRM \11\ proposed to complete the alignment of
FMVSS No. 305 with GTR No. 20 by proposing to establish FMVSS No. 305a,
which adopts all the requirements in FMVSS No. 305 and extends the
standard's electrical safety requirements to heavy vehicles. The NPRM
also proposed to adopt the above requirements under normal vehicle
operations for the REESS to light and heavy vehicles, except as noted
by an asterisk, because requirements for thermal shock and cycling,
resistance to short duration external pool fire, and vibration
environment are already included under United States Hazardous
Materials Regulations (HMR), 49 CFR parts 171 to 180, in accordance
with the international lithium battery transportation requirements of
UN 38.3, ``Transport of dangerous goods: Manual of tests and
criteria.'' The NPRM proposed adding the post-crash test requirements
in FMVSS No. 305 for light vehicles and adding a crash test for all
school buses similar to that in FMVSS No. 301, ``Fuel system
integrity.'' The NPRM also proposed a post-crash requirement for no
observed fire or explosion in the vehicle for a duration of one hour
after the crash test and a low energy post-crash option for capacitors
in the electric power train to meet electrical safety requirements.
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\11\ 89 FR 26704 (Apr. 15, 2024).
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c. Statutory Authority
NHTSA is issuing this final rule pursuant to and in accordance with
its authority under the National Traffic and Motor Vehicle Safety Act
(Safety Act). Under 49 United States Code (U.S.C.) Chapter 301, Motor
Vehicle Safety (49 U.S.C. 30101 et seq.), the Secretary of
Transportation is responsible for prescribing motor vehicle safety
standards that are practicable, meet the need for motor vehicle safety,
and are stated in objective terms (section 30111(a)). ``Motor vehicle
safety'' is defined in the Safety Act (section 30102(a)(8)) as ``the
performance of a motor vehicle or motor vehicle equipment in a way that
protects the public against unreasonable risk of accidents occurring
because of the design, construction, or performance of a motor vehicle,
and against unreasonable risk of death or injury in an accident, and
includes nonoperational safety of a motor vehicle.'' ``Motor vehicle
safety standard'' means a minimum standard for motor vehicle or motor
vehicle equipment performance (section 30102(a)(9)). When prescribing
such standards, the Secretary must consider all relevant available
motor vehicle safety information (section 30111(b)(1)). The Secretary
must also consider whether a proposed standard is reasonable,
practicable, and appropriate for the particular type of motor vehicle
or motor vehicle equipment for which it is prescribed (section
30111(b)(3)) and the extent to which the standard will further the
statutory purpose of reducing traffic accidents and associated deaths
and injuries (section 30111(b)(4)). The responsibility for promulgation
of FMVSSs is delegated to NHTSA (49 CFR 1.95).
The Safety Act also authorizes NHTSA to require manufacturers to
retain certain records and/or make information available to NHTSA.
Section 30166 of the Act provides NHTSA the ability to request and
inspect manufacturer records that are necessary to enforce the
prescribed regulations. NHTSA is also authorized by delegation to issue
regulations to
[[Page 104322]]
carry out the agency's duties of ensuring vehicle safety.\12\
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\12\ 49 U.S.C. 322(a). This provision states that the Secretary
of Transportation may prescribe regulations to carry out the duties
and powers of the Secretary. The authority to implement the Vehicle
Safety Act has been delegated to NHTSA.
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d. Overview of the Final Rule Requirements
Consistent with GTR No. 20, the new FMVSS No. 305a expands the
current applicability of FMVSS No. 305 to vehicles with a GVWR greater
than 4,536 kg (10,000 lb) (``heavy vehicles''). Under FMVSS No. 305a:
Light vehicles are subject to requirements carried over
from FMVSS No. 305 that ensure the safety of the electrical system
during normal vehicle operations and after a crash (post-crash).\13\
They are also subject to new requirements for the REESS.
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\13\ Current FMVSS No. 305 light vehicle post-crash test
requirements (front, side, and rear crashes) are aligned with FMVSS
No. 301's light vehicle post-crash test requirements.
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Heavy vehicles are subject to the requirements for
electrical system safety during normal vehicle operations and to
requirements for the REESS. However, except for heavy school buses,
they are not subject to post-crash requirements. This exclusion of
heavy vehicles, other than school buses, from crash tests, aligns with
similar exclusions in FMVSS No. 301, ``Fuel system integrity,'' for
conventional fuel vehicles and FMVSS No. 303, ``Fuel system integrity
of compressed natural gas vehicles,'' for compressed natural gas
vehicles.
Heavy school buses (GVWRs greater than 4,536 kg (10,000
lb)) \14\ are subject to the requirements for electrical system safety
during normal vehicle operations and to the requirements for the REESS,
and have to meet post-crash test requirements to ensure the vehicles
protect against unreasonable risk of electric shock and risk of fire
after a crash. The post-crash tests are the same tests described in
FMVSS No. 301 for heavy school buses (impacted at any point and at any
angle by a moving contoured barrier).
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\14\ In the school bus safety area, stakeholders, including
NHTSA, commonly refer to buses with a GVWR over 4,536 kg (10,000 lb)
as ``large'' school buses.
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The post-crash requirements of FMVSS No. 305a for light vehicles
and heavy school buses include electric shock protection (there are
four compliance options: low voltage, electrical isolation, protective
barrier, and low energy for capacitors); REESS retention; electrolyte
leakage; and fire safety. The requirements for REESS retention and
electrolyte leakage are in FMVSS No. 305, but FMVSS No. 305a enhances
some provisions consistent with GTR No. 20. For example, FMVSS No. 305
does not specify that there must be no fire or explosion after a crash
test. Electric vehicles may catch fire long after a collision or other
occurrence resulting in a fault condition. To account for the potential
delayed response, FMVSS No. 305a is prohibiting fire or explosion for a
one-hour post-test period.
A substantial portion of FMVSS No. 305a focuses on safety
provisions for the propulsion battery, the REESS. FMVSS No. 305a
includes comprehensive performance requirements for the REESS. These
REESS requirements apply to all vehicles, regardless of GVWR. A REESS
provides electric energy for propulsion and may include necessary
ancillary systems for physical support, thermal management, electronic
controls, and casings. The requirements set a level of protection of
the REESS against external fault inputs, ensure the REESS operations
are within the manufacturer-specified functional range, and increase
the likelihood of safe operation of the REESS and other electrical
systems of the vehicle during and after water exposure during normal
vehicle operations.
This final rule addresses some aspects of REESS safety through
documentation measures, consistent with GTR No. 20, through a new
regulation, part 561. ``Documentation measures'' means a list of
information provided by manufacturers, at NHTSA's request, that
demonstrates that they considered, assessed, and mitigated identified
risks for safe operation of the vehicle. These documentation
requirements address: (a) safety risk mitigation associated with
charging and discharging during low temperature; (b) providing a
warning if there is a malfunction of vehicle controls that manage REESS
safe operation; (c) providing a warning if there is a thermal event in
the REESS; and (d) safety risk mitigation for thermal runaway and
propagation due to an internal short circuit of a single cell. The GTR
takes a documentation approach to these aspects of safety because of
the rapidly evolving electric vehicle technologies and the variety of
available REESS and electric vehicle designs. The Informal Working
Group experts that drafted the GTR determined there currently are no
objective test procedures to evaluate safety risk mitigation designs or
the operations of warnings of a malfunction of vehicle controls in a
manner that is not design restrictive.
NHTSA agrees with this approach given the current state of
knowledge. Thus, until test procedures and performance criteria can be
developed for all vehicle powertrain architectures, manufacturers will
be required to submit documentation to NHTSA, at NHTSA's request, that
identifies all known safety hazards, describes risk mitigation
strategies for the safety hazards, and, if applicable, describes how
they provide a warning to address a safety hazard.\15\ The purpose of
the documentation approach is two-fold. Given the variation of battery
design and design specific risk mitigation systems, the documentation
requirement is a means of ensuring that each manufacturer has
identified safety risks and safety risk mitigation strategies. The
requirement provides a means for NHTSA to learn of the risks associated
with the REESS, understand how the manufacturer is addressing the
risks, and oversee those safety hazards. This approach is battery
technology neutral, not design restrictive, and is intended to evolve
over time as battery technologies continue to rapidly evolve. It is an
interim measure intended to ensure that manufacturers will identify and
address the safety risks of the REESS until such time as objective
performance standards can be developed that can be applied to all
applicable REESS designs. NHTSA will also acquire information from the
submissions to learn about the safety of the REESSs and potentially
develop the future performance standards for FMVSS No. 305a. The
documentation requirements are based on the approach of GTR No. 20, but
NHTSA focused the GTR's documentation requirements to enable the agency
to obtain more targeted information from manufacturers.
---------------------------------------------------------------------------
\15\ Section 30166 of the Vehicle Safety Act authorizes the
Secretary of Transportation (NHTSA by delegation) the ability to
request and inspect manufacturer records that are necessary to
enforce the prescribed regulations.
---------------------------------------------------------------------------
As part of NHTSA's battery initiative,\16\ this final rule also
establishes, through regulation, a requirement that vehicle
manufacturers submit to NHTSA emergency response guides (ERGs) and
rescue sheets for each vehicle make, model, and model year. The purpose
of the requirement is to provide information to first and second
responders regarding the safe handling of the vehicle in emergencies
and for towing and storing operations. The uploaded ERGs and rescue
sheets will be publicly available on NHTSA's website for easy
searchable access. ERGs and rescue sheets communicate vehicle-specific
information related to fire, submersion, and towing, as well as the
[[Page 104323]]
location of components in the vehicle that may expose the vehicle
occupants or rescue personnel to risks, the nature of a specific
function or danger, and devices or measures which inhibit a dangerous
state.
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\16\ https://www.nhtsa.gov/battery-safety-initiative.
---------------------------------------------------------------------------
NHTSA is requiring standardized formatting of the information. The
ERG and rescue sheet requirements include the layout and format
specified in ISO-17840, ``Road vehicles--Information for first and
second responders,'' which standardize color-coded sections in a
specific order to help first and second responders quickly identify
pertinent vehicle-specific rescue information. The standardized
information will be available and understandable to first and second
responders so they can easily refer to vehicle-specific rescue
information enroute to, or at the scene of, a crash or fire event and
respond to the emergency quickly and safely.
e. Changes From the NPRM to the Final Rule
In developing this final rule, NHTSA made some modifications to the
proposed regulatory requirements in response to comments received and
to improve clarity and accuracy of the regulatory text. In addition to
typographical corrections, the final rule differs from the April 2024
NPRM in the following ways:
1. Timing of voltage measurements for determining electrical
isolation post-crash. The proposal required voltage measurements for
assessment of post-crash electrical isolation to be made between 10 to
60 seconds from the time of impact. The final rule requires the voltage
measurements for post-crash electrical isolation assessment to be made
at least 10 seconds after impact. NHTSA determined that taking all the
voltage measurements for determining electrical isolation would
typically take more than 60 seconds and since electrical isolation
value is not expected to change with time, only specifying a minimum
time after impact for making the measurements is sufficient.
2. Definition of State of Charge (SOC). The definition of SOC was
updated to clarify that it is the available electric charge in a REESS
expressed as a percentage of its normal operating capacity specified by
the manufacturer and not as a percentage of the total charge (stored
energy) in the REESS.
3. Documentation requirements included in part 561. The NPRM
proposed documentation requirements in FMVSS No. 305a for manufacturers
to submit, upon request, documentation regarding vehicle and REESS
designs to mitigate the risk of vehicle fire and explosion resulting
from single cell thermal runaway in the REESS, loss or malfunction of
controls managing safe operation of the REESS, and vehicle operations
at low temperatures. The NPRM also proposed requiring manufacturers to
submit emergency response information to a repository prior to the
certification time of the vehicle. The final rule has moved these
requirements to part 561 because documentation requirements without
corresponding test procedures are better suited in a regulation.
Additionally, the final rule requires emergency response information to
be submitted to NHTSA's repository before first sale or lease of the
vehicle model upon the compliance date.
4. Thermal event warning documentation requirement. The NPRM
proposed a test procedure to evaluate the warning function resulting
from a thermal event in the REESS. Due to practicability and safety
concerns with the proposed test procedure, the final rule specifies an
additional documentation requirement in part 561 for the REESS thermal
event warning instead of a corresponding test procedure with the
warning requirement.
5. Maximum time to conduct driving through standing water test
(protection against water exposure). The NPRM proposed a maximum test
duration of 5 minutes for the driving through standing water test.
Based on NHTSA's recent testing, the final rule extends this time to 10
minutes because of the practicability concerns for conducting the test
within 5 minutes for water pools shorter than 500 meters.
7. Exclusion for rooftop charging systems. The final rule excludes
those high voltage devices on heavy vehicles not energized except
during charging of the REESS, that are installed out of reach on the
vehicle rooftop, from direct contact protection requirements. NHTSA
inadvertently excluded this carveout for the out of reach high voltage
devices from the proposed direct contact protection requirements.
8. Addition of loading specifications. The proposed crash test
procedure for heavy school buses inadvertently omitted the loading
specifications. Loading specifications matching FMVSS Nos. 301 and 303
have been added to the final regulatory text for completeness.
9. Compliance dates. The final rule adopts the proposed 1-year lead
time from the date of publication of the final rule to comply with the
emergency response information requirements. The proposed 2-year lead
time for complying with all other requirements for light vehicles is
largely adopted with a slight date change to align with the beginning
of the model year on or after the first September 1 that is at least
two years after the publication of the final rule. In response to
comments received, the final rule extends the heavy vehicles' lead time
to comply with the requirements other than the emergency response
information requirements to the first September 1 that is at least
three years after the publication of the final rule.
III. Summary of Comments
The NPRM preceding this final rule included requests for comment on
several topics, including the post-crash requirements, the thermal
event warning performance test, the water exposure tests, the exclusion
of some GTR No. 20 requirements, and the documentation requirements.
From April 15, 2024, to June 14, 2024, the agency received 38 comments
on the NPRM, including one that appears to be an accidental duplicate
submission. The comments were generally supportive of the proposed
rule, particularly with regard to the collection of standardized
emergency response information and harmonization with international
regulations. Many commenters suggested modifications to the proposed
requirements, including establishing documentation requirements in a
separate regulation instead of the FMVSS. Of the 37 unique comments,
the majority (26 comments) were submitted by vehicle and component
manufacturers and industry associations. Comments were also submitted
by standards testing laboratories (3 comments), a government agency (1
comment), and other stakeholders (7 comments).
The vehicle and component manufacturers that provided comments were
American Honda Motor Co. (``Honda''), Blue Bird Body Company (``Blue
Bird''), Bugatti Rimac d.o.o. (``Bugatti''), Daimler Truck North
America (``DTNA''), Eaton Corporation (``Eaton''), Ford Motor Company
(``Ford''), Freudenberg Battery Power Systems (``Freudenberg''),
Honeywell International (``Honeywell''), Hyundai America Technical
Center (``HATCI'' or ``Hyundai''), Lubrizol Corporation (``Lubrizol''),
Lucid Motors (``Lucid''), Navistar, New Flyer of America (``NFA''),
Nikola Corporation (``Nikola''), Nissan North America (``Nissan''),
Prevost, Rivian Automotive (``Rivian''), Tesla, and Volkswagen Group of
America (``Volkswagen'').
The industry associations that provided comments were the Alliance
for Automotive Innovation (``Auto Innovators''), Coalition for Safe
[[Page 104324]]
Autonomous Vehicles and Electrification (``SAVE Coalition''), Electric
Drive Transportation Association (``EDTA''), MEMA Vehicle Suppliers
Association (``MEMA''), National Electrical Manufacturers Association
(``NEMA''), Truck and Engine Manufacturers Association (``EMA''), and
Zero Emission Transportation Association (``ZETA''). Some manufacturers
that submitted comments individually indicated that they belong to one
of these industry associations and/or stated support for the comments
submitted by an industry association.
The standards testing laboratories and associations that provided
comments were UL Solutions, the American Council of Independent
Laboratories (``ACIL''), and the American Association for Laboratory
Accreditation (``A2LA'').
The National Transportation Safety Board (``NTSB'') submitted one
comment, expressing strong support for the proposed rulemaking.
The other stakeholders that provided comments were the Center for
Auto Safety (``CAS''), Consumer Reports, Creaform/Ametek
(``Creaform''), Electric Vehicle Rescue App (``EV Rescue App,'' two
comments), Michael Lillo, and Kurt Vollmacher.
With regard to heavy vehicles, the commenters generally expressed
support for the proposed requirements for heavy school buses. Comments
on applying additional requirements to other heavy vehicles were more
varied, with some commenters in favor of additional test requirements
at the component level or at the vehicle level, and others opposed. One
commenter requested that NHTSA add an exemption from the direct contact
protection requirements during normal vehicle operation for rooftop
charging systems on heavy vehicles.
With regard to post-crash safety, manufacturers expressed support
for the inclusion of the low energy option for capacitors. Commenters
also generally agreed with the proposed requirement that there be no
evidence of fire or explosion for the duration of one hour after each
crash test. Comments on the voltage measurement procedure were mixed,
with some commenters in agreement and others requesting changes to the
test specifications. Honda and Auto Innovators requested removal of the
60-second time limit for post-crash electrical isolation measurements,
which would align the specification with GTR No. 20. For electrolyte
leakage, commenters said that the updated terminology is appropriate,
but the 5-liter maximum leakage requirement is no longer relevant with
modern REESS chemistries.
With regard to the proposed requirements for safe operation of the
REESS, commenters commented about certain aspects of the proposed test
procedures, particularly the state of charge, breakout harness
location, and test termination specifications. Many comments from
industry disagreed with the agency's exclusion of component-level
compliance test options. For the thermal event warning, some commenters
also requested implementation of a documentation requirement instead of
a test requirement.
For the proposed documentation requirements, some commenters
requested clarification of the requirements and implementation in a
separate regulation. Most commenters expressed strong support for
NHTSA's proposed collection of standardized emergency response
information, with a few vehicle manufacturers requesting a modification
to the submission timeline. Some also requested extending the
compliance date for the other proposed requirements beyond 2 years
after publication of the final rule.
IV. Response to Comments on Proposed Requirements
a. Expanding Applicability of FMVSS No. 305a to Heavy Vehicles
1. Normal Vehicle Operations and Requirements for the REESS
Proposed Requirements
Consistent with GTR No. 20, the NPRM proposed to expand the current
applicability of FMVSS No. 305 to heavy vehicles. Under FMVSS No. 305a,
heavy vehicles (including heavy school buses) would have to meet the
same requirements as light vehicles for electrical system safety during
normal vehicle operations and for the REESS. The fundamentals for
protecting against an electrical shock are the same for light vehicles
and heavy vehicles. A failure of a high voltage system may cause
injurious electric shock to the human body.
Comments Received
Commenters generally expressed support for applying the expanded
electrical system safety requirements during normal vehicle operations
to heavy school buses. Comments on applying these requirements to other
heavy vehicles were more varied, with some commenters in favor of
additional test requirements at the component level or at the vehicle
level, and others opposed. MEMA agreed with the inclusion of heavy-duty
vehicles without crash testing. Auto Innovators commented that FMVSS
No. 305a should not apply to heavy vehicles at this time and more
research is needed. Auto Innovators noted that the proposed regulatory
requirements that were not previously applicable to heavy vehicles have
potential design implications that require thorough consideration by
the agency.
EMA disagreed specifically with application of the REESS
overcurrent test to heavy vehicles, which were exempted in GTR No. 20.
EMA said that NHTSA did not provide justification for applying the
overcurrent test requirement to heavy vehicles. EMA also requested that
NHTSA include an exemption from GTR No. 20 related to direct contact
protection during normal vehicle operation. Specifically, EMA stated
that the proposed requirement omitted an important exemption provision
for some heavy vehicle applications. Under this provision, conductive
connection devices not energized except during charging of the REESS
that are located on the roof of the vehicle and out of reach of a
person standing outside the vehicle are exempted from direct contact
protection requirements. EMA explained that this exemption is necessary
for rooftop pantograph charging systems used in some heavy vehicles
like transit buses.
Agency Response
The agency is adopting most of the requirements for heavy vehicles
as proposed in the NPRM, with one modification. Unlike the NPRM, the
final rule excludes direct contact protection requirements from those
high voltage devices on heavy vehicles not energized except during
charging of the REESS, that are installed out of reach on the vehicle
rooftop. NHTSA inadvertently excluded this carveout for high voltage
rooftop charging devices on heavy vehicles from the direct contact
protection provision in the proposed requirements for FMVSS No. 305a.
GTR No. 20 excludes high voltage sources that are not energized except
during charging of the REESS from direct contact protection
requirements if they are located on the vehicle rooftop such that the
wraparound distance from the instep of the vehicle, or the lowest step
(if multiple steps are present) of the vehicle, to the high voltage
source is at least 3 meters. NHTSA agrees that if the high voltage live
parts are not energized except during charging of the REESS and are out
of reach for a person standing outside of the vehicle, it is
appropriate to exempt those parts from the IPXXB direct contact
protection
[[Page 104325]]
requirement. NHTSA has included the relevant language in the regulatory
text of the final rule.
EMA also requested not applying the overcurrent test to heavy
vehicles. The overcurrent test in GTR No. 20 is applicable to light
vehicles that have the capability to be charged by an external DC
supply. GTR No. 20 states that the overcurrent test for heavy vehicles
will be considered in Phase 2, ``as it is unclear how to apply on
vehicles that have different charging technologies.'' GTR No. 20
specifies two methods of conducting the overcurrent test. In the first
method, the overcurrent is applied through the external DC supply
equipment connected to the vehicle inlet while the vehicle is charging
normally. In the second method, the charge current and the overcurrent
are applied through a breakout harness connected just outside the
REESS. The external DC supply equipment connected to the other end of
the breakout harness supplies the normal charge as well as the
overcurrent to the REESS. The overcurrent test procedure in FMVSS No.
305a uses the breakout harness method, so any challenges associated
with testing via the charging inlet for different charging technologies
are avoided. NHTSA evaluated the overcurrent test using the breakout
harness and found it to be an easy test to conduct that is practical
and feasible for different vehicle types.\17\
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\17\ Electric Vehicle GTR No. 20 Test Development, Validation,
and Assessment, DOT HS 812 092, April 2021, https://rosap.ntl.bts.gov/view/dot/55584.
---------------------------------------------------------------------------
Auto Innovators recommended excluding heavy vehicles from FMVSS No.
305a electrical system safety during normal vehicle operations and
REESS requirements at this time, citing the need for more research on
the implications of these requirements on heavy vehicle designs. Auto
Innovators did not provide additional information to support its
statement. NHTSA believes the requirements for normal vehicle
operations and the REESS in FMVSS No. 305a are basic safety measures
that should be included in all electric vehicle designs.\18\ These
basic safety measures ensure protection from electric shock and fire
originating in the electric powertrain and specifically in the REESS.
These measures include electrical isolation, direct and indirect
contact protection, protection of the REESS from abuse and external
inputs that could damage the REESS over time, and measures to ensure
the REESS always operates within its safe operating boundaries. The
agency believes that the requirements proposed in the NPRM for heavy
vehicles, including the overcurrent test requirement, are relevant and
appropriate for heavy vehicle safety and that the test procedures are
practicable.
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\18\ Lithium-ion Battery Safety Issues for Electric and Plug-in
Hybrid Vehicles, DOT HS 812 418, October 2017, https://www.nhtsa.gov/sites/nhtsa.gov/files/documents/12848-lithiumionsafetyhybrids_101217-v3-tag.pdf.
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2. Post-Crash Safety for Heavy School Buses
Proposed Requirements
In addition to the requirements for electrical system safety during
normal vehicle operations and for the REESS, the NPRM also proposed
requirements for post-crash safety of heavy electric school buses. The
NPRM proposed use of a moving contoured barrier test, where a barrier
traveling at any speed up to 48 km/h (30 mph) impacts the school bus at
any point and angle. The crash test requirement aligns FMVSS No. 305a
with the requirements for heavy school buses in FMVSS No. 301, ``Fuel
system integrity,'' and FMVSS No. 303, ``Fuel system integrity of
compressed natural gas vehicles.'' The agency did not propose a
provision in GTR No. 20 that allows the use of component-level
mechanical integrity and mechanical shock tests instead of vehicle
crash tests. NHTSA believes that post-crash safety is better evaluated
at the system level in a crash test.
Comments Received
Commenters were generally in favor of the proposed crash test
requirements for heavy school buses. Commenters NTSB, DTNA, Navistar,
and EV Rescue App expressed full support for the expanded requirements
for heavy school buses. In particular, NTSB agreed with expanding the
post-crash requirements and making full use of the system-level
requirements that exist for heavy school buses so the vehicles will be
subject to the full intent and scope of FMVSS No. 305a. Bus
manufacturers DTNA (Thomas Built Buses) and Navistar (IC Bus) also
agreed with the proposed crash test performance requirements, which are
consistent with FMVSS No. 301 and FMVSS No. 303. Navistar stated that
the proposed requirements for heavy school buses were reasonable and
would not add significant cost or weight to the vehicles. EMA noted
that the loading requirements should be added to the crash test
specifications in S10.2.3. Individual commenter Mr. Lillo also stated
general support for enhanced EV school bus safety and suggested
conducting time trials for bus evacuation.
One manufacturer disagreed with the proposed requirements for heavy
school buses. Blue Bird stated that including multiple post-crash
requirements makes FMVSS No. 305a more burdensome than the
corresponding requirements for non-electric school buses. Blue Bird
also said that the proposed rule would require manufacturers to crash a
school bus every time they make a change to the battery pack. Blue Bird
requested component-level testing instead of full-vehicle testing.
Agency Response
After reviewing the comments, NHTSA is adopting the crash test and
post-crash requirements for heavy school buses as proposed in the NPRM,
with the addition of loading specifications. EMA noted that the
proposed regulatory text in the NPRM did not state the school bus
loading condition for the crash test. This final rule corrects this
inadvertent omission; loading specifications matching FMVSS Nos. 301
and 303, as suggested by EMA, have been added to the regulatory text
for completeness. With regard to potential fire emergencies, in
addition to the requirements of this final rule, electric school buses
are subject to FMVSS No. 217, ``Bus emergency exits and window
retention and release,'' which specifies operating forces, opening
dimensions, and markings for emergency exits on school buses to
facilitate rapid evacuation, and FMVSS No. 302, ``Flammability of
interior materials,'' which specifies burn resistance requirements.
NHTSA will also continue to evaluate school bus safety, including
school bus evacuation, and update applicable safety standards as
technology changes over time.
Most commenters, including bus manufacturers, agreed with the
proposed requirements. The dissenting commenter expressed concerns over
the testing burden. With regard to the crash test requirements for
electric school buses, the dynamic moving contoured barrier test aligns
FMVSS No. 305a with FMVSS Nos. 301 and 303, which address post-crash
safety of heavy school buses using conventional fuel or compressed
natural gas. The four post-crash requirements for FMVSS No. 305a are
electric shock protection, REESS retention, electrolyte leakage, and
fire safety. These requirements do not necessitate multiple crash tests
and can be verified simultaneously. In other words, although there are
four post-crash requirements, only one crash test is needed. There are
also four compliance options for the electric shock protection
requirement to provide flexibility. With regard to repeated full-
[[Page 104326]]
vehicle crash testing for component modifications, the FMVSS specifies
the procedures that NHTSA uses to evaluate compliance. Manufacturers
may use other reasonable methods to certify the compliance of their
vehicles, such as simulations and component-level testing, which they
may find appropriate when making minor changes. The vehicles must meet
the FMVSS when tested by NHTSA according to the test procedures in the
standard. For these reasons, the agency is not persuaded by Blue Bird's
comments on the test burden of conducting full-vehicle crash tests for
school buses. NHTSA maintains that the requirements are reasonable and
appropriate for school bus safety and is adopting all proposed
requirements for heavy school buses from the NPRM.
3. Post-Crash Safety for Other Heavy Vehicles
Proposed Requirements
The NPRM did not propose crash testing requirements for heavy
vehicles other than heavy school buses because there is currently no
available test that would be appropriate for these vehicles. The NPRM
sought comment on applying a moving contoured barrier crash test to all
heavy electric vehicles while acknowledging the cost and practicability
constraints. The NPRM also sought comment on component-level tests that
are representative of actual impact loads in heavy vehicle crashes and
that can be applied to different weight classes of heavy vehicles.
GTR No. 20 provides an option for evaluating post-crash safety of
light vehicles using a mechanical integrity test (crush test) of the
REESS, with a quasi-static load up to 100 kN. GTR No. 20 also includes
a mechanical shock test that evaluates the REESS mountings and fixtures
by accelerating and decelerating the REESS installed on a sled system.
However, as noted in the NPRM, the loads and accelerations specified in
GTR No. 20 may be too low for heavy vehicles. In the absence of
additional data to develop appropriate requirements, the NPRM did not
propose component-level crash testing of heavy vehicle REESS.
Comments Received
Comments on the potential post-crash requirements for heavy
vehicles other than school buses were varied, with some commenters
suggesting vehicle-level or component-level tests and others stating
additional research is needed. NTSB commented that NHTSA should have
proposed the REESS mechanical integrity and mechanical shock test
requirements from GTR No. 20 for heavy vehicles, calling the exclusion
``unnecessary.'' NTSB noted that the component-level tests constitute
an established and applicable standard for heavy vehicle REESS that is
not design-restrictive. Alternatively, NTSB stated, FMVSS No. 305a
could at least include documentation requirements for post-crash safety
of the heavy vehicle REESS. MEMA and Eaton also stated support for the
inclusion of mechanical integrity and mechanical shock tests with
additional isolation criteria.
Heavy vehicle manufacturers, DTNA and Prevost, commented that
additional research should be conducted before establishing test
requirements for post-crash safety of heavy vehicle REESS. DTNA stated
support for the concept of the mechanical integrity test in general,
but said that further research is necessary to develop a repeatable,
reproducible, and practical test method. Prevost said additional
research is needed for mechanical shock testing because accelerations
on the REESS are highly design dependent. While Auto Innovators
disagreed with application of additional requirements to heavy vehicles
in general, Auto Innovators said it did not have significant concerns
about applying the mechanical shock test from GTR No. 20 to heavy
vehicles and suggested refining the test procedure by defining the
acceleration as a function of vehicle mass to provide a more granular
method.
Heavy vehicle manufacturer NFA agreed with NHTSA's assessment that
component-level tests are more appropriate than full scale crash tests
for heavy vehicles due to practicability, as did Navistar and EMA. None
of them provided data on crash loads for heavy vehicles; NFA expressly
stated that it does not have sufficient data to determine test
parameters at this time. NFA pointed to existing standards for
mechanical shock testing, stating that it currently uses the mechanical
shock requirements of UNECE R100, and noting industry standards for
compressed natural gas (CNG) vehicles require that the CNG storage
system can endure an inertial load of 8G, which is within the range of
the component test procedure from GTR No. 20.
Truck manufacturer Nikola stated that it designed and tested its
vehicles based on the moving barrier tests currently in FMVSS Nos. 208,
214, and 305, and recommended that NHTSA likewise use the moving
barrier for any heavy vehicle crash test requirements because it is
more representative of a passenger vehicle. For mechanical shock
testing, Nikola said that test facilities are not currently equipped
with a test apparatus capable of testing Nikola's entire REESS or
subset. Regarding mechanical integrity testing, Nikola disagreed with
establishing a requirement, as it is not required by GTR No. 20 and
Nikola already requires its battery pack manufacturers to follow the UL
2580 standard, which includes a crush test.
Tesla commented that component-level testing is inadequate for
mechanical integrity and mechanical shock testing, stating that the
test will not be representative of the full vehicle, especially if the
battery system must be removed from the vehicle for testing. Creaform,
a 3D measurement and analysis company, also recommended vehicle-level
post-crash requirements for heavy vehicles, saying that vehicle crashes
can impose higher loads on an unprotected REESS than quasi-static crush
tests, depending on the location of the REESS in the vehicle, and that
adjusting the component-level mechanical integrity and mechanical shock
test parameters would not cover the risks. Creaform said advanced
numerical simulations can serve as a lower-cost alternative to vehicle
crash testing. Battery manufacturer Freudenberg also disagreed with
component-level mechanical integrity testing, stating it will place
undue expectations on the battery enclosure. Freudenberg requested
alignment of FMVSS No. 305a with the UNECE regulation, which exempts
heavy vehicles from mechanical integrity test requirements.
Agency Response
In the absence of new data, the agency is not adopting post-crash
requirements for heavy vehicles other than heavy school buses in FMVSS
No. 305a. The agency did not propose post-crash requirements for heavy
vehicles other than school buses in the NPRM because additional
information is needed to develop requirements that are reasonable,
practicable, and appropriate for the vehicles. While NTSB stated that
the component-level tests in GTR No. 20 are appropriate, the comment
did not provide additional information. NTSB also suggested a
documentation requirement for post-crash safety, which was not
discussed in the NPRM and is therefore out of scope for this final
rule.
Comments from heavy vehicle manufacturers indicated that they
currently use industry standards such as UL 2580, ``Electric vehicle
battery testing and certification,'' and other safety regulations in
designing their vehicles and procuring battery packs. The industry
standards used by manufacturers are convenient tools to
[[Page 104327]]
establish best practices in design and generally lack the objectivity
needed for FMVSS. Further research will be needed to evaluate and
modify such testing standards for inclusion in the FMVSS. Further
investigation into heavy vehicle impacts and component-level test
specifications would also address commenters' concerns regarding
accurate representation of crash forces. As none of the comments
provided supporting data, the agency maintains that additional research
is necessary to determine appropriate post-crash requirements and
acceptability criteria for heavy vehicles other than heavy school buses
for future consideration of FMVSS adoption.
b. General Specifications Relating to Crash Testing
The NPRM proposed several general provisions from GTR No. 20 that
would apply to various testing and performance requirements. These
provisions pertain to light vehicles and heavy school buses subject to
the crash testing requirements of the proposed FMVSS No. 305a.
1. Low Energy Option for Capacitors
Proposed Requirements
Currently, FMVSS No. 305 S5.3 requires that vehicles meet one of
the following three criteria post-crash: electrical isolation; absence
of high voltage; or physical barrier protection. The NPRM proposed to
include a post-crash low energy option for capacitors in the electric
powertrain that is included in GTR No. 20. Capacitors store electrical
energy and may be connected directly to the chassis in some electric
power trains. In fuel cell electric vehicles (FCEVs), the high-voltage
systems may contain capacitors that are connected to high voltage buses
and are not electrically isolated. Such capacitors may be high voltage
sources post-crash (because a charged capacitor may not discharge
quickly) and may not be able to comply with post-crash electrical
safety requirements using the direct and indirect contact protection
option or the electrical isolation option. However, capacitors may not
pose a safety hazard when contacted, even though they may be high
voltage sources post-crash, because they are low energy high voltage
sources. NHTSA conducted an analysis of the potential hazard and
concluded that the post-crash electrical safety compliance option for
capacitors based on an electrical energy of 0.2 Joules or less provides
adequate safety from electrical shock and long-term harmful effects on
the human body.
Comments Received
Comments on the low energy option for capacitors were positive,
with manufacturers expressing support for the inclusion. Tesla agreed
that there is no need to fully discharge all the capacitors, and Auto
Innovators noted that the option is consistent with GTR No. 20 and
other applicable international regulations. Auto Innovators suggested
changing the y-capacitor calculation to match ECE 100.03,\19\ noting
that the proposed calculation ``is inconsistent with ECE practice where
the energy of a Y capacitor is the greater of 0.5Cy x
V11[supcaret]2 or 0.5Cy x V2[supcaret]2.'' Auto
Innovators also suggested a minor edit to the text of S8.2 to clarify
that the inclusion of the low energy specification for capacitors is an
additional option for the post-crash electrical safety requirement.
---------------------------------------------------------------------------
\19\ ECE R.100, ``Uniform provisions concerning the approval of
vehicles with regard to specific requirements for the electric power
train,'' https://unece.org/sites/default/files/2024-01/R0100r3e.pdf.
---------------------------------------------------------------------------
MEMA and Eaton commented that the low energy option for capacitors
in the powertrain should include additional isolation requirements.
MEMA said, ``criteria should include an isolation requirement from all
parts of battery system to the external power output connectors of the
battery pack as is currently included in FMVSS 305 S5.3, as well as
avoiding a single point of failure as a standard and best-practice.''
Eaton recommended the same criteria. MEMA and Eaton referred to these
two additional requirements as ``acceptability criteria,'' and
requested their inclusion in multiple sections.
Agency Response
In response to the comments, the final rule follows the proposal in
including a low energy option for capacitors for post-crash electrical
safety. However, as detailed below, the final rule adopts the GTR No.
20 method of calculating energy in y-capacitors. In addition, the first
paragraph of S8.2 has been edited for clarity and the typographical
errors in S8.2(a)(2) have been corrected as suggested by commenters.
Auto Innovators requested changing the y-capacitor energy
calculation to that in ECE R.100.03. We note that ECE R.100.03 does not
have the post-crash low energy optional method of meeting electric
safety requirements because ECE R.100.03 does not address post-crash
safety. The post-crash low energy option is available in ECE R.94,\20\
and the method of calculating capacitor energy post-crash is similar to
that in GTR No. 20. The NPRM proposed calculating the energy stored in
the two y-capacitors at once, assuming that each capacitance is the
same, and requiring that the total energy not exceed 0.2 Joules.
However, GTR No. 20 calculates the energy in each y-capacitor
separately, using the individual capacitance, and requires that the
energy in each capacitor does not exceed 0.2 Joules. Because the GTR
No. 20 method uses the actual capacitance of each y-capacitor in the
corresponding calculation, and therefore more accurately represents the
stored energy in each, NHTSA is adopting the method from GTR No. 20 and
requiring that the energy in each capacitor not exceed 0.2 Joules.
---------------------------------------------------------------------------
\20\ ECE R.94 Revision 4, ``Concerning the Adoption of
Harmonized Technical United Nations Regulations for Wheeled
Vehicles, Equipment and Parts which can be Fitted and/or be Used on
Wheeled Vehicles and the Conditions for Reciprocal Recognition of
Approvals Granted on the Basis of these United Nations
Regulations,'' https://unece.org/sites/default/files/2024-07/R094r4e.pdf.
---------------------------------------------------------------------------
FMVSS No. 305a includes provisions for electrical isolation. As
proposed, the post-crash electrical safety requirements in FMVSS No.
305a are the same as the current requirements in FMVSS No. 305, except
for the addition of a low energy option for capacitors to comply with
electrical safety requirements. All high voltage sources, including the
REESS, need to be either electrically isolated, contactors open
resulting in low voltage, or have direct and indirect contact
protection. The low energy option for capacitors does not circumvent
the requirements for electrical protection, but rather allows for
another verification method.
The requirement to ensure no single point of failure (e.g., contact
failure) was not discussed in the NPRM and is not in scope of this
rulemaking. The FMVSS requirements are written in a manner to not be
design restrictive, and therefore do not prescribe a particular
connection to the battery due to the variation of battery designs.
However, the requirements for the REESS that are included in FMVSS No.
305a for normal vehicle operations and post-crash scenarios verify that
the system design provides a requisite level of safety. Comprehensive
risk mitigation of potential hazards is further addressed by the
documentation requirements. As discussed later in Section IV.n.,
``Documentation Requirements,'' manufacturers are required to
demonstrate that they have considered and addressed identified safety
risks for their vehicles. Designing separate connections to the battery
and avoiding a single point of failure are examples of risk mitigation
strategies that could be implemented by manufacturers along
[[Page 104328]]
with other protective measures. Additional requirements for the post-
crash low energy option for capacitors, beyond those test and
documentation requirements discussed above, were not included in the
NPRM and so are not in scope for this final rule. NHTSA will continue
to study and discuss further requirements for battery safety, including
additional requirements for post-crash low energy option for
capacitors, during the ongoing efforts on Phase 2 updates to GTR No.
20. Harmonization with the GTR No. 20 Phase 2 updates would be
considered in future updates to the FMVSS No. 305a requirements.
2. Assessing Fire or Explosion in Vehicle Post-Crash Test
Proposed Requirements
In accordance with GTR No. 20, NHTSA proposed to include in FMVSS
No. 305a a requirement that there be no evidence of fire or explosion
for the duration of one hour after the crash test for heavy school
buses, and for the duration of one hour after each crash test and
subsequent quasi-static rollover test for light vehicles. The
assessment of fire or explosion would be verified by inspection without
removal of the REESS or any parts of the vehicle.
Comments Received
Commenters generally agreed with the proposed requirement. MEMA,
Auto Innovators, Lucid, and Nikola stated support, with Nikola saying
that the provision should also apply to heavy vehicles if a crash test
requirement is added. Tesla agreed with the proposal as well but
requested additional guidance and an explicit evaluation procedure. In
contrast to other industry members, SAVE Coalition disagreed with
implementing the requirement at the vehicle level because FMVSS Nos.
208, 214, 301, and 303 do not include the same requirement for other
types of vehicles. SAVE Coalition said, ``If NHTSA's intent is to
regulate fire risks from all vehicle systems, that requirement should
be applied more generally in a regulation covering all vehicles
regardless of powertrain. For the purposes of assessing electric
vehicle safety, and to align with GTR 20 and the stated intent in the
preamble, this requirement should be clarified to be specific to REESS
related fires.''
Agency Response
After considering the comments, NHTSA has decided to adopt the
proposed post-crash requirement that there be no evidence of fire or
explosion. For electric vehicles, thermal runaway and propagation poses
a significant fire risk regardless of electrolyte leakage from the
battery pack, so FMVSS No. 305a addresses fire safety assessment
directly. The post-crash assessment does not require disassembly of the
vehicle or components. Evidence of fire or explosion could include
flames, smoke, scorch marks, or other indications. If such evidence
were visible at any time within the one-hour inspection period
following the crash test, the vehicle would fail to meet the safety
requirement. The agency maintains that the requirement is appropriate
as written.
Regarding SAVE Coalition's concern that only electric vehicles, not
other vehicle types, are subject to post-crash fire assessment, NHTSA
would like to explain the FMVSS safety requirements that were cited.
FMVSS No. 208, ``Occupant crash protection,'' and FMVSS No. 214, ``Side
impact protection,'' apply to vehicles regardless of fuel type and
address the physical forces and accelerations in a crash; electric and
non-electric vehicles must meet the safety requirements in these
FMVSSs. Fire resulting from spillage or leakage of combustible fuels is
addressed in fuel specific FMVSSs, including FMVSS No. 301, ``Fuel
system integrity,'' and FMVSS No. 303, ``Fuel system integrity of
compressed natural gas vehicles,'' by limiting combustible fuel
spillage or leakage. For electric vehicles, FMVSS No. 305a addresses
fire safety assessment directly because limiting electrolyte leakage
outside of the battery pack is insufficient to address the risk of fire
from thermal runaway and propagation in the REESS. Further, it may be
difficult to ascertain the origin of a fire observed at the vehicle
level, and exempting fires that may originate in or involve other
vehicle systems would not be beneficial to safety. For these reasons,
the agency is adopting the proposed requirement.
3. Assessing Post-Crash Voltage Measurements
Proposed Requirements
The NPRM proposed that the post-crash voltage measurements in FMVSS
No. 305a would be made between 10 seconds and 60 seconds after impact.
Using the time of impact to define the measurement period avoids a
source of ambiguity present in FMVSS No. 305 and is consistent with the
GTR No. 20 test procedure. The voltage measurement and calculation
methods in the NPRM are otherwise the same as those currently in FMVSS
No. 305.
Comments Received
Comments on the voltage measurement procedure were mixed, with some
commenters in agreement and others requesting changes to the test
specifications. Manufacturers Nikola, Tesla, and Lucid agreed with the
agency's rationale and stated support for the proposed requirements.
However, Honda said that the timing language is ambiguous and ``could
be misinterpreted to mean that the requirements must be met both at 10
seconds and 60 seconds after the impact.'' Honda also said that 60
seconds is insufficient for isolation resistance measurements and
requested full alignment with GTR No. 20, which does not include the
upper time limit for electrical isolation. Auto Innovators provided a
similar comment, noting that electrical isolation is stable and
requesting removal of the 60-second limit for post-crash isolation
measurements.
Auto Innovators commented on the proposed calculation method as
well, stating, ``the NPRM assumes that V1+V2=Vbat, but this may not be
strictly true,'' due to multimeter resistance. Auto Innovators provided
revised diagrams and formulas and suggested that FMVSS No. 305a provide
an electrical isolation compliance option matching ECE 100.03. Bugatti
also disagreed with the calculation method for the electrical isolation
baseline measurement, saying that it does not address a potential zero-
volt measurement across Ro that may occur if Ri is much higher. Bugatti
noted that the proposed requirements do not allow the use of a
megohmmeter as an alternative method to avoid the zero-volt issue.
Bugatti requested clarification and recommended adding the megohmmeter
measurement method allowed by ECE 100.03. As with the low energy option
for capacitors, Eaton again suggested adding acceptability criteria for
battery isolation.
Agency Response
The agency is adopting the proposed requirements with a minor
revision for the timing of voltage measurements for assessing
electrical isolation post-crash. The proposed requirements stated that
the post-crash voltage measurements would be made ``between 10 to 60
seconds after impact.'' The agency believes that this language is clear
but agrees that the time specification should distinguish between
compliance options. The post-crash electrical safety requirements
include four compliance options: low voltage, electrical isolation,
protective barrier, and low energy for
[[Page 104329]]
capacitors. After further consideration, the agency agrees that the 60-
second time limit is unnecessary for the electrical isolation
measurement procedure because the values are static and that
harmonization with the GTR No. 20 specification is appropriate. For
these reasons, the post-crash test specification has been modified to
state that the measurements for the electrical isolation compliance
option are made at least 10 seconds after impact, with no upper time
limit.
With regard to possible zero-volt measurements in the electrical
isolation baseline calculation, the agency does not believe there is an
issue. Consistent with GTR No. 20, the minimum resistance of the
voltmeter is specified, and a higher resistance R0 can be used if the
voltage measurement is very low. The agency has not observed zero-volt
measurements in testing using the specified procedures, which were
evaluated for practicability and repeatability. The megohmmeter option
from UNECE R100 is not incorporated because research has shown that the
megohmmeter method may provide different results than the multimeter
method. The agency believes inclusion of the megohmmeter option could
lead to inconsistent results and would not be beneficial.
Auto Innovators provided an alternate measurement method and
calculations for electrical isolation resistance that takes into
consideration the resistance of the multimeter used for voltage
measurements. Auto Innovators noted that this alternate method is in
ECE R.100.03 and requested harmonizing with ECE R.100.03. However, the
test method and calculations in ECE R.100.03 \21\ are the same as those
currently in FMVSS No. 305 and proposed in the NPRM for FMVSS No. 305a.
Regardless, the agency will continue evaluating the recommended
alternate procedure to determine whether the results and ease of
testing support its inclusion in FMVSS No. 305a. The alternate method
was not proposed in the NPRM and is therefore out of scope of this
rulemaking. If the agency's research supports use of the alternate
measurement procedure and calculations, they may be added at a later
date. At this time, NHTSA is adopting the method currently in FMVSS No.
305 and proposed in the NPRM for inclusion in FMVSS No. 305a.
---------------------------------------------------------------------------
\21\ See Annex 5A on page 40 in ECE R.100.03 at https://unece.org/sites/default/files/2024-01/R0100r3e.pdf.
---------------------------------------------------------------------------
The suggestion to add acceptability criteria for battery isolation
to the post-crash requirements was discussed earlier in Section IV.b.1,
``Low Energy Option for Capacitors.''
4. Electrolyte Leakage
Proposed Requirements
The NPRM proposed to include a post-crash requirement limiting
electrolyte leakage; this requirement is currently in FMVSS No. 305 as
``electrolyte spillage'' and permits no more than 5 liters of
electrolyte spilled or leaked. NHTSA sought comment on the necessity
and relevance of such a requirement for current EVs, as well as
recommendations regarding electrolyte leakage detection methods and
differentiation from other liquids.
Comments Received
Commenters agreed that the updated terminology of ``electrolyte
leakage'' is appropriate but stated that the 5-liter maximum leakage
requirement is no longer relevant. Auto Innovators and Nikola both said
that leakage outside of the battery pack should not occur with modern
EVs and that 5 liters is a very large amount. Auto Innovators stated
that there is no reliable method to detect or quantify leakage and
recommended that the requirement be removed entirely. Tesla stated that
physical characteristics can be used to determine whether electrolyte
or coolant has leaked from the vehicle if differentiation is a concern.
Nikola suggested that any electrolyte leakage outside of the battery
pack should constitute a failure. Blue Bird noted that there are many
different forms of electrolytes, including solids and gels, and leakage
may not be observed.
Agency Response
This final rule adopts the updated ``electrolyte leakage''
terminology and the current FMVSS No. 305 requirement for no more than
5 liters of electrolyte leakage post-crash. The cells of lithium-ion
batteries in current EVs have small quantities of electrolyte that
could leak out of the battery casing rather than spill. The agency
agrees with commenters that any electrolyte leakage in EVs using
lithium-ion batteries would be significantly lower than the current 5-
liter limit in FMVSS No. 305. However, there are other types of
batteries with aqueous electrolyte that may be considered for vehicle
applications in the future.\22\ At this time, it is unclear whether the
5-liter limit will remain appropriate for future batteries.
Specifically for vehicles using a REESS with aqueous electrolyte, GTR
No. 20 similarly includes a requirement limiting electrolyte leakage to
no more than 5 liters within 60 minutes after the crash test.\23\
Because there is no further information available, the agency is
adopting the post-crash electrolyte leakage limit of 5 liters that is
consistent with the current requirements in FMVSS No. 305 and GTR No.
20. However, unlike GTR No. 20, the agency is not distinguishing
between REESS with different types of electrolyte; the requirements in
FMVSS No. 305a are established as battery chemistry-neutral and are
applicable to all types of REESS. The agency will continue to review
and update the requirements in FMVSS No. 305a over time, as relevant
information becomes available.
---------------------------------------------------------------------------
\22\ Sodium ion aqueous batteries (SIAB), which are
environmentally benign, provide a promising alternative for safe,
cost-effective, and scalable energy storage, with high power
density. However, current SIABs have limited output voltage and
inadequate energy density for vehicle applications.
\23\ GTR No. 20 also requires that no more than 7 percent by
volume of the REESS electrolyte shall leak into the passenger
compartment. However, as noted in the NPRM, there is no practical
way of measuring the quantity by volume of the electrolyte in the
REESS to ensure compliance with such a requirement.
---------------------------------------------------------------------------
While one commenter suggested a requirement for no electrolyte
leakage outside of the battery pack, a post-crash requirement
prohibiting any electrolyte leakage from the pack was not proposed in
the NPRM and is out of scope for this final rule. A post-crash test
requirement prohibiting any amount of leakage outside of the battery
pack may also be challenging to verify. However, as in FMVSS No. 305,
this final rule includes a requirement that no visible trace of
electrolyte shall leak into the passenger compartment of the vehicle
for occupant safety. This final rule also adopts visual inspection
requirements in the tests evaluating safety during normal vehicle
operations, including no evidence of electrolyte leakage or venting
(without disassembly of the vehicle), as discussed in Section IV.c.6.,
below.
c. Vehicle Controls for Safe REESS Operation
Overview
The NPRM proposed requirements and associated full-vehicle tests
for vehicles to ensure they have controls managing safe REESS
operation, specifically overcharge, over-discharge, overcurrent, over-
temperature, and external short-circuit protection. These requirements
are applicable to light vehicles and heavy vehicles, and are generally
aligned with those in GTR No. 20, with minor differences for ease of
testing. The NPRM also proposed documentation requirements for low-
temperature protection, as in GTR No.
[[Page 104330]]
20, because no practical test procedure currently exists.
Commenters addressed a variety of topics related to the
requirements for safe REESS operation. The comments submitted by NTSB
and Consumer Reports expressed appreciation and support for the
requirements to ensure REESS safety and longevity. The comments from
industry also expressed general agreement with the requirements for
safe REESS operation but disagreed about certain aspects of the test
procedures. Specifically, these comments addressed vehicle- and
component-level testing, REESS state of charge, breakout harness
location, over-temperature testing, overcurrent protection, and venting
and visual inspection, as detailed below. Overall vehicle- and
component-level testing is addressed below in section IV.c.1. Comments
on specific testing provisions for vehicle controls are then addressed
in sections IV.c.2 through c.6.
1. Vehicle- and Component-Level Testing
Proposed Requirements
The NPRM proposed vehicle-level testing using a breakout harness
connected to a battery tester/cycler to evaluate vehicle controls for
safe REESS operation. The test procedures ensure the vehicle controls
provide protection against overcharge, over-discharge, overcurrent,
over-temperature, and external short-circuit fault conditions.
Maintaining the REESS within the manufacturer-specified functional
range minimizes the risk of fire and electrical shock. NHTSA proposed
vehicle-level testing of the REESS because testing at the equipment
level would not evaluate all relevant vehicle controls or any
interaction or interference between vehicle controls.
Comments Received
Many comments from industry disagreed with the agency's exclusion
of component-level compliance test options, which are included in GTR
No. 20 and ECE R100.03. Auto Innovators, Bugatti, EMA, Ford, Honda,
Hyundai, Lucid, NFA, Nissan, UL Solutions, and ZETA were among those
that requested component-level testing. ZETA stated that manufacturers
``could face hurdles in transitioning to vehicle-level testing,
including changing logistics, higher costs, and lack of testing
equipment availability.'' Auto Innovators likewise said that vehicle-
level testing would add significant cost without increasing robustness
or stringency.
Ford agreed with Auto Innovators, saying that it does not have
large enough facilities, and noted that NHTSA did not provide data
showing a need for full-vehicle testing. Honda stated that vehicle-
level testing requires specialized parts, increases safety risks, and
reduces control over test conditions compared to component-level
testing. NFA said requiring full-vehicle testing would be burdensome
and redundant, because the same pack would be tested multiple times.
Hyundai said that the option to conduct testing at the component level
would enable manufacturers to iterate on REESS design and safety
systems more rapidly. Lucid said, ``testing at the component level
(REESS) provides the benefit of recreating the worst-case scenario,
ideal for safety testing, due to its smaller thermal mass. Vehicle-
level testing would also require larger thermal shock chambers than
currently used at the REESS-level.'' UL Solutions also suggested adding
UL 2580 certification as another compliance option, while ZETA further
requested that NHTSA allow manufacturers to specify their own boundary
conditions for component-level testing because each vehicle model is
different.
A few commenters suggested that component-level testing should be
allowed under certain conditions or for specific tests. Nissan
suggested that NHTSA allow a component-level compliance option if the
manufacturer can demonstrate that the test results reasonably reflect
the safety performance of the complete REESS under the same conditions.
UL Solutions similarly requested that the agency ``allow independent
testing of the battery if the battery can demonstrate compliance to the
requirements without the benefit of the vehicle support systems.''
Tesla agreed with most of the proposed test procedures but requested a
component-level compliance option for the over-temperature test, as
``it would be difficult to characterize real-world driving temperature
profiles fully and accurately due to variable drive states.'' Nikola
stated that vehicle-level testing for overcharge, over-discharge, and
over-temperature protection cannot be conducted on hybrid or fuel cell
EVs, so those tests should be conducted at the component level.
Agency Response
After reviewing the comments, the agency is adopting the
requirements as proposed because vehicle-level testing is supported by
NHTSA's research for its practicability and feasibility. NHTSA-funded
research independently evaluated, refined, and validated the proposed
vehicle-level test procedures for various types of electric vehicles
(HEV, PHEV, and BEV).\24\ NHTSA conducted additional research to
evaluate capabilities in compliance test laboratories and
practicability of vehicle level tests.\25\ The test program
demonstrated the ease of conducting tests at the vehicle level using
breakout harnesses connected to a battery cycler/tester for the
external inputs to the REESS without having to remove the REESS from
the vehicle to conduct component-level tests. Evaluating REESS
operation at the vehicle level is consistent with other FMVSSs and
ensures the entire system is captured, including input from different
subsystems and any interaction or interference between vehicle
controls, and is most representative of real-world conditions. A
vehicle level test also ensures that the boundary conditions are
appropriate and would not be challenged in the event of a compliance
test failure. NHTSA's initial research for test procedure development
for electric vehicles was done with the whole vehicle and not with
individual components in the vehicle.\26\ The comments did not
demonstrate that component-level testing of the REESS would provide the
same comprehensive evaluation, nor that full-vehicle tests cannot be
conducted on all applicable vehicles.
---------------------------------------------------------------------------
\24\ System-Level RESS Safety and Protection Test Procedure
Development, Validation, and Assessment-Final Report,'' DOT HS 812
782, https://rosap.ntl.bts.gov/view/dot/42551.
\25\ Test reports and laboratory test procedures are available
in the docket NHTSA-2021-0029. https://www.regulations.gov/docket/NHTSA-2021-0029/document, Docket ID, NHTSA-2021-0029-0001, NHTSA-
2021-0029-0002, and NHTSA-2021-0029-0003.
\26\ Safety Performance of Rechargeable Energy Storage Systems,
DOT HS 812 717, 2019, https://rosap.ntl.bts.gov/view/dot/40791.
---------------------------------------------------------------------------
In contrast to comments that vehicle-level tests are burdensome,
overly costly, and require additional safety measures, NHTSA's testing
program revealed the ease of conducting testing at the vehicle level
multiple times on the same vehicle without significant cost. The
overcharge, over-discharge, overcurrent, over-temperature, and external
short-circuit test procedures in FMVSS No. 305a are non-destructive,
are conducted at ambient temperatures, and can be conducted
sequentially on the same vehicle, minimizing the time and cost of
testing. The tests also include multiple end conditions for design
flexibility. The agency maintains that the requirements are appropriate
to replicate and confirm real-world vehicle operations and do not
constitute an undue burden on manufacturers.
[[Page 104331]]
We understand manufacturers may conduct testing for various
scenarios beyond the requirements of FMVSS No. 305a, and such testing
may be conducted at the vehicle level and/or the component level.
FMVSSs establish minimum safety requirements and the FMVSS test
procedures provide notice to establish how the agency would verify
compliance. However, this does not mean that manufacturers must conduct
the exact test in the FMVSS to certify their vehicles. The Safety Act
requires manufacturers to ensure their vehicles comply with all
applicable FMVSSs and to certify compliance of their vehicles with all
applicable FMVSSs, and the Safety Act specifies that manufacturers may
not certify compliance if, in exercising reasonable care, the
manufacturer has reason to know the certificate is false or misleading.
A manufacturer may use component-level tests to certify its vehicles if
they exercise reasonable care in doing so. In other words, a
manufacturer must ensure that its vehicles will meet the requirements
of FMVSS No. 305a when NHTSA tests the vehicles in accordance with the
test procedures specified in the standard, but the manufacturer may use
different test procedures to do so.
2. State of Charge (SOC)
Proposed Requirements
Initial SOC ranges were specified for each of the proposed test
procedures for vehicles to ensure they have controls managing safe
REESS operations. Some of the SOC ranges differed from those in GTR No.
20 for practicability and ease of conducting the tests. For the
overcharge, over-temperature, and external short-circuit tests, the
REESS is initially at 90 to 95 percent SOC. For the over-discharge
test, the REESS is initially at 10 to 15 percent SOC. For the over-
current test, the REESS is initially at 40 to 45 percent SOC.
Comments Received
Several commenters stated that there should be more flexibility in
the SOC ranges for the tests. Auto Innovators and Honda stated that the
proposed values are too extreme and will likely have already activated
the protections. Auto Innovators requested that NHTSA align the
starting SOC values with those in GTR No. 20. Nissan suggested setting
the starting SOC around the middle of the normal operating range for
the overcharge and external short-circuit tests, as in UNECE Regulation
No.100, because hybrid vehicles may fall outside the range of normal
use if the REESS is initially set between 90 to 95 percent SOC. Bugatti
commented similarly, ``Prescribing absolute values for SoC of the
REESS, without consultation of manufacturer-specified SoC operational
windows, may influence test results due to possible risk for the REESS
to be out of its normal operating SoC range, even from the beginning of
tests.'' Bugatti recommended removing SOC values and taking a similar
approach to UNECE Regulation No. 100, which references manufacturer-
specified SOC.
Agency Response
After reviewing the comments, the agency is adopting the proposed
requirements with a minor modification to the definition of SOC to
clarify the requirements and address commenters' concerns. The initial
SOC specifications in the test procedures refer to the ``operating
SOC,'' or percent charge available under normal operation as it may be
displayed to the user. In other words, the charge level for beginning
each test is based on the normal functional range of the REESS defined
by the manufacturer, not direct measurement of the battery capacity.
This distinction was not sufficiently clear in the NPRM, leading to
concerns about the validity of the test parameters. However, the
specified parameters were tested and validated for different types of
electric vehicles, including HEV and PHEV. These tests included vehicle
crash tests of battery electric vehicles \27\ and tests of vehicle
controls that manage REESS operations and its health.\28\ The initial
SOC ranges are intended to minimize the amount of time needed to
conduct each test. Starting every test in the middle of the normal
operating range rather than the upper or lower portion would lead to
longer test times with no added benefit. In the event that the vehicle
does not display the operating SOC, the charge level can be estimated
using the information provided by the manufacturer.
---------------------------------------------------------------------------
\27\ As an example, see page 2-27 of a NCAP crash test report of
the 2022 Chevrolet Bolt, which indicates that the voltage range
corresponds to the ``usable energy'' of the battery. https://nrd-static.nhtsa.dot.gov/reports/vehdb/v10000/v14200/v14218R001.pdf.
\28\ Electric Vehicle GTR No. 20 Test Development, Validation,
and Assessment, DOT HS 812 092, April 2021, https://rosap.ntl.bts.gov/view/dot/55584.
---------------------------------------------------------------------------
To improve clarity, NHTSA is changing the definition of ``State of
charge'' to mean the available electrical charge in a REESS expressed
as a percentage of the normal operating capacity specified by the
vehicle manufacturer.
3. Breakout Harness Location
Proposed Requirements
The NPRM proposed to conduct the REESS tests using a breakout
harness connected to manufacturer-specified location(s) on the traction
side of the REESS on the vehicle's electric powertrain. The
manufacturer is required to specify the location(s) for connecting the
breakout harness and may also provide an appropriate breakout harness
for testing the vehicle. If the manufacturer does not provide a
breakout harness, NHTSA will use a generic breakout harness to connect
to the traction side of the REESS.
Comments Received
Regarding the overcharge, over-discharge, and overcurrent test
procedures, Honda stated that the term ``traction side'' is too
prescriptive and inconsistent with the proposed test procedure in
S12.5, which did not include the same specification. Auto Innovators
provided the same comment. Prevost requested clarification of the
``traction side'' designation to make clear which systems and
subsystems are considered to be part of the traction side of the REESS
and which are not. An example to clarify is whether the charging inlet
is part of the ``traction side'' of the REESS. Prevost further
suggested making note of a designated location when it is not specified
by the manufacturer.
Agency Response
This final rule adopts the proposed requirements for the breakout
harness location(s) as described in the NPRM, with edits for clarity
and consistency. The ``traction side'' of the REESS refers to the
connection between the REESS and the transmission, so it does not
include the charging inlet. The traction side of the REESS is specified
to ensure that external charging and regenerative charging are both
captured by the test. Regenerative charging can potentially lead to
overcharge conditions even if the vehicle controls prevent overcharging
from the charging inlet. The manufacturer is also required to state the
connection location(s) because a single location would not work for all
vehicles and because connecting the harness to the wrong points of the
powertrain could be damaging and/or hazardous. For the test operators'
safety, ease of testing, and to prevent damage to the vehicle or test
equipment, the manufacturer is required to recommend specific
connection location(s). Although the NPRM clearly stated that the
manufacturer is required to provide connection locations, the proposed
[[Page 104332]]
regulatory text was inconsistent. The text in S12 has been edited to
clarify the requirement. Additionally, because the manufacturer is
required to provide connection locations, no default locations are
necessary. Regarding the exclusion of ``traction side'' in S12.5, that
test is intended to evaluate the response to an external short circuit,
so the traction side specification does not apply. Another possible
source of confusion could be due to the proposed text for S12.5
referencing ``overcharge'' instead of ``external short-circuit;'' the
text has been corrected in the final rule.
4. Over-Temperature Protection
Proposed Requirements
The NPRM proposed to include the over-temperature protection
requirement and test procedure from GTR No. 20, with minor changes.
NHTSA's testing indicated that presoaking the vehicle was not
necessary,\29\ so the NPRM proposed to remove presoaking from the
procedure to reduce the test time and burden. The test procedure
specifies that the test is conducted at ambient temperature, between
10[deg]C and 30[deg]C, with the cooling system disabled or minimized.
The vehicle is driven on a chassis dynamometer using the manufacturer-
provided drive profile, or with aggressive acceleration and
deceleration if an appropriate drive profile is not provided.
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\29\ NHTSA testing demonstrated that presoaking of the vehicle
at elevated temperature does not raise the temperature of the REESS
as significantly as by driving the vehicle under high acceleration
and deceleration drive modes. See System-Level RESS Safety and
Protection Test Procedure Development, Validation, and Assessment-
Final Report. DOT HS 812 782 October 2019. https://rosap.ntl.bts.gov/view/dot/42551.
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Comments Received
Commenters generally agreed with the requirement but recommended
changes to some aspects of the test procedure. MEMA stated agreement
with the agency's decision to remove presoaking, and Auto Innovators
agreed with removing the requirement but said it should be permitted.
Auto Innovators also stated that several provisions were overly
prescriptive and unnecessary, specifically the directions to conduct
the test on a chassis dynamometer and/or in active driving mode, limit
the ambient temperature to 30[deg]C, and specify a one-hour time
period. Honda also disagreed with the limits on the time period and
ambient temperature, stating that there are situations where the
battery temperature will not rise unless the ambient temperature rises.
EMA also suggested modifying the standard cycle specification to allow
a manufacturer supplied drive profile, as ``S12.4 (d) requires using an
appropriate manufacturers supplied drive profile and (h) should follow
the same drive profile or allow for the option to follow the same
manufactured supplied drive profile.'' In an ex-parte meeting,\30\
Nissan commented that it was unclear whether all three test termination
conditions had to be fulfilled to terminate the charge/discharge cycle.
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\30\ Nissan requested to meet with NHTSA to present information
related to the proposed rule. An ex-parte memo has been submitted to
the docket (https://www.regulations.gov/docket/NHTSA-2024-0012).
---------------------------------------------------------------------------
Agency Response
After reviewing the comments, the agency is adopting the proposed
requirements with an additional clarification for the manufacturer-
provided drive profile. The proposed rule defined an appropriate drive
profile by stating that it should raise the temperature of the REESS
above the safe operating temperature within one hour. The test
procedure specifies that the cooling system is disabled or functionally
minimized for testing, but this provision was not stated when defining
an appropriate drive profile. The commenters did not specify if the
REESS cooling system was minimized in their testing. However, the
agency recognizes that some vehicles may not be operable with cooling
reduced to a level that would allow the REESS to overheat under the
specified test conditions. To address commenters' concerns, if it is
not possible to raise the temperature of the REESS without raising the
ambient temperature of the vehicle above 30[deg]C, the manufacturer may
provide a drive profile that would trigger the over-temperature
condition within one hour if the thermal management system were
effectively disabled.
For the performance test, the test termination conditions in FMVSS
No. 305a are identical to those in GTR No. 20, where the vehicle may be
charged and discharged for up to 3 hours. The test time is not limited
to one hour and it is not required to trigger the over-temperature
protection, to avoid penalizing effective thermal management. The test
procedure also does not prohibit presoaking or otherwise specify the
starting temperature of the vehicle. However, the test is conducted at
ambient temperature to avoid the added cost of testing in a heat
chamber. The use of a chassis dynamometer and active driving possible
mode of the vehicle are specified to ensure that the vehicle is tested
in the normal operating state. The termination conditions were
accurately described in the preamble of the NPRM and are the same as
those in GTR No. 20. However, the agency agrees that the proposed
regulatory text did not clearly indicate only one of the termination
conditions needs to be fulfilled to terminate the discharge/charge
cycle. The regulatory text specifying the test methods for evaluating
vehicle controls managing REESS safe operations (S12) have all been
modified to clarify the corresponding termination condition
requirements in the final rule.
Section S12.4(h) of the over-temperature test procedure specifies
conducting a standard cycle, if allowed by the vehicle. A standard
cycle, as defined in GTR No. 20 and FMVSS No. 305a, consists of a
standard discharge followed by a standard charge. The NPRM stated that
the discharge and charge rates used for the standard cycle would be
provided by the vehicle manufacturer. It also specified the alternative
charge and discharge rates that would be used if the manufacturer did
not provide them. The standard cycle is the same for each of the test
procedures addressing safe operation of the REESS and is unrelated to
other test specifications. The definition and use of the standard cycle
are adopted as proposed.
5. Overcurrent Protection
Proposed Requirements
The NPRM proposed to include the overcurrent protection and test
for vehicles capable of charging by direct current (DC) external
electricity supply, as in GTR No. 20. During the test, the REESS is
charged using the battery tester/cycler in accordance with the
manufacturer's recommended charging procedure with the highest normal
charge current specified by the manufacturer, or at a rate of C/3
current if none is provided. After charging is initiated, an over-
current specified by the manufacturer is supplied, or the current is
increased in 10-Ampere steps, until the vehicle over-current protection
terminates charging or the temperature gradient of the REESS is within
4[deg]C for a two-hour period. The standard cycle is then performed, if
possible, and the test concludes with electrical isolation assessment
and a one-hour observation period to assess evidence of electrolyte
leakage, venting, fire, or rupture.
Comments Received
EDTA, MEMA, NEMA, and Eaton suggested expanding the overcurrent
protection requirements to address battery isolation. NEMA said that
the
[[Page 104333]]
contactors can weld, leading to a system protection failure and a
safety issue, and that GTR No. 20 does not offer adequate overcurrent
protection in those cases. Eaton emphasized that contactor failure
occurs frequently, as evidenced by recent vehicle recalls, and
suggested NHTSA require manufacturers to demonstrate they can fully
isolate the positive and negative poles of the battery following a
vehicle crash or overcurrent event. EDTA, MEMA, and NEMA made similar
comments, requesting battery isolation testing and documentation
showing no single point of failure.
Agency Response
After reviewing the comments, the agency is adopting the proposed
requirements. NHTSA agrees with commenters that contactor failure can
lead to system protection failure and a safety issue. However, we do
not see a need to explicitly require ``fully isolat[ing] the positive
and negative poles of the battery following a vehicle crash or
overcurrent event,'' as Eaton and other commenters suggested. The test
procedures in the FMVSS are established to mitigate safety risks in a
manner that is not design restrictive. In the adopted overcurrent test,
the overcurrent is applied until either the protection controls
terminate charging (contactors open), or a long time has passed without
an appreciable change in REESS temperature. Additionally, after the
overcurrent is applied, a standard cycle is performed, if possible,\31\
after which no electrolyte leakage, rupture, venting, fire, or
explosion is permitted during a one-hour observation period. At the
conclusion of the observation period, the electrical isolation is
determined in a similar manner as in FMVSS No. 305, using a voltmeter
to measure the voltages. The agency believes that the termination
criteria for the application of overcurrent and the subsequent
evaluations ensure that the main contactors in the REESS are not fused
due to the overcurrent and therefore mitigate the safety risk. These
requirements are intended to enhance safety while allowing
manufacturers design flexibility.
---------------------------------------------------------------------------
\31\ If the contactor opens when the overcurrent is applied, the
vehicle will not charge/discharge unless the controls are reset.
---------------------------------------------------------------------------
NHTSA will continue to research and assess electric vehicle safety
issues and the need for additional changes to the overcurrent
requirements. NHTSA is also aware of vehicle fires originating at the
vehicle charge inlet while the vehicle is being charged. Some of these
fires have resulted from faulty connections between the charge
connector and the vehicle. As part of NHTSA's Battery Safety
Initiative,\32\ the agency continues to evaluate these safety risks and
potential future agency actions to mitigate these risks.
---------------------------------------------------------------------------
\32\ https://www.nhtsa.gov/battery-safety-initiative.
---------------------------------------------------------------------------
6. Venting and Visual Inspection
Proposed Requirements
Venting is the release of excessive internal pressure from a cell
or REESS in a manner intended by design to preclude rupture or
explosion. Venting during normal vehicle use may result in varying
degrees of safety risks to the vehicle occupant. The NPRM proposed that
each of the tests evaluating vehicle controls for safe REESS operation
(overcharge, over-discharge, overcurrent, over-temperature, and
external short-circuit test procedures) would end with the vehicle
observed for one hour for evidence of electrolyte leakage, rupture,
venting, fire, or explosion, followed by voltage measurements for
determining electrical isolation. NHTSA proposed that there be no
evidence of electrolyte leakage, venting, or rupture that is verified
by visual inspection without disassembly of any part of the vehicle.
Visible smoke during and after the test, and/or the presence of soot
and/or electrolyte residue in post-test visual inspection, are
indicators of venting and electrolyte leakage. The agency acknowledged
that research is needed to develop a repeatable, reproducible, and
practical method to verify the occurrence of various vented gases and
requested comment on the Informal Working Group's continuing work in
Phase 2 of the GTR.
Comments Received
As a whole, commenters agreed that venting detection methods are
challenging to specify at this time and appropriate sensors are still
under development. Auto Innovators stated that the proposed visual
inspection requirement is unnecessary because visible venting is
unlikely. On the other hand, DTNA agreed with the visual inspection
requirement but requested adding a test procedure provision where
venting inspection is captured visually and with written description of
the findings.
With regard to sensor research, Tesla stated agreement with the
agency's assessment that more research is needed, and Nikola said it
doesn't have enough to data to recommend the usage of such sensors for
general application. For future test requirements, Rivian suggested
that the detection method depend on whether the area of concern is the
gas venting within the REESS or the risk of occupant/bystander exposure
to vented gases. Rivian noted that gas detection outside of the REESS
is more challenging than detection inside the REESS and recommended
prioritizing carbon monoxide sensors. Auto Innovators suggested
focusing on a limited number of critical gases, with an emphasis on
release or venting that may impact occupants.
Agency Response
The agency is adopting the proposed requirements for no evidence of
electrolyte leakage, rupture, venting, fire, or explosion as determined
by visual inspection during a one-hour observation period for each of
the vehicle controls for safe REESS operation tests. The commenters
agreed that appropriate sensors and procedures for detection of vented
gases are not currently available and that more research is needed.
NHTSA is continuing to investigate gas detection methods and potential
test procedures to address venting of hazardous gases such as carbon
monoxide. This research will inform future rulemaking. At this time,
the agency believes inclusion of the visual inspection requirement
enhances safety protection to limit safety risk to vehicle occupants
due to venting and should remain a minimum requirement until
quantitative detection methods are fully developed. As with similar
standards, the compliance test procedures will include recording of the
visual inspection results, using detailed descriptions, video, and/or
photographs as appropriate.
d. Mitigating Risk of Thermal Propagation Due to Internal Short Within
a Single Cell in the REESS
Proposed Requirements
The NPRM proposed documentation requirements for risk mitigation of
thermal propagation events resulting from single-cell thermal runaway
(SCTR) due to an internal short circuit within a cell in the REESS.
NHTSA's proposed documentation component structure is based on elements
from GTR No. 20, ISO-6469-1: Amendment 1
[[Page 104334]]
2022-11,\33\ and ISO-26262.\34\ The documentation submitted by the
manufacturer is required to include all known risks to vehicle
occupants and bystanders, risk assessment, risk management, and risk
mitigation strategies in external charging mode, active driving
possible mode, and parking mode. The objective of the documentation
requirements is for vehicle manufacturers to identify the risks of
single-cell thermal runaway and propagation for their REESS type,
identify strategies to mitigate those risks, and demonstrate how those
strategies work. The manufacturers' assessment and validation of risk
mitigation strategies may involve a combination of physical testing and
simulations at the component level and/or full vehicle level. The
requirements are not design restrictive and apply to REESSs of all
types.
---------------------------------------------------------------------------
\33\ ISO 6469-1: Third Edition 2019-04 Amendment 1 2022-11,
``Electrically propelled road vehicles--Safety specifications--Part
1: Rechargeable energy storage system (RESS),'' specifies safety
requirements for REESSs, including test methodology for initiating
thermal runaway in a cell for the purpose of conducting a thermal
runaway propagation test and a format for reporting on risk
mitigation strategies of thermal propagation resulting from a
thermal runaway in a single cell of an REESS due to an internal
short within the cell.
\34\ ISO 26262: 2018, ``Road vehicles--Functional safety,''
provides a comprehensive collection of standards to manage and
implement road vehicle functional safety from concept phase to
production and operation. The standard provides guidelines for
overall risk management, individual component development,
production, operation, and service.
---------------------------------------------------------------------------
Comments Received
There were several comments on SCTR risk mitigation documentation,
including multiple requests for clarification. Tesla, HATCI, and
Honeywell stated support for the proposed documentation approach.
However, HATCI disagreed with the addition of the two new operation
modes, stating they are unlikely to add material safety benefits while
unnecessarily increasing the test and documentation burden, whereas
Honeywell said the addition acknowledges the need to identify distinct
risks and mitigations for each operational mode. Nissan suggested that
NHTSA add a detailed description of safety risks ``such as fire,
explosion, or smoke'' to enhance clarity regarding the severity of
these risks in S13.1. Lubrizol stated strong support for the
requirements proposed in the NPRM and provided graphs demonstrating the
performance of their fluids for immersed thermal management of the
REESS.
Auto Innovators questioned the necessity of the SCTR requirement
given the inclusion of other thermal runaway and propagation
requirements (e.g., the requirement for a thermal event warning), and
asked the agency to provide additional research to support the
inclusion of this requirement, though it also said that the proposed
reporting requirements appear to be reasonable. Additionally, Auto
Innovators said the requirement should not apply to Ni-MH batteries
because the electrolyte generally used in Ni-MH batteries is not
flammable; Auto Innovators noted that GTR No. 20 and industry standards
limited the requirement to flammable electrolyte REESS and that
internal short-circuits are less likely in Ni-MH batteries due to
greater spacing of the electrodes. Auto Innovators further requested
clarification on several aspects of the requirements, including risks,
validation strategies, and terminology where the FMVSS deviates from
GTR No. 20. Auto Innovators said the term ``vehicle power'' in the
definition of parking mode is ambiguous and could mean any voltage or
just high voltage. Auto Innovators also said there should be processes
for updates or corrections, the requirements should not be limiting,
and providing confidential business information should not be required
if the information is subject to public disclosure.
Lucid and NFA also requested further clarification of the
requirements. Lucid said, ``As proposed, the requirements could lead to
either over- or under-reporting. Lucid stresses the importance of
delineating the documentation requirement under Part IV, overall
evaluation of risk mitigation, to avoid conflation with risk mitigation
itself.'' NFA likewise suggested that NHTSA define ``the requisite
detail level within the SCTR Risk Assessment and Mitigation
documentation of the Proposal, with the expectation that it aligns with
established best practices and industrial standards, such as ISO 26262
or SAE J1739.'' NFA also stated that the vehicle manufacturers will
need information from the REESS manufacturer and NHTSA should follow
the confidential document treatment procedure of 49 CFR part 512 to
protect proprietary information. Nikola agreed that it makes sense to
not require a warning for SCTR and that a thermal runaway warning
should be required. Nikola suggested a battery manufacturer requirement
similar to the UL 2580 SCTR test, which forces a cell into thermal
runaway. Similar to NFA, Nikola expressed concerns about obtaining
proprietary information from battery manufacturers and suggested
Confidential Business Information treatment per 49 CFR part 512.
Agency Response
For the final rule, the agency is adopting the proposed risk
mitigation documentation requirements. However, instead of including
the documentation requirements in FMVSS No. 305a as proposed, this
final rule includes the risk mitigation documentation requirements in
part 561. The purpose of these documentation requirements is to ensure
that manufacturers have considered and addressed the risk of SCTR due
to an internal short circuit, as the risk is highly dependent on REESS
design and there is no one field-relevant performance test that can be
applied to all REESS designs in a repeatable and reproducible manner.
NHTSA-funded research examined various existing methods of initiating
thermal runaway, including the heating element method, rapid heater
method, nail penetration, and laser method, on batteries with a variety
of chemistries, formats, and configurations.\35\ The agency's research
indicated that the thermal runaway initiation methods may influence the
test results and the most appropriate initiation method for a battery
may depend on the battery chemistry, format, and configuration. Nikola
referenced a private industry developed standard, UL 2580 ``Standard
for batteries for use in electric vehicles,'' as a potential
requirement for battery manufacturers. Among other requirements, UL
2580 specifies a test where a single cell is forced into thermal
runaway, by any means recommended by the battery manufacturer, with a
requirement for no evidence of fire or explosion for 1 hour after
initiating thermal runaway. Such a test is not appropriate as a
compliance test procedure because some thermal runaway initiation
methods employed may require advanced equipment and knowledge of the
REESS that is only available to the manufacturer. It is also difficult
to establish objectivity and could be design restrictive. However,
manufacturers may voluntarily use any or all of the tests in UL 2580
for validating risk mitigation strategies in their documentation
submitted to the agency. For these reasons, the agency is not requiring
a performance test for thermal runaway of a single cell.
---------------------------------------------------------------------------
\35\ Lamb, J., Torres-Castro, L., Stanley J., Grosso, C, Gray,
L., ``Evaluation of Multi-Cell Failure Propagation,'' Sandia Report
SAND2020-2802, March 2020. https://www.osti.gov/servlets/purl/1605985.
---------------------------------------------------------------------------
Regarding the need for SCTR risk mitigation requirements given the
other requirements in the proposal, including
[[Page 104335]]
warning for a thermal event in the REESS, the agency believes a
requirement to mitigate the risk of SCTR due to an internal short
circuit is needed because: (1) there have been a number of electric
vehicle fires in the field resulting from a short circuit within a cell
in the REESS of vehicles in parking, charging, and driving modes, (2)
none of the performance test requirements for the safe operation of the
REESS (overcharge, over-discharge, overcurrent, external short-circuit
tests) address SCTR and thermal propagation resulting from an internal
short circuit, and (3) the thermal event warning is required when the
vehicle is in the active driving possible mode to allow vehicle
occupants to safely egress, but does not address prevention of vehicle
fire.
With regard to specific battery chemistries, the documentation
requirements for SCTR are battery chemistry neutral. Safety risks need
to be evaluated and mitigated for all types of vehicle REESS,
regardless of chemistry, to minimize the possibility of hazardous
conditions. Gas venting, explosion, or other hazards can occur even
without flammable electrolyte. The documentation requirements include
identification of safety risks and mitigation strategies. If a REESS
uses non-flammable electrolyte and the REESS cells have large spacing
between electrodes, those elements may be included as primary risk
mitigation strategies in the required documentation. Primary risk
mitigation strategies include manufacturing quality control to mitigate
defects in cells of REESS, REESS design features such as heat sinks,
cell spacing, coolant, advanced battery management system with
prognostics, and diagnostics systems to manage the health of the cells
of an REESS and detect a possible thermal runaway condition before it
occurs. Primary risk mitigation strategies reduce the risk of SCTR due
to an internal short circuit and the occurrence of thermal propagation
that may result from SCTR, while secondary risk mitigation strategies
may not reduce the risk of thermal runaway or thermal propagation but
reduce the hazards associated with thermal propagation. Secondary risk
mitigation strategies include warning systems to vehicle occupants/
bystanders and/or notification to emergency personnel in the event of
thermal propagation (e.g., automatic notification to 911 operators).
The NPRM provided examples of mitigation strategies, but specific
strategies are not mandated, allowing flexibility and practicability of
various battery chemistry and battery systems without limiting only
certain risk mitigation strategies known now. The risk reduction
analysis requirement follows industry standard methodology.\36\
---------------------------------------------------------------------------
\36\ ISO 26262, ``Road vehicles--Functional safety,'' provides a
comprehensive collection of standards to manage and implement road
vehicle functional safety from concept phase to production and
operation. The standard provides guidelines for overall risk
management, individual component development, production, operation,
and service. https://webstore.ansi.org/industry/automotive/electric/safety/functional-safety-iso-26262?psafe_param=1&gad_source=1&gclid=Cj0KCQjw99e4BhDiARIsAISE7P_bipjmLqkehMPUorfq0x2h6lAVWmd0GSbo7Z7qRtwAI-Rfd40YBMUaAuMuEALw_wcB.
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As previously stated, the requirements are based on those from GTR
No. 20. NHTSA extended the requirements to include consideration of the
external charging and parking modes to ensure safety under all normal
vehicle operating conditions. The incremental amount of documentation
from adding other operating modes is minimal. The operating modes were
defined in the NPRM, with Parking mode defined as ``the vehicle mode in
which the vehicle power is turned off, the vehicle propulsion system
and ancillary equipment such as the radio are not operational, and the
vehicle is stationary.'' Per this definition, both the high-voltage and
the low-voltage power are turned off. The regulatory text also
describes the information to include in each section of the
documentation for completeness, from system diagrams to validation of
risk mitigation strategies. As proposed, the required documentation is
to be submitted upon request. Documentation containing proprietary
information can be submitted as Confidential Business Information (CBI)
under 49 CFR part 512 and will be handled accordingly. Documentation
submission, regulations, and CBI are discussed further in Section k.
e. Thermal Event Warning
Proposed Requirements
As part of a risk-mitigation approach addressing multiple aspects
of electrical system safety, the NPRM proposed a performance
requirement for a thermal event warning. The term ``thermal event''
refers to a condition when the temperature within the REESS is
significantly higher (as defined by the manufacturer) than the maximum
operating temperature specified by the manufacturer. Thermal events may
occur due to moisture and dust accumulation that causes a short circuit
at the connections or electronic components within the REESS. A thermal
event within a battery pack can be a safety critical event, as it can
lead to smoke, fire, and/or explosion. A warning provided when a
thermal event within the REESS occurs while the vehicle is in active
driving possible mode would reduce the likelihood of occupant exposure
to hazardous smoke, fire, and/or explosion. NHTSA also proposed that
the visual warnings be provided to all front row occupants for vehicles
with automated driving systems without manually operated driving
controls.
Comments Received
There were many comments on the proposed thermal event warning
test. Comments from Consumer Reports, Lucid, and EMA stated support for
the actual audio-visual warning. Consumer Reports also suggested that
NHTSA work with manufacturers to ensure all warnings are sufficiently
prominent and convey the severity of the event. SAVE Coalition agreed
with the warning overall but noted that it was only directed to the
driver of the vehicle. To include vehicles equipped with automated
driving systems, SAVE Coalition suggested adding, ``For a vehicle
without manually operated driving controls, the warning must be
provided to occupants in all outboard designated seating positions.''
On the other hand, Auto Innovators said, ``We recommend remove
requirements for AVs without manual driving controls; NHTSA has not
provided rationale for why any warning needs to be provided to the
`front row occupant'; the occupant cannot take any action based on the
visual warning.'' Honeywell suggested adding an auditory warning
requirement for active charging and parking modes to enable relocation
of adjacent vehicles, evacuation of building occupants, and alerts to
bystanders. ACIL likewise encouraged NHTSA to include requirements for
a warning to vehicle occupants and/or bystanders outside the vehicle in
the event of thermal propagation.
Some commenters said that the NPRM discussion of ``thermal
runaway,'' ``thermal propagation,'' and ``thermal event'' was unclear.
Nissan suggested that sections S13.2 and S13.3 for the thermal event
warning should be distinct from S13, thermal propagation safety, to
ensure clarity and precision in addressing thermal safety risks within
the documentation. Nikola said, ``NHTSA is proposing to not have a
warning for a thermal runaway but to require one for thermal event that
is intended to inform occupants to egress the vehicle. The definitions
of Thermal event and Thermal Runaway are being
[[Page 104336]]
conflated.'' NFA likewise stated that there appeared to be a
discrepancy in NHTSA's statements about the relevance of SCTR and
thermal event warnings.
Many comments disagreed with the parameters of the proposed test
requirement. Auto Innovators said the NPRM did not provide references
or otherwise explain the test parameters. They noted that battery
modifications can be risky and suggested slower heating due to
``concerns with the proposed test method of using a heater that
abruptly achieves 600C within 30 seconds [which] could result in
unstable test conditions.'' NFA said that the three-minute timeframe
seems arbitrary and uncorrelated with occupant hazard exposure, and
suggested using the SCTR thermal propagation criteria from ECE R100.
Tesla, HATCI, Honeywell, ZETA, Lucid, Nikola, and Honda all expressed
similar concerns over the timing and occurrence of actual thermal
runaway and propagation with the proposed test procedure. Some
suggested other initiation methods or a ramp of 180 seconds as in GTR
No. 20. Nissan said the temperature specification was too high. Honda
recommended clarification that the temperature specification refers to
the heater temperature, not the REESS temperature. Honda also requested
clarification on allowable modifications to the REESS, including
replacement of one or more cells with heater equipment preinstalled for
accurate test results. Similarly, Bugatti requested ``a clear
definition of thermal runaway condition and confirmation whether
instrumented cells will be allowed to recognize this event,'' to ensure
that manufacturers have flexibility to accommodate the test equipment
if NHTSA does not allow other triggering methods.
Several vehicle and component manufacturers said that the vehicle-
level test requirement is unnecessarily dangerous. MEMA said that the
test would generate toxic smoke and other potentially unsafe conditions
for test personnel, and contradicts other requirements to mitigate or
stop thermal runaway. Ford said the heater test is ``unnecessarily
destructive and burdensome in that it requires the initiation of a
thermal runaway to confirm the illumination of a warning light,'' and
recommended verification using an electronic signal instead. Prevost
also expressed safety concerns, noted additional difficulty in testing
heavy vehicles, and suggested a subsystem test. EMA suggested a
documentation requirement or component-level test, as the full-vehicle
test could destroy the vehicle and introduce an unsafe situation. Many
other commenters also recommended implementing the documentation
requirement from GTR No. 20 due to issues with the proposed test
requirement.
Agency Response
After consideration of the comments, the agency is not adopting the
proposed performance test requirement for the thermal event warning but
is implementing a corresponding documentation requirement in part 561
instead. While the agency maintains the importance of the required
thermal event warning, commenters raised concerns about the proposed
test method and safety of testing. The agency agrees that additional
research is needed to ensure that any performance test for the thermal
event warning is well-defined, appropriate for all vehicles, and does
not pose an undue risk to test personnel. In turn, the documentation
requirements are adopted for the final rule.
The documentation requirements for the audio-visual thermal event
warning are similar to those in GTR No. 20. Manufacturers are required
to provide documentation to the agency, upon request, with a detailed
description of the system for triggering the warning. Specifically, the
documentation requirements include parameters and associated threshold
levels that are used to indicate a thermal event (e.g., temperature,
temperature rise rate, SOC level, voltage drop, electrical current,
etc.) to trigger the warning, as well as a system diagram and written
explanation describing the sensors and operation of the vehicle
controls that manage the REESS in the event of a thermal event.
The primary purpose of the adopted warning is to ensure occupants
have sufficient time to exit the vehicle to minimize direct exposure to
potential hazards. The warning is to be provided regardless of the
cause of the thermal event. A thermal event in the REESS can lead to
smoke, fire, and/or explosion, and a warning can reduce the likelihood
of occupant exposure to these safety hazards. The audio-visual warning
is provided to the driver, or to all front row occupants in the case of
autonomous vehicles without manually operated controls, notifying of a
thermal event in the REESS when the vehicle is in active driving
possible mode. The agency believes this specification is appropriate to
ensure the driver or the front row occupants in vehicles with automated
driving systems without manually operated controls are alerted of the
potential safety hazard to ensure the driver or occupants can stop and
exit the vehicle. The front row provision for vehicles with automated
driving systems is aligned with other FMVSSs \37\ and may be revised
over time. The primary purpose of the adopted warning is to ensure
occupants have sufficient time to exit the vehicle to minimize direct
exposure to potential hazards. Activation of a warning to bystanders
outside the vehicle was not proposed in the NPRM and is not in scope
for this final rule. Additionally, further research needs to be
conducted to determine the type and efficacy of such a warning to
people outside the vehicle.
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\37\ See requirements in S9.2.2 of FMVSS No. 208 with regard to
the air bag suppression telltale. The telltale is required to be
visible to the front outboard passengers.
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Some commenters said the discussion in the NPRM was unclear between
the term of thermal event and SCTR and the corresponding warning
requirements. Section 2 of the NPRM addressed thermal propagation from
SCTR due to an internal short circuit within the cell; this is a
specific hazard that can be minimized by risk evaluation and mitigation
in design and manufacturing. Risk mitigation includes implementing
strategies to prevent SCTR and to isolate a cell that is in thermal
runaway to prevent thermal propagation. A warning specifically for SCTR
is not required. However, any instance of thermal runaway and
propagation that occurs, regardless of the cause, should trigger the
thermal event warning for the vehicle occupants' safety. To minimize
confusion, the documentation requirements for the thermal event warning
and for SCTR risk mitigation are adopted in separate sections of part
561.
f. Vehicle Control Malfunction Warning
Proposed Requirements
The NPRM proposed a documentation requirement for a driver warning
in the event of a malfunction of vehicle controls that manages the safe
operation of the REESS. The warning documentation requirement is
similar to GTR No. 20, with two added provisions, and is an interim
measure intended to ensure that manufacturers will identify, address,
and validate the effectiveness of their visual warnings that help
manage safe REESS operation. This approach is intended to evolve over
time as battery technologies and NHTSA's information about the REESS
safety risk mitigation strategies evolve.
Comments Received
Comments on the vehicle control malfunction warning documentation
requirement were positive. Nikola
[[Page 104337]]
agreed with requiring a warning, stating that it already provides
malfunction warnings to the driver and documents all the information in
the monitoring and diagnostic documents required by the California Air
Resources Board for powertrains. Tesla stated support for including the
requirements in FMVSS No. 305a because they apply to all REESSs
irrespective of crash conditions. HATCI and Auto Innovators also stated
support for the proposed documentation requirements. Auto Innovators
agreed that there is currently no practical test procedure and stated
support for the documentation approach.
Agency Response
The agency is adopting the proposed requirements for a driver
warning in the event of a malfunction of vehicle controls that manage
the safe operation of the REESS. Commenters agreed that the warning and
documentation requirement are appropriate and indicated that they may
already maintain and produce such documentation as required by other
regulations. For the final rule, the vehicle control malfunction
warning requirements are adopted in FMVSS No. 305a and part 561.
g. Protection Against Water Exposure
Proposed Requirements
The NPRM proposed water exposure test requirements, where a vehicle
shall maintain electrical isolation resistance after the vehicle is
exposed to water under normal vehicle operation, such as in a car wash
or while driving through a pool of standing water. As in GTR No. 20,
the proposed test procedures specify the use of freshwater. The
proposed physical test requirements comprised of two tests. The
proposed washing test was similar to that in GTR No. 20, with the
addition of exposing the vehicle underbody to the water stream to make
the test more representative of vehicle washing. The proposed driving
through standing water test was also similar to that in GTR No. 20, but
with the maximum test duration reduced from 10 minutes to 5 minutes.
Electrical isolation was proposed to be determined at the conclusion of
each test, and once again after 24 hours.
The NPRM did not propose to allow the documentation or isolation
loss warning compliance options from GTR No. 20 for the water exposure
tests. The NPRM requested comment on the proposed test specifications,
including water pressure for the washing test. The NPRM also requested
comment on water salinity levels for the tests as well as potential
test procedures for submersion.
Comments Received
There were a variety of comments on the water exposure
requirements. Some commenters agreed with the proposed test procedures,
while others requested additional compliance options or changes to the
test specifications. For the washing test, Tesla stated support for the
proposed test method and recommended keeping the freshwater
specification from GTR No. 20. Auto Innovators suggested establishing a
maximum test duration and changing the timing of the isolation checks
to 12 hours to reduce the time burden. Auto Innovators said the test
parameters should not include salinity because it is unnecessary and
because a large amount of water will be needed, and the reproducibility
of salinity levels is challenging. Nissan also said that using saline
in the proposed tests would not significantly impact the evaluation and
is unnecessary.
Hyundai requested clarification for the underbody spray distance
and angle for the proposed test procedure to ensure the test is clear
and repeatable. For water pressure, Eaton agreed with adopting IPX5 for
normal driving conditions. NEMA also agreed that IPX5 matches normal
conditions but suggested using IPX7 to address submersion concerns.
Nikola said, ``Increasing the pressure does seem prudent as it will be
the standard practice to use a pressure washer to clean the vehicles,''
and suggested IPX6.
Eaton stated support for the inclusion of the driving through
standing water test. Tesla also agreed with the proposed procedure and
suggested keeping the long rectangular pool for ease of defining
driving and test evaluation methodologies. As with the washing test,
Auto Innovators said there should not be a salinity requirement and
requested changing the timing of the isolation checks to 12 hours.
Prevost and EMA opposed the driving through standing water test for
heavy vehicles. Prevost said, ``Since NHTSA suggests improving vehicle
washing test by adding the underside of the vehicle to the scope of the
test, the driving through standing water tests does not seem to add
value to the safety of the vehicle, as the washing test with the
underbody included will be a harsher requirement than driving through
10cm of water at 20kph . . . Since facilities providing the
infrastructures to perform the driving through standing water test will
be scarce, this test would add significant costs while not improving
vehicle safety.'' EMA likewise stated that the washing test is more
aggressive, test facilities for heavy vehicles do not currently exist,
and NHTSA should remove the redundant and expensive driving through
standing water test for heavy vehicles.
Auto Innovators, Hyundai, Nissan, and NFA requested inclusion of
compliance options from GTR No. 20. Hyundai recommended harmonizing
with GTR No. 20 and UNECE R100, in which the electrical isolation loss
warning system is allowed as a compliance option. Nissan similarly
requested a compliance option to harmonize with the UNECE. Auto
Innovators asked that NHTSA allow a component-level test compliance
option, and transit bus manufacturer NFA specifically requested
component-level water exposure safety tests instead of full vehicle
tests for heavy buses and motor coaches. NFA asserted that spraying the
battery pack directly would constitute a more rigorous test than the
proposed full-vehicle tests and said it is open to component-level
testing at the IPX6 level.
With regard to submersion concerns, commenters generally agreed
that further research is necessary, and some urged NHTSA to commit to a
technical amendment. Auto Innovators said that more analysis is needed
before determining whether additional test requirements should be
implemented and recommended harmonizing with UNECE R100. EDTA
recommended that NHTSA commit to a technical amendment and collaborate
with stakeholders in collecting data to establish a test requirement
addressing real-world flooding scenarios. MEMA, NEMA, and Eaton
provided similar comments. Eaton also stated that rigorous test
standards would enable the United States to maintain a position of
technological leadership and prevent lower-quality imports from
entering the market. NEMA said that testing documentation requirements
should include water ingress and egress risks. Nikola said that
submersion in saline should be compared to the salt spray test in
UL2580. Tesla also recommended additional research on salinity. MEMA,
NEMA, EDTA, and Eaton further recommended adding a leak check
requirement for battery packs at the time of manufacture. MEMA and
Eaton specified that the leak checks should include all sealing
surfaces and be implemented as a documentation requirement; Eaton said
the sealing surfaces between vent valves and the battery housing are
often missed in current leak testing practices.
[[Page 104338]]
Agency Response
After consideration of the comments, the agency believes the
proposed test procedures remains practicable and the requirements
mitigate the risk of short circuit or loss of electrical isolation due
to water ingress under normal operating scenarios such as driving
through standing water on the road or vehicle washing. NHTSA is
adopting the proposed requirements with minor changes, including an
increase of the standing water test maximum duration from 5 minutes to
10 minutes due to recent NHTSA testing. For the vehicle washing test,
the NPRM included a figure from GTR No. 20 to specify the dimensions of
the water nozzle and stated that the ``nozzle specifications are from
IEC 60529 for IPX5 water jet nozzle.'' However, the provided figure
depicted the nozzle dimensions from IEC 60034, wherein one internal
dimension of the nozzle deviates from IEC 60529 by 2 mm. As IEC 60034
is specific to rotating electrical machines, it is more appropriate to
use the nozzle specifications from IEC 60529, which was the standard
referenced in the text of the NPRM. For these reasons, this final rule
contains a corrected figure specifying water nozzle dimensions
consistent with IEC 60529.
The NPRM proposed a maximum test duration of 5 minutes for the
driving through standing water test instead of GTR No. 20's 10 minutes
but also sought comment on the maximum duration. NHTSA conducted the
driving through standing water test in August 2024 using a 30-meter
length water pool with a 15-meter approach ramp on both ends of the
pool.\38\ To accumulate 500 meters of driving through 10 cm of standing
water, the vehicle needed to be driven 17 times through the 30-meter
water pool. Based on the testing, the agency determined that a test
duration of 5 minutes may not be sufficient when the test is conducted
using a short water pool. Traversing the entry and exit ramps and
turning around between each pass of the water pool adds to the total
time necessary to complete the test. NHTSA estimates that 7.5 minutes
is sufficient for a water pool length of 30 meters. More time would be
needed to complete the test using water pools shorter than 30 meters.
The maximum test duration time for conducting the driving through
standing water test is 10 minutes in GTR No. 20, which NHTSA agrees is
appropriate. Therefore, this final rule adopts a 10-minute time limit
for the driving through standing water test.
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\38\ The testing is described in more detail in a separate
document being placed in the docket for this rulemaking.
---------------------------------------------------------------------------
Some comments addressed other parameters of the vehicle washing
test, specifically test time, spray angle, and spray distance. The
maximum test time is not stated because the test procedure specifies
``washing test duration per square meter of the vehicle surface area is
60 to 75 seconds.'' The maximum test time depends on the surface area
of the vehicle, which can be measured in square meters and multiplied
by 75 seconds per square meter to obtain the maximum test duration for
the vehicle. The spray angle provision ensures that all directions are
considered for water resistance and is consistent with the IPX5
standard and GTR No. 20. The test procedure states, ``The vehicle is
sprayed from any direction,'' which means the vehicle must be able to
meet the test requirements regardless of the angles used. With regard
to the spray distance, the proposed requirement said, ``the distance
from the nozzle to the vehicle surface is 3.0 to 3.2 meters [and] may
be reduced, if necessary, to ensure the surface is wet when spraying
upwards.'' The test procedure includes some adjustment to the nozzle
distance because the water stream may not be capable of hitting a
vehicle's lower side and bottom (underbody) unless the nozzle is
pointed upwards and positioned closer than 3.0 to 3.2 meters from these
vehicle surface areas. These provisions are consistent with GTR No. 20.
Further, NHTSA believes the proposed testing parameters provide
sufficient specification and flexibility for a repeatable test, thus,
the agency is adopting the proposed specification.
Regarding the time interval between isolation measurements, Auto
Innovators did not provide any supporting data for the request to
reduce the minimum wait time to 12 hours. The isolation measurements
are conducted immediately after water exposure and after a minimum of
24 hours, which is identical to the GTR No. 20 and ECE R.100
specifications. The agency believes that the 24-hour wait time is
appropriate and consistent with observed electric vehicle fires
initiating a day or longer after water exposure/submersion.\39\ In the
absence of information demonstrating that reducing the time interval
between isolation measurements would not significantly alter the test
results, the agency is adopting the requirements as proposed.
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\39\ Overview of NHTSA EV Safety Activities, SAE Government
Industry Meeting, January 2023, https://www.nhtsa.gov/sites/nhtsa.gov/files/2023-03/15874-NHTSA%20SAE%20GIM%202023_final_032223-tag.pdf.
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Some commenters supported the addition of a warning option.
Although visual warning indicators triggered from an isolation
monitoring system could help mitigate safety concerns, NHTSA believes
that this approach is not sufficient to solely mitigate a shock or fire
hazard caused by the effects of water exposure. Consequently, the
agency is not adopting the loss of isolation warning compliance option
because warning signals alone are not sufficient for addressing loss of
electrical isolation concerns.
Some commenters also requested component-level testing,
particularly for heavy vehicles. The agency believes that component-
level testing is not as representative of actual conditions as full-
vehicle testing. Furthermore, the vehicle washing test does not pose an
undue burden.
The agency also disagrees with EMA and Prevost's requests that
heavy vehicles be excluded from the driving through standing water
test. In support of their position, the two commenters said that test
facilities do not accommodate heavy vehicles, it would be very
expensive to conduct the test, and the test is redundant. The agency
notes that FMVSSs establish minimum safety requirements and the FMVSS
test procedures establish how the agency would verify compliance. The
Safety Act requires manufacturers to ensure their vehicles comply with
all applicable FMVSSs and to certify compliance of their vehicles with
all applicable FMVSSs. The Safety Act specifies that manufacturers may
not certify compliance if, in exercising reasonable care, the
manufacturer has reason to know the certificate is false or misleading.
A manufacturer may use component-level tests to certify its vehicles if
they exercise reasonable care in doing so. Additionally, while NHTSA
agrees that the driving through standing water test may not be as
stringent as vehicle washing for certain heavy vehicle configurations
with greater ground clearance and/or with the REESS located higher on
the vehicle (e.g., on the roof), vehicle configuration is not
prescribed by the FMVSS and is left to the discretion of the
manufacturer. Both water exposure tests represent reasonable scenarios
for normal vehicle operations and establish minimum levels of safety
for water exposure of electric vehicles. With the flexibilities
afforded to manufacturers to certify compliance, NHTSA disagrees that
the cost burden may be excessive for heavy vehicles. Some vehicle
manufacturers suggested use of the IPX6
[[Page 104339]]
or IPX7 standard instead of IPX5. NHTSA agrees that other standards
such as IPX6 or IPX7 may be appropriate for evaluating the water
resistance of electric vehicles. However, the corresponding IPX6 or
IPX7 test procedures were not proposed in the NPRM and are out of scope
for this final rule. While the final rule adopts the proposed
requirements corresponding to IPX5, manufacturers are not prohibited
from additional test methods beyond the FMVSS specifications and may
choose to use the IPX6 or IPX7 standard to evaluate the water
resistance of their vehicles.
The commenters agreed that saline should not be specified for the
test procedures because it would not significantly affect the results
and the salinity level would be difficult to maintain. The commenters
also observed that the test procedures of using fresh water would
harmonize with international standards. At this time, the agency agrees
that generally, water exposure under normal vehicle operation occurs
with freshwater; thus, keeping the freshwater specification is
appropriate for these tests.
With regard to the battery leak check requirements suggested by
some commenters, such requirements were not proposed in the NPRM and
are also out of scope for this final rule. Typical leak check
procedures require access via one of the vent valves; a requirement to
check all sealing surfaces would necessitate a different test method
that does not use an opening in the pack. Additionally, research on
flood-damaged vehicles has shown that water ingress occurs for a
variety of reasons and does not necessarily lead to catastrophic
failure.\40\
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\40\ A Teardown Study of Flood Damaged Electric Vehicles--EV
Battery Safety, Part 2, SAE Government Industry Meeting, January
2024, https://www.nhtsa.gov/document/teardown-study-flood-damaged-electric-vehicles-ev-battery-safety-part-2.
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NHTSA recognizes that further research is needed on the field
incidences of electric vehicle fires following water exposure,
particularly saltwater exposure, in order to establish additional
requirements. NHTSA is taking the first step by adopting the proposed
water exposure requirements for normal vehicle operations and continues
to research salinity, immersion, and test procedures to support the
development of future safety requirements and inform potential updates
to the FMVSS.
h. Miscellaneous GTR No. 20 Provisions Not Proposed
The NPRM did not propose to require some provisions from GTR No. 20
for vibration, thermal shock and cycling, fire resistance, and low
state of charge (SOC) of the REESS during normal vehicle operations.
The NPRM requested comment on these exclusions.
j. Vibration and Thermal Shock and Cycling
NPRM Discussion
As stated in the NPRM, GTR No. 20 contains a vibration requirement
and test procedure that applies a generic vertical vibration profile to
the tested vehicle. NHTSA believes that this test is not representative
of real-world conditions. In addition, vehicle manufacturers routinely
perform vibration testing to ensure customer satisfaction and
reliability. At the component level, electric vehicle batteries are
currently subject to vibration test requirements for transportation
under the United States Hazardous Materials Regulations (HMR), along
all three orthogonal axes and for frequencies up to 200 Hz. With these
current tests, NHTSA does not believe that the GTR No. 20 vibration
test would address an additional safety need.
Similarly, at the component level, REESSs are already subject to
thermal cycling test requirements for transportation under the HMR. 49
CFR 173.185 requires lithium-ion cells and batteries to comply with the
test requirements in UN 38.3, including Test T2: Thermal test, which is
the basis of the GTR No. 20 thermal shock and cycling test and includes
a larger temperature range. NHTSA believes that incorporating the GTR
No. 20 test would not address an additional safety need.
Comments Received
Comments from Auto Innovators and HATCI stated agreement with the
agency's rationale and exclusion of these requirements. Regarding the
vibration and thermal shock and cycling requirements of GTR No. 20,
HATCI agreed with NHTSA's rationale for not including the tests given
the more stringent U.S. regulations. Auto Innovators also agreed that
introduction of new vibration profiles is unnecessary, as the test may
not be representative of real-world conditions and industry uses other
means to assess durability. For thermal shock and cycling, Auto
Innovators said the test requirements in UN 38.3 T2 are sufficient.
However, Nikola disagreed with the agency's decision not to add the
thermal shock and cycling test. Nikola said that the HMR requirements
are insufficient because UN 38.3 does not require testing of the
assembled battery pack, and that relying on the shipping requirements
for the cells or modules is a low bar to set for safety.
Agency Response
After reviewing the comments, the agency is not adopting additional
requirements for vibration and thermal shock and cycling. Commenters
agreed with the agency's rationale for excluding the vibration test
requirements. Nikola said the thermal shock and cycling test
requirements in GTR No. 20 should be included because testing of cells
or modules is not equivalent to testing of the full battery pack; UN
38.3 does not require pack level testing if the cells and modules were
tested. However, Nikola did not provide any data demonstrating that the
existing requirements may be insufficient. For the final rule, the
agency does not believe there is a safety need for additional thermal
shock and cycling test requirements. In the absence of new supporting
information, NHTSA maintains that UN 38.3 and the HMR appropriately
address resistance to thermal shock and cycling for lithium cells and
batteries.
2. Fire Resistance
NPRM Discussion
The GTR No. 20 fire resistance requirement applies to REESSs with
flammable electrolyte installed in a vehicle at a height less than 1.5
m above the ground and is based on a UN Regulation for liquid fueled
vehicles with plastic tanks. During the test, the REESS is exposed to a
flame directly for 70 seconds and indirectly for 60 seconds. As stated
in the NPRM, vehicle testing by Transport Canada indicated that the
short duration of the external fire test would not result in explosion.
Consequently, during Phase 1 of the GTR No. 20 discussions, the United
States and Canada noted that the short duration component level test
would not address a safety need and recommended removing it from GTR
No. 20.
Comments Received
As with the vibration and thermal shock and cycling tests, HATCI
expressed agreement with NHTSA's decision not to include the fire
resistance test. Auto Innovators also agreed, stating that a test
duration of under 10 minutes is insufficient to induce significant
internal heating. Again, Nikola disagreed, stating that the vehicle
testing by Transport Canada
[[Page 104340]]
does not support the exclusion because industry designed its vehicles
to be able to withstand the test. As a result, Nikola said excluding
the requirement from the FMVSS could lead to less safe EV designs.
Agency Response
After reviewing the comments, the agency is not adopting the short
duration fire resistance test. One commenter said that manufacturers
design for the test and the exclusion could reduce safety. However, the
agency does not believe that excluding the test requirement will lead
manufacturers to redesign U.S. vehicles or REESSs in a manner that
reduces the resistance to flame from below. The comments did not
provide any new and supporting data on fire exposure or design. In the
absence of further information demonstrating a safety need, the agency
is not adopting the fire resistance test requirement at this time.
3. Low State of Charge (SOC) Telltale
NPRM Discussion
GTR No. 20 requires a telltale to the driver in the event of low
REESS SOC. The NPRM did not propose the low SOC telltale because NHTSA
believes this requirement is unnecessary because there is no
corresponding low fuel warning requirement for conventional internal
combustion engine vehicles. The NPRM requested comment on whether NHTSA
should adopt the GTR No. 20's low SOC telltale requirement, and if yes,
what the telltale should look like.
Comments Received
All of the comments on the low SOC telltale requirement agreed with
NHTSA's proposal not to require a low SOC telltale. Nissan and Auto
Innovators both stated that regulation is unnecessary because
manufacturers already provide SOC information. HATCI likewise agreed
with the stated rationale. Nikola also agreed with the exclusion, as
``a requirement for low SOC would require standardizing when the light
was to come on [and] it should be left up to the OEM.''
Agency Response
After reviewing the comments, the agency is not adding a low SOC
telltale requirement. The agency believes that all electric-powered
vehicles already provide low SOC telltales due to consumer demand.
Regulation is unnecessary and excluding the low SOC telltale
requirement is appropriate and consistent with not having a low fuel
warning regulatory requirement for conventional internal combustion
engine vehicles.
j. Low-Speed Vehicles
NPRM Discussion
The NPRM requested comments on applying aspects of FMVSS No. 305a
to electric low-speed vehicles that travel under 40 km/h (25 mph) (as
defined in 49 CFR 571.3).\41\ particularly for normal vehicle
operations and safe operation of the REESS. The agency requested
comment on the possible applicability of FMVSS No. 305a to low-speed
vehicles and its relevant safety needs, including any supporting
research on low-speed vehicles.
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\41\ See FMVSS No. 500, ``Low speed vehicles,'' 49 CFR 500.
---------------------------------------------------------------------------
Comments Received
A few commenters addressed the inclusion of low-speed electric
vehicles (LSEVs). NTSB said that LSEVs should be included, as the risks
and potential hazards are well established and because NHTSA's proposed
operational requirements involve appropriate safety planning and no
performance measure or tests, and cited the collision of an autonomous
electric shuttle that occurred in 2017. On the other hand, MEMA said
the standard should not apply to LSEVs. Honeywell stated support
specifically for application of the thermal event warning requirement,
because low-speed vehicles often use the same battery cell types as
cars and are likewise at risk for thermal events.
Agency Response
After reviewing the comments, the agency is not adopting additional
requirements for LSEVs at this time. In general, low-speed vehicles
such as golf carts are not subject to the same requirements as higher-
speed motor vehicles. LSEVs are subject to FMVSS No. 500, ``Low-speed
vehicles,'' which specifies required safety requirements for low-speed
vehicles. While thermal events and other hazards are a concern for any
rechargeable battery system, LSEVs generally have smaller batteries
than higher-speed motor vehicles and are not subject to the same use
conditions. The comments did not provide any supporting research on
low-speed vehicles demonstrating a safety need for additional
requirements. The autonomous shuttle crash cited by NTSB occurred at a
very low speed and did not exhibit any safety hazards from the REESS.
NHTSA will continue to assess electric vehicle safety and the need to
establish additional requirements for LSEVs in the future when
additional data is available.
j. Emergency Response Information
Proposed Requirements
The NPRM proposed to require manufacturers to submit standardized
emergency response information for each vehicle model and model year to
NHTSA's website for public access. The emergency response information
would include the rescue sheet and the emergency response guide (ERG).
The rescue sheets must follow the layout and format in ISO-17840-
1:2022I (for vehicles with a GVWR less than or equal to 4,536 kg
(10,000 lb)) and the format in ISO-17840-2:2019(E) (for vehicles with a
GVWR greater than 4,536 kg (10,000 lb)). The ERGs must follow the
template layout and format of ISO-17840-3:2019(E) and provide in-depth
information linked and aligned to the corresponding rescue sheet to
support the quick and safe action of emergency responders. The NPRM
proposed that electronic versions of the rescue sheets and ERGs for all
vehicles to which FMVSS No. 305a applies must be submitted prior to
certification of the vehicle.
Comments Received
Many commenters expressed support for NHTSA's collection of
standardized emergency response information. Consumer Reports, DTNA,
EMA, Lucid, Nikola, Tesla, Volkswagen, ZETA, CAS, and EV Rescue App
were among the commenters that stated agreement with the proposed
requirements. Firefighter and ISO project leader Kurt Vollmacher also
expressed support for the use of ISO 17840 and for the establishment of
a central database. Some commenters asked for clarification of the
requirements, suggested additional provisions, or requested
modification to the submission timeline.
NTSB expressed strong support for all aspects of the proposed ERG
and rescue sheet submission requirements, stating that NHTSA's proposal
is a better approach than incorporating the information as part of the
New Car Assessment Program, as NTSB originally recommended. NTSB agreed
with hosting the standardized documents on a NHTSA website and
suggested that NHTSA work with NFPA to redirect users to the new source
of information. NTSB also stated that it is important to include the
legacy information from the NFPA website because responders interact
with vehicles from previous model years. Lucid likewise said NHTSA
should include the ERGs from the NFPA site.
HATCI, Auto Innovators, and NFA expressed general support for the
proposed requirements but requested
[[Page 104341]]
clarification. HATCI said, ``it is unclear the method by which the
Agency plans to have manufacturers submit these documents and how the
Agency intends to process the submissions,'' and inquired whether
NHTSA's proposal intends to replace the NFPA's housing of information
or if manufacturers will need to submit the ERGs to multiple locations.
Auto Innovators likewise said NHTSA should provide clear information
and guidance for uploading the information to the NHTSA website to
ensure timeliness and accuracy, and should ``clarify its interpretation
of ISO 17840 as the current standard on which all rescue sheets and
ERGs should be based.'' NFA asked ``whether it would be permissible to
consolidate the Rescue Sheet and ERG into a single document.''
With regard to the submission timeline, Auto Innovators requested
``that NHTSA establish a process to ensure that ERGs are made available
starting on the date when the subject vehicle is first introduced for
sale in the United States . . . to protect final design information.''
Volkswagen also requested submission just prior to market introduction,
to allow the manufacturer to reserve its final design pictures or plans
for press and social media release. Volkswagen said there would be no
added risk to this timeline because the vehicle would not be available
for sale or on public roads during this time.
Other suggestions from Auto Innovators were for NHTSA to establish
a website with a distinct URL for ease of access, increase first
responder awareness of the new resource through safety marketing, and
consider partnerships for mobile and desktop applications as seen with
Euro NCAP. Lucid suggested an additional requirement for ERGs to
provide high-voltage warnings and identify proper personal protective
equipment for dealing with high-voltage systems. Nikola said NHTSA
should have the standardized ERGs submitted to NFPA, because the first
responder industry knows to go to the NFPA website for information.
Agency Response
After reviewing the comments, the agency is adopting the proposed
emergency response information requirements in part 561. Comments were
largely in favor of the requirements, including standardization and
submission of the documentation. The required documents must be
vehicle-specific and conform to the ISO-17840's layout and format,
which are incorporated by reference in part 561. Adoption of the
existing standardization means that vehicle manufacturers, as well as
first and second responders, are already accustomed to the content and
formatting of the ERGs and rescue sheets, and that the documents are
consistent. The standardized color-coded sections in a specific order
will help first and second responders quickly identify pertinent
vehicle-specific rescue information. Both the ERG and the rescue sheet
are required, as the ERG provides relevant, in-depth information for a
variety of potential incidents, while the rescue sheet is a shorter,
simpler document for quick reference. The headings/contents of the
rescue sheet and the ERG information from ISO are aligned with each
other, i.e., the ERG information works as an extension of the related
rescue sheet. Consequently, due to the varying emergent situations that
could occur, the ERG and rescue sheet should be provided as separate
documents for the relevant safety need, consistency, and ease of access
without confusion.
With regard to document submission and processing, the manufacturer
will upload the emergency response documentation to the designated
NHTSA website, https://www.NHTSA.gov/ERG.\42\ The files will be
publicly available and searchable by vehicle make, model, and model
year, as provided at the time of upload. The documents should be
submitted as PDF files per the guidelines provided on the website.
NHTSA will not modify the contents of the documents submitted by the
manufacturer. The manufacturer is responsible for submitting the
correct ERG and rescue sheet files for each vehicle model and model
year, including any subsequent updates or corrections that are needed.
Secure user login will be provided for manufacturers to upload and
manage documents. The ERGs and rescue sheets will be available to the
public for viewing and to download without a login.
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\42\ The website is expected to go online in February 2025.
Instructions for manufacturers regarding login credentials and file
uploads will be provided on the website at a later date.
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Some commenters requested later submission of the emergency
response documents to protect final design information prior to market
introduction without affecting safety. NHTSA agrees that a later
submission date than the proposed certification date is appropriate and
has revised the timeline accordingly. This final rule requires
manufacturers to submit the emergency response guides and rescue sheets
prior to first sale or lease of the subject vehicle model in the United
States.
Commenters requested clarification on the legacy ERGs that are
currently housed in the NFPA website \43\ and whether manufacturers
should be submitting ERGs to multiple locations. NHTSA is coordinating
with NFPA on ERGs currently housed with NFPA to migrate these legacy
documents to the NHTSA specific website. Manufacturers will only need
to submit the ERGs and rescue sheets to the NHTSA specified website
prior to first vehicle sale or lease on the specified compliance date.
NHTSA will socialize the location of the NHTSA website to first and
second responders.
---------------------------------------------------------------------------
\43\ https://www.nfpa.org/education-and-research/emergency-response/emergency-response-guides#aq=%40culture%3D%22en%22&cq=%40taglistingpage%3D%3D(%22EV%20Gu
ides%22)%20%20&numberOfResults=12&sortCriteria=%40title%20ascending.
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k. Documentation Requirements
NPRM Discussion
The NPRM requested comments on whether the proposed emergency
response information requirements would be better placed in a general
agency regulation than in FMVSS No. 305a, given that the documentation
specifications are more akin to a disclosure requirement (disclosing
information to NHTSA and the public) than a performance test or a
consumer safety information requirement. The NPRM also sought comments
on whether the proposed risk mitigation documentation requirements
would be better placed in a general agency regulation. The mechanisms
for enforcing a failure to meet a documentation requirement could
differ depending on whether the requirement is in an FMVSS or not.
Comments Received
Comments on the documentation provisions were mixed. For the
emergency response information, NTSB said that the emergency responder
information requirements are straightforward enough to be included in
this proposed rulemaking and should not be delayed for a separate
regulation. MEMA stated that it agrees with NHTSA's proposed
documentation provisions, with due regard for the protection of
confidential business information that may be contained therein. Auto
Innovators requested that NHTSA consider initiating rulemaking to add a
Class Determination to 49 CFR part 512 for the technical documentation
submissions to be presumptively confidential.
Most manufacturers and manufacturer associations that commented on
this
[[Page 104342]]
topic argued that the documentation should not be included in FMVSS No.
305a. Auto Innovators asserted that the documentation requirements are
not objective standards and that reporting requirements should not be
subject to the same recall and remedy obligations for FMVSS compliance.
They reasoned that documentation does not directly affect safety and
may be subject to change over time. Comments from DTNA, HATCI, EMA,
NFA, and Nikola were similar. DTNA said the documentation requirements
should be moved because the documentation is not associated with the
vehicle meeting the performance requirements or information necessary
to carry out the test procedure. HATCI said, ``Minor or subjective, yet
remediable, inquiries or revision requests and other inconsequential
errors could be inordinately difficult to resolve within the framework
of an FMVSS.''
Agency Response
After reviewing the comments, the agency agrees that the
documentation requirements are better suited to a separate regulation
than inclusion in FMVSS No. 305a. NHTSA regulates motor vehicle safety
under many grants of authority. For example, one such authority is that
NHTSA is authorized by the Vehicle Safety Act to issue FMVSS; a typical
FMVSS specifies minimum performance requirements and may also include
provisions requiring manufacturers to provide consumers safety
information on properly using a safety system or item of equipment.
Another is that the Vehicle Safety Act authorizes NHTSA to require
manufacturers to retain certain records and/or make information
available to NHTSA. Section 30166 of the Vehicle Safety Act provides
NHTSA the ability to request and inspect manufacturer records that are
necessary to enforce the prescribed regulations. NHTSA is also
authorized by delegation to issue regulations to carry out the agency's
duties of ensuring vehicle safety.\44\ Documentation requirements would
be authorized under these authorities.
---------------------------------------------------------------------------
\44\ 49 U.S.C. 322(a). This provision states that the Secretary
of Transportation may prescribe regulations to carry out the duties
and powers of the Secretary. The authority to implement the Vehicle
Safety Act has been delegated to NHTSA.
---------------------------------------------------------------------------
NHTSA is also mindful that the mechanisms for enforcing a failure
to meet a documentation requirement could differ depending on whether
the requirement is in an FMVSS or not. Section 30118 of the Vehicle
Safety Act (49 U.S.C. 30118) provides that whenever the Secretary of
Transportation (NHTSA by delegation) determines that a vehicle does not
comply with an FMVSS, NHTSA (by delegation) must require the vehicle's
manufacturer to notify the owners, purchasers and dealers of the
vehicle or equipment of the noncompliance and remedy the noncompliance.
An exception to the recall requirement in section 30120(h) authorizes
NHTSA to exempt noncompliances from recall provisions based on a
demonstration that the noncompliance is inconsequential to safety. In
the case of a violation of a disclosure requirement in a regulation
other than an FMVSS, the manufacturer could be subject to injunctive
remedies and/or civil penalties,\45\ but would not be subject to a
recall notification and remedy provision described above.
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\45\ See, e.g., 49 U.S.C. 30165.
---------------------------------------------------------------------------
After consideration of the nature of the documentation
specifications and corresponding enforcement mechanisms, this final
rule establishes the technical documentation and emergency response
documentation requirements in part 561, without additional delay. As
proposed, submission of the emergency response information is required
for all subject vehicles, while submission of the other documentation
specified in part 561 is upon request. Requested documentation may be
submitted as Confidential Business Information (CBI) under 49 CFR part
512. NHTSA will follow 49 CFR part 512 confidential submissions
procedures.
Aligned with NHTSA's average record keeping requirements for
regulations, the corresponding documentation requirements are required
to be retained for five years.\46\
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\46\ For example, prior to the final rule published on August
16, 2024 (89 FR 66629), NHTSA's record retention period, under 49
CFR 576, for motor vehicles, child restraint systems, and tires
concerning malfunctions that may be related to motor vehicle safety
under the Safety Act was 5 years.
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l. Compliance Dates
Proposed Requirements
The NPRM proposed a compliance date of two years after the
publication of the final rule for the proposed requirements other than
the emergency response information. The NPRM proposed a compliance date
of one year after the final rule's publication for the proposed
emergency response information submission to NHTSA to assist first and
second responders. The NPRM further proposed that small-volume
manufacturers, final-stage manufacturers, and alterers would be
provided an additional year to comply with each of the requirements.
Optional early compliance would be permitted.
Comments Received
MEMA agreed with the proposed compliance dates, while several other
commenters requested additional time for the technical requirements.
HATCI agreed with the compliance dates for the emergency response
information but requested an additional year for the other requirements
because some proposed provisions deviate from GTR No. 20 and heavy
vehicle manufacturers will be newly subject to electric system
integrity requirements. Auto Innovators also agreed with the one-year
lead time for manufacturers to submit the required emergency response
guides and rescue sheets but requested an additional two years beyond
the proposed compliance date for the other requirements. In other
words, they requested a lead time of 4 years, because substantive
design changes might be required. They supported allowing an additional
year for small-volume manufacturers, final-stage manufacturers, and
alterers. EMA requested a 5-year lead time for heavy vehicles because
heavy duty vehicle manufacturers will need to perform validation
testing and make the appropriate design and production changes.
Bugatti requested a longer lead time for small-volume manufacturers
because ``the proposed lead periods do not allow sufficient time for
the necessary assessments and validation to be conducted properly for
small volume manufacturers and including final-stage manufacturers.''
Bugatti stated that the dates should be aligned with FMVSS No. 127,
``Automatic Emergency Braking Systems for Light Vehicles,'' which has
compliance dates of September 2029 and September 2030, so that multiple
high impact regulations start simultaneously. For FMVSS No. 305a, these
dates would result in lead times of approximately 5 years for large
volume manufacturers and 6 years for small volume and final-stage
manufacturers.
Agency Response
After reviewing the comments, the agency is adopting the proposed
compliance date for the emergency response information requirements in
part 561. The compliance date is one year after publication of this
final rule for all applicable vehicles. NHTSA believes the 1-year
compliance date for this proposed requirement is long enough for
manufacturers to provide the information to NHTSA in the required
format. They are already providing the information voluntarily to the
NFPA. In
[[Page 104343]]
the interest of public safety, the agency would like to provide the
information on NHTSA's website as soon as possible. If manufacturers
provide the information in a year, NHTSA can begin the process of
posting the information shortly thereafter. Commenters agreed with the
proposed compliance date for submission of the emergency response
information to support first and second responders.
In response to the concern raised about proprietary information of
new vehicle designs being made public before first sale or lease, the
final rule submission timeline requires manufacturers to submit the
emergency response guides and rescue sheets prior to first sale or
lease of the subject vehicle model in the United States. In the first
year that compliance with this requirement becomes mandatory, the
compliance date may not coincide with the first sale or lease of a
vehicle model for that year. In this case, the first sale or lease of
the vehicle model on or after the mandatory compliance date is the time
before which the emergency response information for the vehicle model
must be submitted.
This final rule modifies the proposed compliance date of two years
after publication of the final rule for light vehicle requirements,
other than the emergency response information, such that the compliance
date starts on the first September 1 that is at least 2 years after the
final rule publication date to correspond to when a vehicle model year
typically begins, instead of the originally proposed two years after
the final rule publication.
HATCI requested an additional year and Auto Innovators requested an
additional two years to meet the proposed requirements for light
vehicles because some proposed provisions deviated from GTR No. 20.
While the final rule generally adopts the proposed requirements,
changes to the final rule largely align with GTR No. 20, such as the
adoption of documentation for the thermal event warning requirement
instead of a corresponding testing procedure and clarification of the
definition of SOC. These final rule changes reduce the burden for
additional lead time for compliance because of widespread voluntary
compliance with GTR No. 20. Therefore, we believe a compliance date of
the first September 1 that is at least 2 years after the publication of
this final rule is sufficient for manufacturers of light vehicles to
ensure compliance with the final rule.
On the other hand, the agency is extending the compliance date for
heavy vehicle requirements by an additional year from the originally
proposed one year after the publication of the final rule. NHTSA
recognizes that heavy vehicles are not subject to the current FMVSS No.
305, and additional lead time is needed because design changes may be
needed for heavy vehicles. As noted earlier, the changes made in the
final rule better align with GTR No. 20 requirements. However, the
final rule requires vehicle level testing that is optional in GTR No.
20 and requires overcurrent protection of the REESS for heavy vehicles
that is not required in GTR No. 20. NHTSA acknowledges that heavy
vehicle manufacturers may need time to assess fleet performance, review
their risk management procedures, and document their mitigation
strategies since they are newly subject to electric system integrity
requirements. The agency believes a compliance date of the first
September 1 that is at least 3 years after publication of the final
rule is sufficient for applicable heavy vehicles to comply with FMVSS
No. 305a.
Under 49 U.S.C. 30111(d), a standard may not become effective
before the 180th day after the standard is prescribed or later than one
year after it is prescribed, unless NHTSA finds, for good cause shown,
that a different effective date is in the public interest and publishes
a reason for the finding. A phased-in compliance period of two to four
years that also aligns with the normal vehicle design cycle (model
year) is in the public interest because most vehicles will require
upgrades of hardware or software to meet the requirements of this final
rule. To require compliance with this standard outside of the normal
development cycle would significantly increase the cost of the rule
because vehicles cannot easily be made compliant with the requirements
of this final rule outside of the normal vehicle design cycle.
Note that as discussed in the Regulatory Flexibility Act section of
this document, NHTSA is giving small-volume manufacturers, final-stage
manufacturers, and alterers an additional year to comply.\47\ Optional
early compliance is permitted. Additionally, in the interest of public
safety, the effective date of this final rule is 60 days after its
publication to establish the new requirements in the Code of Federal
Regulations and to allow for optional early compliance.
---------------------------------------------------------------------------
\47\ 49 CFR 571.8(b).
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V. Response to Comments on Issues Not Discussed in the NPRM
a. Future Battery Chemistries
Comments Received
MEMA suggested limiting the application of FMVSS No. 305a to
lithium battery vehicles, to better align with GTR No. 20 and avoid
misconceptions regarding other future battery chemistries. Using
Environmental Protection Agency (EPA)'s 40 CFR 86.1840-01 ``Special
test procedures'' as an example, Rivian suggested that NHTSA
incorporate a similar provision into the regulatory text to address new
chemistries, allowing manufacturers to submit alternative test
procedures for NHTSA's review and advanced approval.
Agency Response
The agency believes that limiting the scope of FMVSS No. 305a to
only lithium-ion batteries would not be beneficial to safety. There are
safety risks with any type of propulsion system and any battery
chemistry. While the FMVSS requirements are based on the current state
of technology, they are intentionally chemistry neutral to allow for
future developments. This neutral approach would not limit adoption of
future battery chemistries and not be design restrictive. The emissions
requirements cited by Rivian include additional provisions because
vehicle manufacturers are required to obtain a certificate of
conformity from the EPA. NHTSA's authority and regulation requirements
are different from EPA's. NHTSA is authorized to issue FMVSSs that set
performance requirements for new motor vehicles and items of motor
vehicle equipment (see 49 U.S.C. Chapter 301). NHTSA does not provide
approval of motor vehicles or motor vehicle equipment, and NHTSA does
not determine compliance of a vehicle or item of motor vehicle
equipment outside the context of an actual enforcement proceeding.
Instead, manufacturers are required to self-certify that their products
conform to all applicable safety standards that are in effect on the
date of manufacture. FMVSS No. 305a does not specify or prohibit
certain battery chemistries. Overall, NHTSA will continue to monitor
the state of REESS technology and associated safety risks, and FMVSS
requirements may be added or modified over time as REESS technology
evolves.
b. Marking and Labeling
Comments Received
The Center for Auto Safety suggested NHTSA to establish and require
[[Page 104344]]
distinctive marking in REESS-equipped vehicles to identify REESS-
associated electrical shock hazards, electrical isolation points and
mechanisms, and related design features by means of standardized,
permanently affixed labels for reference by emergency personnel and
consumers. Similarly, Consumer Reports suggested adding requirements
for hazard warning labels aimed at consumers and maintenance
technicians.
Agency Response
The NPRM did not propose additional requirements for specific,
standardized markings or labeling of electric vehicles, and they are
not in scope for this final rule. FMVSS No. 305, S5.4.1.1 currently
requires high voltage cables to have an orange-colored outer covering
and electric energy storage devices and electrical protection barriers
to have a specific black and yellow high voltage marking. This final
rule adopts these same high voltage identification requirements into
FMVSS No. 305a, S6.1.1. In general, major maintenance and repair of
electric vehicles is conducted by trained personnel at a manufacturer
approved dealership; consumers are advised not to attempt modification
or repair of high voltage systems. Emergency response personnel use
vehicle documentation to help locate specific components, avoid
electric shock hazards, and handle the vehicles safely. This final rule
requires manufacturers to provide standardized ERGs and rescue sheets
to NHTSA to create a centralized location for public access. In
addition, some states already require specific license plates or other
markings on the exterior of alternative fuel vehicles. NHTSA will
continue to evaluate the type, location, and effectiveness of exterior
markings that would further aid first and second responders and support
general emergency mitigation.
c. Test Laboratories
Comment Received
A2LA suggested adopting conformity assessment activities such as
requiring manufacturers to use ISO/IEC 17025 accredited testing
laboratories.
Agency Response
As discussed above, NHTSA does not specify manufacturer development
methods or test facility certifications. NHTSA does not provide
approval of motor vehicles or motor vehicle equipment, and NHTSA does
not determine compliance of a vehicle or item of motor vehicle
equipment outside the context of an actual enforcement proceeding.
Instead, manufacturers are required to self-certify that their products
conform to all applicable safety standards that are in effect on the
date of manufacture.
d. Other Electrical Specifications
Comments Received
EMA suggested adding definitions to S4 for ``Tested-Device,''
``Nominal voltage,'' and ``Suitable Lamp.'' EMA also requested changing
``working voltage'' to ``nominal voltage'' in S7.1.2. For the loss of
electrical isolation warning in S6.4, EMA suggested adding a 1-minute
time limit for activation of the visual warning. EMA also requested
removing the minimum voltage supply for the optional lamp in the
physical barrier tests, as most vehicles have a standard voltage of 12
or 24 volts. EMA also said that S7.1 specified the voltmeter internal
resistance be at least 10 MW and that it should be changed to 10
M[Omega], and that ``chamber'' should be corrected to ``chamfer'' in
figure 7b. For high voltage sources excluded from electrical isolation
requirements, MEMA recommended harmonization with UNECE R100 to clarify
that the 60VDC threshold also applies to pulsating DC voltages less
than 60VDC in cases where there is no change in polarity.
Agency Response
NHTSA appreciates the commenters' review of the regulatory text and
recommended updates. NHTSA's response to each issue raised is as
follows:
1. Definition of Tested-Device: EMA requested allowing component-
level testing and defining ``Tested-Device.' This final rule does not
use the term ``Tested-Device,'' because all tests are conducted at the
full vehicle level and there are no component level tests in FMVSS No.
305a. The April 2024 NPRM used the definition for SOC that is in GTR
No. 20, which refers to the charge of the ``tested device.'' However,
in response to comments received, the SOC definition has been revised
and now refers to the ``REESS'' instead of the ``tested device.''
2. Definition of Suitable Lamp: S7.3.1 of FMVSS No. 305a describes
the test procedure for evaluating protection from direct contact with
high voltage sources. S7.3.1(c) specifies that a ``suitable lamp'' in
series with a low voltage supply of 40-50 volts may be connected
between the access probe (IPXXB or IPXXD) and any high voltage live
parts inside the electrical protection barrier to indicate whether high
voltage live parts were contacted. EMA recommended defining ``suitable
lamp'' to mean ``a circuit tester with an input voltage range of 50 VDC
minimum, that is one of the following types: an incandescent lamp, LED
indicator, buzzer, or Voltmeter.'' EMA stated that the specification
for the voltage supply should be changed such that the vehicle's own
voltage of 12 or 24 volts could be used for the indicator lamp. The
commenter's definition does not specify an upper limit for the voltage
and seemingly contradicts its request to allow use of the vehicle's own
power supply. The voltage range of 40-50 volts is specified in
S7.3.1(c) to ensure sufficient current in the circuit that can be
detected by the lamp, while also ensuring the current is not
sufficiently high to pose a safety risk to testing personnel. The
purpose of the lamp is merely to provide a quick visual indication of
contact with high voltage sources. The agency believes that as long as
a lamp compatible with the voltage supply of 40-50 volts is used, there
is no need to specify the type of lamp. The regulatory text in FMVSS
No. 305a S7.3 was adopted from S9 in FMVSS No. 305, which has been
effective since 2017, and is the same as that in GTR No. 20 and UNECE
R100. The agency will further assess EMA's recommendations regarding
the test procedure for direct contact protection and will consider
updates to the regulatory text later, if warranted. At this time, NHTSA
is adopting the test procedure for direct contact protection currently
in FMVSS No. 305 and proposed in the NPRM for inclusion in FMVSS No.
305a.
3. Definition and Use of Nominal Voltage: EMA requested defining
and using the term ``nominal voltage,'' instead of ``working voltage,''
for determining voltage in S7.1.2 of FMVSS No. 305a. EMA provided a
definition of ``nominal voltage'' to mean a value that represents the
typical or midpoint of a battery's maximum operating voltage and the
minimum operating voltage over its charge and discharge cycle. NHTSA is
not making this requested change in the final rule. The agency notes
that the term ``working voltage'' and method of determining voltage are
adopted from FMVSS No. 305 and have been effective since 2010. We
believe the term ``working voltage'' is appropriate because it
evaluates whether a component in the electric power train is a high
voltage source when the vehicle is fully charged. Additionally, the
singular instance of ``nominal voltage'' in S12.2 of the NPRM
regulatory text has been changed to ``working voltage'' for
consistency.
4. Time limit for activating warning alerting driver to loss of
electrical
[[Page 104345]]
isolation: For the loss of electrical isolation warning in S6.4, EMA
suggested adding a time limit: ``The maximum time allowed to activate
visual warning lamp shall be [less than] 1 minute when tested per
S7.4.'' NHTSA did not include a time limit for the warning to activate
when there is a loss in electrical isolation, which is consistent with
other warning requirements in FMVSSs, e.g., the seat belt warning in
FMVSS No. 208, ``Occupant crash protection.'' Activation of the warning
is assessed visually by test personnel when loss in electrical
isolation is simulated in accordance with S7.4.
5. Typographical Error in figure 7b: EMA requested changing the
phrase, ``chamber all edges,'' to ``chamfer all edges,'' in figure 7b.
Jointed Test Finger IPXXB, of the regulatory text. This final rule
corrects the typographical error in figure 7b.
6. Voltmeter resistance in S7.1 of FMVSS No. 305a: EMA noted that
the proposed S7.1 of FMVSS No. 305a specifies the voltmeter internal
resistance be at least 10 MW and that it should be changed to 10
M[Omega]. The regulatory text in the April 2024 NPRM correctly
specifies the voltmeter resistance in M[Omega] and so no change is made
in the final rule regulatory text.
7. Exclusion of certain high voltage sources from electrical
isolation requirements: MEMA requested clarifying that the exclusion in
S6.3.2 also applies to pulsating DC voltages of less than 60 VDC in
cases where there is no change in polarity. The September 2017 final
rule \48\ updating FMVSS No. 305 excluded 48 V systems that are
connected to the electrical chassis from electrical isolation
requirements. In 48 V systems, the AC-DC inverter converts the DC
current from the 48 V battery into AC for the 3-phase AC motor. The
voltage between the electrical chassis and each of the phases of the AC
electric motor is switched DC voltage (voltage between 0 and 48 volts).
Because that voltage is less than 60 volts, it is considered low DC
voltage under FMVSS No. 305. However, the voltage between two phases of
the AC motor is AC, and may be slightly greater than 30 VAC under
certain circumstances, which can be considered a high voltage AC source
under the standard. However, the physical barrier protection (both
direct and indirect contact protection) around the AC motor, and around
cables from the inverter to the motor, would mitigate human contact
with these AC high voltage sources, and thereby mitigate the likelihood
of electric shock. In the 21st meeting of the working group developing
GTR No. 20 Phase 2, the European Association of Automotive Suppliers
(CLEPA) provided a rationale \49\ for also excluding pulsating DC high
voltage sources with working voltage of 60 VDC or less where there is
no change in polarity from electrical isolation requirements so as to
accommodate 48 V air-cooled motor generators in the electric power
train. NHTSA agrees with this rationale for this exclusion of pulsating
DC high voltage sources with no change in polarity and with working
voltage of 60 VDC or less from the electrical isolation requirements of
S6.3.1 of FMVSS No. 305a.\50\ The regulatory text has been modified to
provide this clarification.
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\48\ 82 FR 44945 (Sept. 27, 2017).
\49\ See https://wiki.unece.org/download/attachments/117508721/EVS21-K01%20%5BCLEPA%5DR100-3%2048V%20Issue.pptx?api=v2.
\50\ Section 5.3.4.1 of IEC TS 60479-2, ``Effects of current on
human beings and livestock--Part 2,'' available at https://webstore.iec.ch/publication/63392, states that for combination of DC
and AC voltage sources where there is no change in polarity, half
the peak voltage can be used for determining electric shock risk.
Because the risk of electric shock for 30 VAC is the same as 60 VDC,
pulsating DC voltages less than or equal to 60 VDC pose no
additional risk and can also be excluded from the electrical
isolation requirement. The direct and indirect contact protection
requirements further mitigate the risk of electric shock.
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e. Static Rollover
Comments Received
Tesla requested that NHTSA reconsider the static rollover test
requirement, given the current state of EV batteries compared to older
lead-acid batteries.
Agency Response
The agency believes that there is merit in the static rollover test
requirement, consistent with other FMVSS requirements. In addition, the
agency is retaining requirements pertaining to electrolyte leakage for
REESS with liquid electrolyte.
VI. Rulemaking Analyses and Notices
Executive Order 12866, Executive Order 14094, Executive Order 13563,
and DOT Order Regulatory Policies and Procedures
NHTSA has considered the impact of this rulemaking action under
Executive Orders 12866, 14094, and 13563, DOT Order 2100.6A and the
Department of Transportation's regulatory policies and procedures. The
final rule is not considered to be significant under the Department of
Transportation's regulatory policies and procedures. 44 FR 11034 (Feb.
26, 1979). This action was not reviewed by the Office of Management and
Budget under E.O. 12866.
This final rule issues FMVSS No. 305a and Part 561 to update and
expand the requirements that are in FMVSS No. 305. Most of GTR No. 20
has already been adopted into FMVSS No. 305; this final rule completes
the process by expanding FMVSS No. 305's applicability to heavy
vehicles and by adopting the GTR's requirements for the REESS. Because
there is widespread conformance with the requirements that would apply
to existing vehicles, we anticipate no costs or benefits associated
with this rulemaking.
This final rule also requires that electric vehicle manufacturers
submit standardized emergency response information to a NHTSA central
depository, to assist first and second responders. A comprehensive list
of pertinent vehicle-specific rescue information at a central location
will enable first and second responders to respond to emergencies as
quickly and safely as possible. Currently, electric vehicle
manufacturers voluntarily upload emergency response information to the
National Fire Protection Association's training site, so manufacturers
are already providing vehicle-specific emergency response information.
Under Part 561, manufacturers will submit ERGs and rescue sheets to
NHTSA instead. We anticipate no additional costs by the manufacturers.
Regulatory Flexibility Act
The Regulatory Flexibility Act of 1980 (5 U.S.C. 601 et seq.)
(``the Act'') requires agencies to evaluate the potential effects of
their proposed and final rules on small businesses, small
organizations, and small Government jurisdictions. The Small Business
Administration's regulations at 13 CFR part 121 define a small
business, in part, as a business entity ``which operates primarily
within the United States.'' (13 CFR 121.105(a)).
The Act requires agencies to prepare and make available an initial
and final regulatory flexibility analysis (RFA) describing the impact
of proposed and final rules on small entities. An RFA is not required
if the head of the agency certifies that the proposed or final rule
will not have a significant impact on a substantial number of small
entities. The head of the agency has made such a certification with
regard to this final rule.
The factual basis for the certification (5 U.S.C. 605(b)) is set
forth below. Although the agency is not required to issue an initial
regulatory flexibility analysis, this section discusses many of
[[Page 104346]]
the issues that an initial regulatory flexibility analysis would
address.
Section 603(b) of the Act specifies the content of an RFA. Each RFA
must contain:
1. A description of the reasons why action by the agency is being
considered;
2. A succinct statement of the objectives of, and legal basis for,
a final rule;
3. A description of and, where feasible, an estimate of the number
of small entities to which the final rule will apply;
4. A description of the projected reporting, recording keeping and
other compliance requirements of a final rule, including an estimate of
the classes of small entities that will be subject to the requirement
and the type of professional skills necessary for preparation of the
report or record;
5. An identification, to the extent practicable, of all relevant
Federal rules which may duplicate, overlap or conflict with the final
rule;
6. Each final regulatory flexibility analysis shall also contain a
description of any significant alternatives to the final rule which
accomplish the stated objectives of applicable statutes and which
minimize any significant economic impact of the final rule on small
entities.
A description of the reason why action by the agency is being
considered and the objectives of, and legal basis for, the final rule
are discussed at length earlier in this document.
This final rule will directly affect manufacturers subject to FMVSS
No. 305a and Part 561. The Small Business Administration's size
standard regulation at 13 CFR part 121, ``Small business size
regulations,'' prescribes small business size standards by North
American Industry Classification System (NAICS) codes. NAICS code
336211, Motor Vehicle Body Manufacturing, prescribes a small business
size standard of 1,000 or fewer employees. NAICS code 336390, Other
Motor Vehicle Parts Manufacturing, prescribes a small business size
standard of 1,000 or fewer employees. Most motor vehicle manufacturers
would not qualify as a small business.
NHTSA is aware of 3 small manufacturers of light and heavy electric
vehicles. NHTSA believes that this rule will not have a significant
economic impact on these manufacturers for the following reasons.
First, small manufacturers of light electric vehicles are already
subject to the electric vehicle safety requirements of FMVSS No. 305
and have been certifying compliance to the standard for years. They are
familiar with FMVSS requirements for electric vehicle safety, know how
to assess the conformance of their vehicles with the requirements, and
know how to certify their vehicles to the FMVSS. The new requirements
for the REESS are manageable because the overcharge, over-discharge,
over-current, over-temperature, and external short-circuit tests are
non-destructive tests and can be conducted in serial order. The
documentation requirements for safety risk mitigation associated with
charging and discharging during cold temperature, safety risk
mitigation associated with an internal short circuit in a single cell
of a REESS, warning for a thermal event, and warning in the event of a
malfunction of the vehicle controls that manage REESS safe operation
are not design restrictive and add minimal cost. The documentation
requirements simply ask manufacturers to describe to NHTSA how they
have assessed certain safety risks and mitigated them.
Second, there already is widespread voluntary compliance by the
manufacturers with GTR No. 20, which is also aligned with industry
standards. Therefore, there will be only a minor economic impact.
Finally, although the final certification would be made by the
manufacturer, this final rule allows one additional year for small
volume manufacturers, final-stage manufacturers, and alterers to
comply. This approach is similar to the approach NHTSA has taken in
other rulemakings in recognition of manufacturing differences between
larger and smaller manufacturers. NHTSA anticipates that EV components
meeting FMVSS No. 305a will be developed by vehicle designers and
suppliers and integrated into the fleets of larger vehicle
manufacturers first, before small manufacturers. This final rule
provides smaller manufacturers flexibility, so they have time to obtain
the equipment and work with the suppliers after the demands of the
larger manufacturers are met.
This final rule applies to heavy vehicles, so this NPRM would also
affect manufacturers of vehicles of over 4,536 kg (10,000 lb) GVWR,
some of which may be final-stage manufacturers.\51\ According to the
U.S. Census, there are 570 small businesses in body manufacturing for
light, medium, and heavy-duty classes. However, it is NHTSA's
understanding that these small entities rarely make modifications to a
vehicle's REESS system and instead rely upon the pass-through
certification provided by the first-stage manufacturer, which is not
typically a small business. The same is true for alterers, which are
manufacturers that obtain and alter a complete vehicle prior to the
vehicle's first sale to a consumer.\52\ Furthermore, even if the final-
stage manufacturer or alterer must make the certification
independently, as explained above this certification responsibility is
manageable. The requirements do not involve crash testing (except for
heavy school buses, as discussed below), and conformance with the
requirements can be assessed relatively simply in a laboratory setting.
And finally, this rule further accommodates final-stage manufacturers
and alterers by providing them an additional year before compliance is
required.\53\ For the reasons above, NHTSA does not believe that the
economic impacts on small entities will be significant.
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\51\ Final-stage manufacturers produce vehicles by obtaining an
incomplete vehicle (comprising the chassis and other associated
parts) manufactured by an incomplete vehicle manufacturer, which is
typically a large manufacturer. The final-stage manufacturer
produces a vehicle by installing the vehicle body on the incomplete
vehicle. The final-stage manufacturer typically certifies a complete
vehicle by staying within manufacturing instructions provided by the
incomplete vehicle manufacturer.
\52\ Alterers certify that the vehicle was altered by them and
as altered conforms to all applicable FMVSS, bumper, and theft
prevention standards affected by the alteration.
\53\ See 49 CFR 571.8(b).
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With regard to the crash test requirement for small manufacturers
of heavy school buses, the additional requirement is for heavy school
buses with high voltage electric propulsion systems to meet post-crash
electrical safety requirements when impacted by the moving contoured
barrier specified in FMVSS No. 301. This requirement does not require
additional crash testing and aligns the applicability of FMVSS No. 305a
with those of FMVSS Nos. 301 and 303. Per FMVSS No. 301 and FMVSS No.
303, heavy school buses (school buses with a GVWR greater than 4,536
kg) using conventional fuel or compressed natural gas for propulsion
are required to maintain fuel system integrity in a crash test where
the moving contoured barrier specified in FMVSS No. 301 traveling at
any speed up to 48 km/h impacts the school bus at any point and angle.
These requirements ensure post-crash safety to maintain the current
high safety standards for school buses. Finally, this rule accommodates
small manufacturers and final stage manufacturers of heavy school buses
by providing them an additional year before compliance is required. For
the reasons above, NHTSA
[[Page 104347]]
does not believe that the economic impacts of this rule on small
entities will be significant.
National Environmental Policy Act
NHTSA has analyzed this rule for the purposes of the National
Environmental Policy Act. In accordance with 49 CFR 1.81, 42 U.S.C.
4336, and DOT NEPA Order 5610.1C, NHTSA has determined that this rule
is categorically excluded pursuant to 23 CFR 771.118(c)(4) (planning
and administrative activities, such as promulgation of rules, that do
not involve or lead directly to construction). This rulemaking, which
establishes Federal Motor Vehicle Safety Standard (FMVSS) No. 305a,
``Electric-powered vehicles: Electrolyte spillage and electrical shock
protection,'' to update and replace FMVSS No.305 and to include
performance requirements for propulsion batteries for light and heavy
vehicles, and which establishes a new regulation, Part 561,
``Documentation for Electric-powered Vehicles,'' that requires
manufactures to compile risk mitigation documentation and submit
standardized emergency response information to assist first and second
responders handling electric vehicles, is not anticipated to result in
any environmental impacts, and there are no extraordinary circumstances
present in connection with this rulemaking.
Executive Order 13132 (Federalism)
NHTSA has examined this rule pursuant to Executive Order 13132 (64
FR 43255; Aug. 10, 1999) and concluded that no additional consultation
with States, local governments, or their representatives is mandated
beyond the rulemaking process. The agency has concluded that the rule
does not have sufficient federalism implications to warrant
consultation with State and local officials or the preparation of a
federalism summary impact statement. The rule does not have
``substantial direct effects on the States, on the relationship between
the national government and the States, or on the distribution of power
and responsibilities among the various levels of government.''
NHTSA rules can have preemptive effect in two ways. First, the
National Traffic and Motor Vehicle Safety Act contains an express
preemption provision: When a motor vehicle safety standard is in effect
under this chapter, a State or a political subdivision of a State may
prescribe or continue in effect a standard applicable to the same
aspect of performance of a motor vehicle or motor vehicle equipment
only if the standard is identical to the standard prescribed under this
chapter. 49 U.S.C. 30103(b)(1). It is this statutory command that
preempts any non-identical State legislative and administrative law
address the same aspect of performance. The express preemption
provision described above is subject to a savings clause under which
``[c]ompliance with a motor vehicle safety standard prescribed under
this chapter does not exempt a person from liability at common law.''
49 U.S.C. 30103(e). Pursuant to this provision, State common law tort
causes of action against motor vehicle manufacturers that might
otherwise be preempted by the express preemption provision are
generally preserved.
NHTSA rules can also preempt State law if complying with the FMVSS
would render the motor vehicle manufacturers liable under State tort
law. Because most NHTSA standards established by an FMVSS are minimum
standards, a State common law tort cause of action that seeks to impose
a higher standard on motor vehicle manufacturers will generally not be
preempted. However, if and when such a conflict does exist--for
example, when the standard at issue is both a minimum and a maximum
standard--the State common law tort cause of action is impliedly
preempted. See Geier v. American Honda Motor Co., 529 U.S. 861 (2000).
Pursuant to Executive Order 13132, NHTSA has considered whether
this rule could or should preempt State common law causes of action.
The agency's ability to announce its conclusion regarding the
preemptive effect of one of its rules reduces the likelihood that
preemption will be an issue in any subsequent tort litigation. To this
end, the agency has examined the nature (e.g., the language and
structure of the regulatory text) and objectives of this rule and finds
this rule, like many NHTSA rules, would prescribe only a minimum safety
standard. As such, NHTSA does not intend that this rule preempt state
tort law that would effectively impose a higher standard on motor
vehicle manufacturers than that established by this rule. Establishment
of a higher standard by means of State tort law would not conflict with
the standards in this final rule. Without any conflict, there could not
be any implied preemption of a State common law tort cause of action.
Executive Order 12988 (Civil Justice Reform)
With respect to the review of the promulgation of a new regulation,
section 3(b) of Executive Order 12988, ``Civil Justice Reform'' (61 FR
4729, Feb. 7, 1996), requires that Executive agencies make every
reasonable effort to ensure that the regulation: (1) Clearly specifies
the preemptive effect; (2) clearly specifies the effect on existing
Federal law or regulation; (3) provides a clear legal standard for
affected conduct, while promoting simplification and burden reduction;
(4) clearly specifies the retroactive effect, if any; (5) adequately
defines key terms; and (6) addresses other important issues affecting
clarity and general draftsmanship under any guidelines issued by the
Attorney General. This document is consistent with that requirement.
Pursuant to this Order, NHTSA notes as follows. The issue of
preemption is discussed above. NHTSA notes further that there is no
requirement that individuals submit a petition for reconsideration or
pursue other administrative proceedings before they may file suit in
court.
Executive Order 13045 (Protection of Children From Environmental Health
and Safety Risk)
Executive Order 13045 (62 FR 19885, April 23, 1997) applies to any
rule that: (1) is determined to be ``economically significant'' as
defined under E.O. 12866, and (2) concerns an environmental, health, or
safety risk that NHTSA has reason to believe may have a
disproportionate effect on children. If the regulatory action meets
both criteria, we must evaluate the environmental health or safety
effects of the planned rule on children and explain why the planned
regulation is preferable to other potentially effective and reasonably
feasible alternatives considered by us.
This final rule is not subject to the Executive order because it is
not economically significant as defined in E.O. 12866.
Privacy Act
Please note that anyone is able to search the electronic form of
all comments received into any of our dockets by the name of the
individual submitting the comment (or signing the comment, if submitted
on behalf of an association, business, labor union, etc.). You may
review DOT's complete Privacy Act Statement in the Federal Register
published on April 11, 2000 (65 FR 19477-78), or online at http://www.dot.gov/privacy.html.
Congressional Review Act
The Congressional Review Act, 5 U.S.C. 801 et. seq., as added by
the Small Business Regulatory Enforcement Fairness Act of 1996,
generally provides that before a rule may take effect, the
[[Page 104348]]
agency promulgating the rule must submit a rule report, which includes
a copy of the rule, to each House of the Congress and to the
Comptroller General of the United States. NHTSA will submit a report
containing this rule and other required information to the U.S. Senate,
the U.S. House of Representatives, and the Comptroller General of the
United States prior to publication of the rule in the Federal Register.
This rule does not meet the criteria in 5 U.S.C. 804(2) to be
considered a major rule. The rule will be effective sixty days after
the date of publication in the Federal Register.
Paperwork Reduction Act
Under the procedures established by the Paperwork Reduction Act of
1995 (PRA) (44 U.S.C. 3501, et. seq.), Federal agencies must obtain
approval from the OMB for each collection of information they conduct,
sponsor, or require through regulations. A person is not required to
respond to a collection of information by a Federal agency unless the
collection displays a valid OMB control number. The Information
Collection Request (ICR) for the new information collection described
below has been forwarded to OMB for review and comment.
The final rule has two types of new collection of information that
are part of the Part 561 requirements: (1) Electric Vehicles: Rescue
Sheets and Emergency Response Guides and (2) Electric Vehicles: REESS
Thermal Propagation Safety Risk Analysis and Mitigation Documentation.
NHTSA sought comment on the new information collection requirements in
the NPRM published on April 15, 2024.\54\ There were no PRA-specific
comments provided. NHTSA's response to the comments and the final
rule's information collection requirements are discussed in sections
IV.j-l above. As discussed, NHTSA is largely adopting the proposal with
some changes. In accordance with the requirements of the PRA, NHTSA is
resubmitting the ICR for this final rule. In the final rule, the
emergency response information and four documentation requirements are
added to the general regulation Part 561 rather than in the proposed
FMVSS No. 305a, given that the documentation specifications are more
akin to a disclosure requirement than a performance test. The estimated
total burden of this collection is modified to account for the final
rule's addition of the audio-visual warning for a thermal event in the
REESS to be part of the documentation requirements that was not
initially proposed in the NPRM. For each vehicle model, vehicle
manufacturers will need an estimated 84 hours to complete the four
documentation requirements (17 hours to complete the documentation for
low temperature operation safety, 17 hours for the documentation about
warning in the event of operational failure of REESS vehicle controls,
17 hours for the documentation for thermal event warning, and 33 hours
for the documentation covering thermal runaway due to internal short in
a single cell of the REESS). After this rule's effective date, all 205
vehicle models are expected to compile the necessary information to
meet the four documentation requirements. The total estimated annual
burden hours for the four documentation requirements is 17,220 hours
(205 vehicle models x 84 hours). The previous total estimated burden
hours for the three documentation requirements in the NPRM was 13,735
hours (205 vehicle models x 67 hours).
---------------------------------------------------------------------------
\54\ 89 FR 26704.
---------------------------------------------------------------------------
The estimated total annual burden hours for the emergency response
information was slightly decreased to approximately 2,335 hours from
the original estimation of 2,506 burden hours. Because rescue sheets
and emergency response guides often cover several model years, the
percentage of models that would need new or updates to existing or
previously submitted rescue sheets and ERGs is likely to decrease after
the second year of the effective date. With additional documentation
requirements from the final rule, the total estimated annual burden
hours for the two new types of information collection is estimated to
be 19,565 burden hours.
In the NPRM, NHTSA originally included labor costs under the burden
cost calculation. NHTSA now estimates that there will be no costs to
respondents other than the labor costs from the corresponding burden
hours of compiling the information. Therefore, the total annual burden
cost has now been corrected to be $0.
The OMB control numbers for NHTSA regulations are displayed at 49
CFR part 509. When OMB approves this ICR, the agency will announce that
approval in the Federal Register and, as appropriate, display the OMB
control number on the applicable collection instruments and publish a
technical amendment to 49 CFR part 509 to display the OMB control
number for the approved information collection activities contained in
this final rule.
National Technology Transfer and Advancement Act
Section 12(d) of the National Technology Transfer and Advancement
Act of 1995 (NTTAA), Public Law 104-113, as amended by Public Law 107-
107 (15 U.S.C. 272), directs the agency to evaluate and use voluntary
consensus standards in its regulatory activities unless doing so would
be inconsistent with applicable law or is otherwise impractical.
Voluntary consensus standards are technical standards (e.g., materials
specifications, test methods, sampling procedures, and business
practices) that are developed or adopted by voluntary consensus
standards bodies, such as the Society of Automotive Engineers (SAE).
The NTTAA directs us to provide Congress (through OMB) with
explanations when the agency decides not to use available and
potentially applicable voluntary consensus standards.
This final rule is consistent with the goals of the NTTAA. This
rule adopts a global consensus standard. The GTR was developed by a
global regulatory body and is designed to increase global harmonization
of differing vehicle standards. The GTR leverages the expertise of
governments in developing a vehicle standard to increase electric
vehicle safety, including the performance of the REESS. NHTSA's
consideration of GTR No. 20 accords with the principles of NTTAA as
NHTSA's consideration of an established, proven global technical
regulation has reduced the need for NHTSA to expend significant agency
resources on the same safety need addressed by GTR No. 20.
In addition, the following voluntary consensus standards have been
used in developing this final rule:
ISO-6469-1: Amendment 1 2022-11.
ISO-26262:2018.
ISO 17840-1:2022(E), ``Road vehicles--Information for
first and second responders--Part 1: Rescue sheet for passenger cars
and light commercial vehicles,'' Second Edition, February 2022.
ISO 17840-2:2019(E), ``Road vehicles--Information for
first and second responders--Part 2: Rescue sheet for buses, coaches
and heavy commercial vehicles,'' First edition, April 201.
ISO 17840-3:2019(E), ``Road vehicles--Information for
first and second responders--Part 3: Emergency response guide
template,'' First Edition, April 2019.
[[Page 104349]]
Unfunded Mandates Reform Act
Section 202 of the Unfunded Mandates Reform Act of 1995 (UMRA),
Public Law 104-4, requires Federal agencies to prepare a written
assessment of the costs, benefits, and other effects of proposed or
final rules that include a Federal mandate likely to result in the
expenditure by State, local, or Tribal governments, in the aggregate,
or by the private sector, of more than $100 million annually (adjusted
for inflation with base year of 1995). Adjusting this amount by the
implicit gross domestic product price deflator for the year 2022
results in $177 million (111.416/75.324 = 1.48). This rule will not
result in a cost of $177 million or more to State, local, or Tribal
governments, in the aggregate, or the private sector. Thus, this rule
is not subject to the requirements of sections 202 of the UMRA.
Executive Order 13609 (Promoting Regulatory Cooperation)
The policy statement in section 1 of Executive Order 13609
provides, in part: The regulatory approaches taken by foreign
governments may differ from those taken by U.S. regulatory agencies to
address similar issues. In some cases, the differences between the
regulatory approaches of U.S. agencies and those of their foreign
counterparts might not be necessary and might impair the ability of
American businesses to export and compete internationally. In meeting
shared challenges involving health, safety, labor, security,
environmental, and other issues, international regulatory cooperation
can identify approaches that are at least as protective as those that
are or would be adopted in the absence of such cooperation.
International regulatory cooperation can also reduce, eliminate, or
prevent unnecessary differences in regulatory requirements.
The agency participated in the development of GTR No. 20 to
harmonize the standards of electric vehicles. As a signatory member,
NHTSA is incorporating electrical safety requirements and options
specified in GTR No. 20 with modifications into FMVSS No. 305a and Part
561.
Incorporation by Reference
Under regulations issued by the Office of the Federal Register (1
CFR 51.5(a)), an agency must summarize in the preamble of a proposed or
final rule the material it incorporates by reference and discuss the
ways the material is reasonably available to interested parties or how
the agency worked to make materials available to interested parties.
In this final rule, NHTSA incorporates by reference three documents
into the Code of Federal Regulations. The first document is ISO 17840-
1:2022(E), ``Road vehicles--Information for first and second
responders--Part 1: Rescue sheet for passenger cars and light
commercial vehicles.'' ISO 17840-1:2022(E) standardizes the content and
layout of rescue sheets for passenger cars and light commercial
vehicles.
The second document is ISO 17840-2:2019(E), ``Road vehicles--
Information for first and second responders--Part 2: Rescue sheet for
buses, coaches and heavy commercial vehicles.'' ISO 17840-2:2019(E)
standardizes the rescue sheets for buses, coaches, and heavy commercial
vehicles.
The third document is ISO 17840-3:2019(E), ``Road vehicles--
Information for first and second responders--Part 3: Emergency response
guide template.'' ISO 17840-3:2019(E) establishes a template and
defines the general content for manufacturers' emergency response
guides for all vehicle types.
All three documents are incorporated by reference solely to specify
the layout and format of the rescue sheets and emergency response
guides. The ISO material is available for review at NHTSA and is
available for purchase from ISO.\55\
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\55\ ISO standards may be purchased from the ANSI webstore
https://webstore.ansi.org/.
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Severability
The issue of severability of FMVSSs is addressed in 49 CFR 571.9.
It provides that if any FMVSS or its application to any person or
circumstance is held invalid, the remainder of the part and the
application of that standard to other persons or circumstances is
unaffected.
Regulation Identifier Number
The Department of Transportation assigns a regulation identifier
number (RIN) to each regulatory action listed in the Unified Agenda of
Federal Regulations. The Regulatory Information Service Center
publishes the Unified Agenda in April and October of each year. You may
use the RIN contained in the heading at the beginning of this document
to find this action in the Unified Agenda.
Rulemaking Summary, 5 U.S.C. 553(b)(4)
As required by 5 U.S.C. 553(b)(4), a summary of this rule can be
found in the Abstract section of the Department's Unified Agenda entry
for this rulemaking at https://www.reginfo.gov/public/do/eAgendaViewRule?pubId=202304&RIN=2127-AM43.
Plain Language
Executive Order 12866 requires each agency to write all rules in
plain language. Application of the principles of plain language
includes consideration of the following questions:
Have we organized the material to suit the public's needs?
Are the requirements in the rule clearly stated?
Does the rule contain technical language or jargon that
isn't clear?
Would a different format (grouping and order of sections,
use of headings, paragraphing) make the rule easier to understand?
Would more (but shorter) sections be better?
Could we improve clarity by adding tables, lists, or
diagrams?
What else could we do to make the rule easier to
understand?
If you have any responses to these questions, please write to us
with your views.
Submission of Confidential Information
You should submit a redacted ``public version'' of your comment
(including redacted versions of any additional documents or
attachments). This ``public version'' of your comment should contain
only the portions for which no claim of confidential treatment is made
and from which those portions for which confidential treatment is
claimed has been redacted. See below for further instructions on how to
do this.
You also need to submit a request for confidential treatment
directly to the Office of Chief Counsel. Requests for confidential
treatment are governed by 49 CFR part 512. Your request must set forth
the information specified in part 512. This information includes the
materials for which confidentiality is being requested (as explained in
more detail below); supporting information, pursuant to Sec. 512.8;
and a certificate, pursuant to Sec. 512.4(b) and part 512, appendix A.
You are required to submit to the Office of Chief Counsel one
unredacted ``confidential version'' of the information for which you
are seeking confidential treatment. Pursuant to Sec. 512.6, the words
``ENTIRE PAGE CONFIDENTIAL BUSINESS INFORMATION'' or ``CONFIDENTIAL
BUSINESS INFORMATION CONTAINED WITHIN BRACKETS'' (as applicable) must
appear at the top of each page containing information claimed to be
confidential. In the latter
[[Page 104350]]
situation, where not all information on the page is claimed to be
confidential, identify each item of information for which
confidentiality is requested within brackets: ``[ ].''
You are also required to submit to the Office of Chief Counsel one
redacted ``public version'' of the information for which you are
seeking confidential treatment. Pursuant to Sec. 512.5(a)(2), the
redacted ``public version'' should include redactions of any
information for which you are seeking confidential treatment (i.e., the
only information that should be unredacted is information for which you
are not seeking confidential treatment).
NHTSA is currently treating electronic submission as an acceptable
method for submitting confidential business information to the agency
under part 512. Please do not send a hardcopy of a request for
confidential treatment to NHTSA's headquarters. The request should be
sent to Dan Rabinovitz in the Office of the Chief Counsel at
[email protected]. You may either submit your request via email
or request a secure file transfer link. If you are submitting the
request via email, please also email a courtesy copy of the request to
K. Helena Sung at [email protected].
List of Subjects
49 CFR Part 561
Imports, Incorporation by reference, Motor vehicles, Motor vehicle
safety.
49 CFR Part 571
Imports, Motor vehicles, Motor vehicle safety.
In consideration of the foregoing, NHTSA amends 49 CFR chapter V as
set forth below.
0
1. Add part 561 to read as follows:
PART 561--DOCUMENTATION FOR ELECTRIC-POWERED VEHICLES.
Sec.
561.1 Scope.
561.2 Purpose.
561.3 Application.
561.4 Matter incorporated by reference.
561.5 Definitions.
561.6 Rescue sheets and emergency response guides.
561.7 Documentation for low temperature operation safety.
561.8 Documentation of a visual warning for malfunction of vehicle
controls that manage REESS operation.
561.9 Documentation of an audio-visual warning for a thermal event
in the REESS.
561.10 Documentation for single cell thermal runaway and propagation
safety risk mitigation.
561.11 Record retention.
Authority: 49 U.S.C. 322, 30111, 30115, 30117, and 30166;
delegation of authority at 49 CFR 1.95.
Sec. 561.1 Scope.
This part specifies requirements for the submission of standardized
emergency response guides (ERGs) and rescue sheets for electric-powered
vehicles. It also specifies requirements for other documentation, to be
submitted to NHTSA upon request, addressing low temperature operation
safety, warning in the event of malfunction of vehicle controls
managing Rechargeable Electrical Energy Storage System (REESS)
operations, warning in the case of a thermal event in the REESS, and
safety risk mitigation for thermal runaway and propagation.
Sec. 561.2 Purpose.
The purpose of this part is to ensure emergency response
information is readily available for first and second responders
regarding the safe handling of electric-powered vehicles and to ensure
vehicle occupants are alerted to potentially hazardous conditions. The
other documentation requirements are to ensure vehicle manufacturers
identify and address safety risks associated with the electric
propulsion system in addition to the requirements of part 571 of this
chapter.
Sec. 561.3 Application.
This part applies to passenger cars, multipurpose passenger
vehicles, trucks, and buses that use electrical propulsion components
with working voltages greater than 60 volts direct current (VDC) or 30
volts alternating current (VAC), and whose speed attainable over a
distance of 1.6 km on a paved level surface is more than 40 km/h.
(a) Rescue sheets and emergency response guides requirements.
Vehicles manufactured on or after December 22, 2025, are subject to
Sec. 561.6.
(b) Documentation requirements. (1) Vehicles with a gross vehicle
weight rating of 4,536 kilograms (kg) or less manufactured on or after
September 1, 2027, are subject to Sec. Sec. 561.7 through 561.10.
(2) Vehicles with a gross vehicle weight rating over 4,536
kilograms (kg) manufactured on or after September 1, 2028, are subject
to Sec. Sec. 561.7 through 561.10.
(3) The requirements Sec. Sec. 561.7 through 561.10 do not apply
to small-volume manufacturers, final-stage manufacturers, and alterers
of vehicles with a gross vehicle weight rating under 4,536 kilograms
(kg) until one year after the date specified in paragraph (b)(1) of
this section.
(4) The requirements Sec. Sec. 561.7 through 561.10 do not apply
to small-volume manufacturers, final-stage manufacturers, and alterers
of vehicles with a gross vehicle weight rating over 4,536 kilograms
(kg) until one year after the date specified in paragraph (b)(2) of
this section.
Sec. 561.4 Matter incorporated by reference.
The material listed in this section is incorporated by reference
into this section with the approval of the Director of the Federal
Register in accordance with 5 U.S.C. 522(a) and 1 CFR part 51. All
approved incorporation by reference (IBR) material is available for
inspection at the National Highway Traffic Safety Administration
(NHTSA) or at the National Archives and Records Administration (NARA).
Contact NHTSA at: 1200 New Jersey Avenue SE, Washington, DC 20590;
(202) 366-2588; www.nhtsa.gov/about-nhtsa/electronic-reading-room. For
information on the availability of this material at NARA, visit
www.archives.gov/contact. The material may be obtained from the
following paragraphs of this section.
(a) International Organization for Standardization (ISO), 1, ch. de
la Voie-Creuse, CP 56, CH-1211 Geneva 20, Switzerland; phone: + 41 22
749 01 11; fax: + 41 22 733 34 30; website: www.iso.org.
(1) ISO 17840-1:2022(E), Road vehicles--Information for first and
second responders--Part 1: Rescue sheet for passenger cars and light
commercial vehicles, Second Edition, February 2022, into Sec. 561.6.
(2) ISO 17840-2:2019(E), Road vehicles--Information for first and
second responders--Part 2: Rescue sheet for buses, coaches and heavy
commercial vehicles, First edition, April 2019, into Sec. 561.6.
(3) ISO 17840-3:2019(E), Road vehicles--Information for first and
second responders--Part 3: Emergency response guide template, First
Edition, April 2019, into Sec. 561.6.
(b) [Reserved]
Sec. 561.5 Definitions.
(a) Statutory definitions. All terms defined in section 30102 of
the National Traffic and Motor Vehicle Safety Act (49 U.S.C. chapter
301, et seq.) are used in their statutory meaning.
(b) Motor vehicle safety standard definitions. All terms defined in
49 CFR part 571 are used as defined therein.
(c) Other definitions--
Emergency response guide means a document containing in-depth
vehicle-specific information related to fire,
[[Page 104351]]
submersion, leakage of fluids, towing, and storage of vehicles for
first and second responders.
First responder means a person with specialized training such as a
law enforcement officer, paramedic, emergency medical technician, and/
or firefighter.
Rescue sheet means an abbreviated version of an emergency response
guide that gives quick information about a vehicle's construction,
intended for use by first and second responders at the scene of a
crash.
Second responder means a worker who supports first responders by
cleaning up a site, towing vehicles, and/or supporting services after
an event requiring first responders.
Sec. 561.6 Rescue sheets and emergency response guides.
(a) Rescue sheets. Prior to first vehicle sale or lease, vehicle
manufacturers shall submit rescue sheets to NHTSA.
(1) For vehicles with a GVWR less than or equal to 4,536 kg to
which the requirement applies, submitted rescue sheets shall follow the
layout and format in ISO-17840-1:2022(E) (incorporated by reference;
see Sec. 561.4).
(2) For vehicles with a GVWR greater than 4,536 kg to which the
standard applies, the submitted rescue sheets shall follow the layout
and format in ISO-17840-2:2019(E) (incorporated by reference; see Sec.
561.4).
(3) The rescue sheets shall provide information for first
responders to extricate occupants.
(b) Emergency response guides (ERGs). Prior to first vehicle sale
or lease, vehicle manufacturers shall submit emergency response guides
to NHTSA in accordance with the template layout and format in ISO-
17840-3:2019(E) (incorporated by reference; see Sec. 561.4). vehicles
to which this requirement applies.
(1) The ERGs shall provide in-depth information linked and aligned
to the corresponding rescue sheet to support the quick and safe action
of first responders and second responders.
(2) The ERGs shall provide in-depth information related to electric
vehicle fire, submersion, leakage of fluids, towing, transportation,
and storage.
(3) The ERGs shall provide information to assist first responders
in extricating occupants.
Sec. 561.7 Documentation for low temperature operation safety.
At NHTSA's request, each manufacturer shall submit documentation
that includes the following:
(a) The make, model, model year, and production dates of the
vehicles to which the submitted documentation applies.
(b) The lower temperature boundary for safe REESS operation in all
vehicle operating modes.
(c) A description and explanation of charge and discharge rates at
the manufacturer specified lower temperature boundary for safe REESS
operation.
(d) A description of the method used to detect REESS temperature.
(e) A system diagram with key components and subsystems involved in
maintaining safe REESS charging and discharging operation for
temperatures at or below the manufacturer specified lower temperature
boundary for safe REESS operation.
(f) A description of how the vehicle controls, ancillary equipment,
and design features were validated and verified for maintaining safe
REESS operations at or below the manufacturer specified lower
temperature boundary for safe REESS operation.
(g) Overall evaluation: A description of the final manufacturer
review/audit process and results of any final review or audit
evaluating the technical content and the completeness and verity of
paragraphs (a) through (f) of this section.
Sec. 561.8 Documentation of a visual warning for malfunction of
vehicle controls that manage REESS operation.
At NHTSA's request, each manufacturer shall submit documentation
that includes the following:
(a) The make, model, model year, and production dates of the
vehicles to which the submitted documentation applies.
(b) A system diagram that identifies all the vehicle controls that
manage REESS operation. The diagram must identify what components are
used to generate a visual warning indicating malfunction of vehicle
controls to conduct one or more basic REESS operations.
(c) A written explanation describing the basic operation of the
vehicle controls that manage REESS operation. The explanation must
identify the components of the vehicle control system, provide
description of their functions and capability to manage the REESS, and
provide a logic diagram and description of conditions that would lead
to triggering the telltale activation.
(d) Validation results from tests to confirm the display of a
visual warning in the presence of a malfunction of the vehicle controls
which manage safe operation of the REESS.
(e) Overall evaluation: A description of the final manufacturer
review/audit process and results of the final review or audit which
evaluated the technical content and the completeness and verity of
paragraphs (a) through (d) of this section.
Sec. 561.9 Documentation of an audio-visual warning for a thermal
event in the REESS.
At NHTSA's request, each manufacturer shall submit documentation
that includes the following:
(a) The make, model, model year, and production dates of the
vehicles to which the submitted documentation applies.
(b) A system diagram of the thermal event warning system.
(c) A written explanation describing the basic operation of the
thermal event warning system. The explanation must identify the
components of the thermal event warning system, provide descriptions of
their functions and capability, and provide a logic diagram and
description of conditions that would lead to triggering the warning
activation.
(d) Validation results from tests to confirm the activation of an
audio-visual warning in the case of a thermal event in the REESS.
(e) Overall evaluation: A description of the final manufacturer
review/audit process and results of the final review or audit which
evaluated the technical content and the completeness and verity of
paragraphs (a) through (d) of this section.
Sec. 561.10 Documentation for single cell thermal runaway and
propagation safety risk mitigation.
The vehicle manufacturer shall make available to NHTSA, upon
request, documentation demonstrating how the vehicle and its REESS are
designed to mitigate the safety risks associated with thermal
propagation resulting from a single cell thermal runaway due to an
internal short within the cell. The documentation shall demonstrate
thermal propagation safety risk mitigation for the vehicle in external
charging mode, active driving possible mode, and parking mode. The
documentation shall include the following:
(a) Vehicle information. This part of the documentation shall
identify the make, model, model year, and production dates of the
vehicles to which the submitted documentation applies.
(b) Part I: System analysis. This part of the documentation shall
identify the conditions which could lead to single-cell thermal runaway
due to an internal short-circuit in different vehicle
[[Page 104352]]
operational modes and allocate applicable functional units, components,
and subsystems to each identified condition. This part shall include:
(1) A system diagram and a description of all relevant physical
systems and components of the REESS, including information about the
cell type and electrical configuration, cell chemistry, electrical
capacity, voltage, current limits during charging and discharging, and
thermal limits of the components that are critical for thermal
propagation safety.
(2) A system diagram, operational description of sensors,
components, functional units relevant to single-cell thermal runaway
due to internal short-circuit and thermal propagation, and the
interrelationship among the identified sensors, components, and
functional units;
(3) A description of conditions under which a single-cell thermal
runaway and propagation event due to an internal short-circuit could
occur;
(4) A description of how the identified conditions were allocated
to each identified component, functional unit, and subsystem;
(5) A description of the process used to review the identified
conditions and their allocation to the identified sensors, components,
and functional units, for completeness and validity; and
(6) A description of the warning or notification system before the
thermal runaway occurs, including a description of the detection
technology and mitigation strategies, if any.
(c) Part II: Safety risk assessment and mitigation process. This
part of the documentation shall identify thermal propagation safety
risk mitigation strategies for identified conditions leading to single
cell thermal runaway in Part I and include:
(1) A description of the safety risks and safety risk mitigation
strategies, and how these were identified, and
(2) A description of how each risk mitigation strategy manages,
mitigates, or prevents the identified safety risks.
(3) Safety risk mitigation strategies identified should include
those that mitigate the risk of single cell thermal runaway due to an
internal short and mitigate the occurrence of thermal propagation due
to single-cell thermal runaway resulting from an internal short-circuit
within the cell.
(d) Part III: Verification and validation of risk mitigation
strategies. This part of the documentation pertains to verification
that the manufacturer identified safety risks and considered safety
risk mitigation strategies and shall include:
(1) A description of how each risk mitigation strategy was verified
and validated for effectiveness,
(2) A description of the verification and validation results for
each risk mitigation strategy, and
(3) A description of and results from the vehicle level assessment.
(e) Part IV: Overall evaluation of risk mitigation. This part of
the documentation summarizes the vehicle design and manufacturing
strategies and their validation to mitigate the safety risks associated
with thermal propagation due to single cell thermal runaway resulting
from internal short within a cell. This part shall include a
description of the final manufacturer review/audit process and results
of the final review or audit evaluating the technical content and the
completeness and verity of paragraphs (a) through (d) of this section.
Sec. 561.11 Record retention.
Each applicable manufacturer shall maintain the information
specified in Sec. Sec. 561.7 through 561.10 for the documentation
requirements for a period of five years from the date of manufacture.
PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS
0
2. The authority citation for part 571 continues to read as follows:
Authority: 49 U.S.C. 322, 30111, 30115, 30117, and 30166;
delegation of authority at 49 CFR 1.95.
0
3. Section 571.305 is amended by revising the section heading and S3 to
read as follows:
Sec. 571.305 Standard No. 305; electric-powered vehicles:
electrolyte spillage and electrical shock protection; applicable unless
a vehicle is certified to Sec. 571.305a.
* * * * *
S3. Application. This standard applies to passenger cars, and to
multipurpose passenger vehicles, trucks, and buses with a gross vehicle
weight rating (GVWR) of 4,536 kilograms (kg) or less, that use
electrical propulsion components with working voltages greater than 60
volts direct current (VDC) or 30 volts alternating current (VAC), and
whose speed attainable over a distance of 1.6 km on a paved level
surface is more than 40 km/h, that are manufactured before September 1,
2027.
* * * * *
0
4. Section 571.305a is added to read as follows:
Sec. 571.305a Standard No. 305a; electric-powered vehicles: Electric
powertrain integrity; mandatory applicability begins on September 1,
2027.
S1. Scope. This standard specifies requirements for protection from
harmful electric shock, fire, explosion, and gas venting during normal
vehicle operation and during and after a crash.
S2. Purpose. The purpose of this standard is to reduce deaths and
injuries during normal vehicle operations and during and after a crash
that occur because of electrolyte leakage, intrusion of electric energy
storage/conversion devices into the occupant compartment, electric
shock, fire, explosion, and gas venting, including deaths and injuries
due to driver error.
S3. Application. (a) This standard applies to passenger cars,
multipurpose passenger vehicles, trucks, and buses that use electrical
propulsion components with working voltages greater than 60 volts
direct current (VDC) or 30 volts alternating current (VAC), and whose
speed attainable over a distance of 1.6 km on a paved level surface is
more than 40 km/h.
(b) Mandatory applicability begins September 1, 2027, for vehicles
with a gross vehicle weight rating of 4,536 kilograms (kg) or less and
September 1, 2028, for vehicles with a gross vehicle weight rating over
4,536 kg. Small-volume manufacturers, final-stage manufacturers, and
alterers are provided an additional year to comply with the
requirements beyond the dates identified in this paragraph (b).
S4. Definitions.
Active driving possible mode means the vehicle mode when
application of pressure to the accelerator pedal (or activation of an
equivalent control) or release of the brake system causes the electric
power train to move the vehicle.
Automatic disconnect means a device that when triggered,
conductively separates a high voltage source from the electric power
train or the rest of the electric power train.
Breakout harness means connector wires that are connected for
testing purposes to the REESS on the traction side of the automatic
disconnect.
Capacitor means a device used to store electrical energy,
consisting of one or more pairs of conductors separated by an
insulator: x-capacitors are connected between electrical mains or
neutral and y-capacitors are connected between a main to ground.
Charge connector is a conductive device that, by insertion into a
vehicle charge inlet, establishes an electrical connection of the
vehicle to an external electric power supply for the purpose of
transferring energy.
[[Page 104353]]
Chassis dynamometer means a mechanical device that uses one or more
fixed roller assemblies to simulate different road conditions within a
controlled environment and is used for a wide variety of vehicle
testing.
Connector means a device providing mechanical connection and
disconnection of high voltage electrical conductors to a suitable
mating component, including its housing.
n C Rate means the constant current of the REESS, which takes 1/n
hours to charge or discharge the REESS between 0 and 100 percent state
of charge.
Direct contact is the contact of any person or persons with high
voltage live parts.
Electric energy storage device means a high voltage source that
stores energy for vehicle propulsion. This includes, but is not limited
to, a high voltage battery or battery pack, rechargeable energy storage
device, and capacitor module.
Electric energy storage/conversion device means a high voltage
source that stores or converts energy for vehicle propulsion. This
includes, but is not limited to, a high voltage battery or battery
pack, fuel cell stack, rechargeable energy storage device, and
capacitor module.
Electric energy storage/conversion system means an assembly of
electrical components that stores or converts electrical energy for
vehicle propulsion. This includes, but is not limited to, high voltage
batteries or battery packs, fuel cell stacks, rechargeable energy
storage systems, capacitor modules, inverters, interconnects, and
venting systems.
Electric power train means an assembly of electrically connected
components which includes, but is not limited to, electric energy
storage/conversion systems and propulsion systems.
Electrical chassis means conductive parts of the vehicle whose
electrical potential is taken as reference and which are:
(1) Conductively linked together, and
(2) Not high voltage sources during normal vehicle operation.
Electrical isolation of a high voltage source in the vehicle means
the electrical resistance between the high voltage source and any of
the vehicle's electrical chassis divided by the working voltage of the
high voltage source.
Electrical protection barrier is the part providing protection
against direct contact with high voltage live parts from any direction
of access.
Electrolyte leakage means the escape of liquid electrolyte from the
REESS.
Exposed conductive part is a conductive part that can be touched
under the provisions of the IPXXB protection degree and that is not
normally energized, but that can become electrically energized under
isolation fault conditions. This includes parts under a cover if the
cover can be removed without using tools.
External charging mode means the vehicle mode when the REESS is
charging with external electric power supply connected through the
charge connector to the vehicle charge inlet.
External electric power supply is a power supply external to the
vehicle that provides electric power to charge the electric energy
storage device in the vehicle through the charge connector.
Fuel cell system is a system containing the fuel cell stack(s), air
processing system, fuel flow control system, exhaust system, thermal
management system, and water management system.
High voltage live part means a live part of a high voltage source.
High voltage source means any electric component which is contained
in the electric power train or conductively connected to the electric
power train and has a working voltage greater than 30 VAC or 60 VDC.
Indirect contact is the contact of any person or persons with
exposed conductive parts.
Live part is a conductive part of the vehicle that is electrically
energized under normal vehicle operation.
Luggage compartment is the space in the vehicle for luggage
accommodation, separated from the passenger compartment by the front or
rear bulkhead and bounded by a roof, hood or trunk lid, floor, and side
walls, as well as by electrical protection barriers provided for
protecting the occupants from direct contact with high voltage live
parts.
Normal vehicle operation includes operating modes and conditions
that can reasonably be encountered during typical operation of the
vehicle, such as driving, parking, and standing in traffic, as well as
charging using chargers that are compatible with the specific charging
ports installed on the vehicle. It does not include conditions where
the vehicle is damaged, either by a crash or road debris, subjected to
fire or water submersion, or in a state where service and/or
maintenance is needed or being performed.
Parking mode is the vehicle mode in which the vehicle power is
turned off, the vehicle propulsion system and ancillary equipment such
as the radio are not operational, and the vehicle is stationary.
Passenger compartment is the space for occupant accommodation that
is bounded by the roof, floor, side walls, doors, outside glazing,
front bulkhead and rear bulkhead or rear gate, as well as electrical
protection barriers provided for protecting the occupants from direct
contact with high voltage live parts.
Propulsion system means an assembly of electric or electro-
mechanical components or circuits that propel the vehicle using the
energy that is supplied by a high voltage source. This includes, but is
not limited to, electric motors, inverters/converters, and electronic
controllers.
Protection degree IPXXB is protection from contact with high
voltage live parts. It is tested by probing electrical protection
barriers with the jointed test finger probe, IPXXB, in figure 7b to
this standard.
Protection degree IPXXD is protection from contact with high
voltage live parts. It is tested by probing electrical protection
barriers with the test wire probe, IPXXD, in figure 7a to this
standard.
Rechargeable Electrical Energy Storage System (REESS) means the
rechargeable electric energy storage system that provides electric
energy for electrical propulsion.
Rupture means an opening through the casing of the REESS that would
permit the IPXXB test probe to penetrate and contact live parts.
Service disconnect is the device for deactivation of an electrical
circuit when conducting checks and services of the vehicle electrical
propulsion system.
State of charge (SOC) means the available electrical charge in a
REESS expressed as a percentage of the normal operating capacity
specified by the vehicle manufacturer.
Thermal event means the condition when the temperature within the
REESS is significantly higher than the maximum operating temperature.
Thermal runaway means an uncontrolled increase of cell temperature
caused by exothermic reactions inside the cell.
Thermal propagation means the sequential occurrence of thermal
runaway within a REESS triggered by thermal runaway of a cell in the
REESS.
VAC means volts of alternating current (AC) expressed using the
root mean square value.
VDC means volts of direct current (DC).
Vehicle charge inlet is the device on the electric vehicle into
which the charge connector is inserted for the purpose of transferring
energy and exchanging information from an external electric power
supply.
[[Page 104354]]
Venting means the release of excessive internal pressure from cell
or battery in a manner intended by design to preclude rupture or
explosion.
Working voltage means the highest root mean square voltage of the
voltage source, which may occur across its terminals or between its
terminals and any conductive parts in open circuit conditions or under
normal operating conditions.
S5. General requirements.
S5.1 Vehicles of GVWR of 4,536 kilograms (kg) or less (light
vehicles). Each vehicle with a GVWR of 4,536 kg or less shall meet the
requirements set forth in S6 (normal vehicle operation safety), S8
(post-crash safety), S11 (vehicle controls managing REESS safe
operations), S13 (warning in the case of thermal event in REESS), and
S14 (water exposure safety) of this standard.
S5.2 Vehicles with a GVWR greater than 4,536 kg other than school
buses (heavy vehicles other than school buses). Each heavy vehicle with
a GVWR greater than 4,536 kg, other than school buses, shall meet the
requirements set forth in S6 (normal vehicle operation safety), S11
(vehicle controls managing REESS safe operations), S13 (warning in the
case of thermal event in REESS), and S14 (water exposure safety) of
this standard.
S5.3 School buses with a GVWR greater than 4,536 kg. Each school
bus with a GVWR greater than 4,536 kg shall meet the requirements set
forth in S6 (normal vehicle operation safety), S8 (post-crash safety),
S11 (vehicle controls managing REESS safe operations), S13 (warning in
the case of thermal event in REESS), and S14 (water exposure safety) of
this standard.
S6. Normal vehicle operation safety. Each vehicle to which this
standard applies must meet the requirements in S6.1 to S6.6 of this
standard, when tested according to the relevant provisions in S7 of
this standard.
S6.1 Protection against direct contact.
S6.1.1 Marking. The symbol shown in figure 6 to this standard shall
be present on or near electric energy storage devices. The symbol in
figure 6 shall also be visible on electrical protection barriers which,
when removed, expose live parts of high voltage sources. The symbol
shall be yellow and the bordering and the arrow shall be black.
S6.1.1.1 The marking is not required for electrical protection
barriers that cannot be physically accessed, opened, or removed without
the use of tools. Markings are not required for electrical connectors
or the vehicle charge inlet.
S6.1.2 High voltage cables. Cables for high voltage sources which
are not located within electrical protection barriers shall be
identified by having an outer covering with the color orange.
S6.1.3 Service disconnect. For a service disconnect which can be
opened, disassembled, or removed without tools, protection degree IPXXB
shall be provided when tested under procedures specified in S7.3.1 of
this standard using the IPXXB test probe shown in figures 7a and 7b to
this standard.
S6.1.4 Protection degree of high voltage live parts. (a) Protection
degree IPXXD shall be provided for high voltage live parts inside the
passenger or luggage compartment when tested according to the
procedures specified in S7.3.1 of this standard using the IPXXD test
probe shown in figure 7a to this standard.
(b) Protection degree IPXXB shall be provided for high voltage live
parts in areas other than the passenger or luggage compartment when
tested according to the procedures specified in S7.3.1 of this standard
using the IPXXB test probe shown in figures 7a and 7b to this standard.
High voltage live parts that are not energized except during charging
of the REESS are excluded from protection degree IPXXB if they are
located on the vehicle roof such that the wrap around distance from the
instep of the vehicle, or the lowest step (if multiple steps are
present) of the vehicle, to the high voltage source is at least 3
meters.
S6.1.5 Connectors. All connectors shall provide direct contact
protection by:
(a) Meeting the requirements specified in S6.1.4 when the connector
is connected to its corresponding mating component; and,
(b) If a connector can be separated from its mating component
without the use of a tool, meeting at least one of the following
conditions from S6.1.5(b)(1), (2), or (3):
(1) The connector meets the requirements of S6.1.4 when separated
from its mating component;
(2) The voltage of the live parts becomes less than or equal to 60
VDC or 30 VAC within one second after the connector is separated from
its mating component; or
(3) The connector requires at least two distinct actions to
separate from its mating component and there are other components that
must be removed in order to separate the connector from its mating
component and these other components cannot be removed without the use
of tools.
S6.1.6 Vehicle charge inlet. Direct contact protection for a
vehicle charge inlet shall be provided by meeting the requirements
specified in S6.1.4 when the charge connector is connected to the
vehicle inlet and by meeting at least one of the requirements of
S6.1.6(a) or (b).
(a) The vehicle charge inlet meets the requirements of S6.1.4 when
the charge connector is not connected to it; or
(b) The voltage of the high voltage live parts becomes equal to or
less than 60 VDC or equal to or less than 30 VAC within 1 second after
the charge connector is separated from the vehicle charge inlet.
S6.2 Protection against indirect contact.
S6.2.1 The resistance between all exposed conductive parts of
electrical protection barriers and the electrical chassis shall be less
than 0.1 ohms when tested according to the procedures specified in
S7.3.2 of this standard.
S6.2.2 The resistance between any two simultaneously reachable
exposed conductive parts of the electrical protection barriers that are
less than 2.5 meters from each other shall be less than 0.2 ohms when
tested according to the procedures specified in S7.3.2 of this
standard.
S6.3 Electrical isolation.
S6.3.1 Electrical isolation of AC and DC high voltage sources. The
electrical isolation of a high voltage source, determined in accordance
with the procedure specified in S7.2 of this standard, must be greater
than or equal to one of the following:
(a) 500 ohms/volt for an AC high voltage source;
(b) 100 ohms/volt for an AC high voltage source if it is
conductively connected to a DC high voltage source, but only if the AC
high voltage source meets the requirements for protection against
direct contact in S6.1.4 and the protection from indirect contact in
S6.2; or
(c) 100 ohms/volt for a DC high voltage source.
S6.3.2 Exclusion of high voltage sources from electrical isolation
requirements. A high voltage source that is conductively connected to
an electric component which is conductively connected to the electrical
chassis and has a working voltage less than or equal to 60 VDC,
including a pulsating DC voltage source without a change in polarity,
is not required to meet the electrical isolation requirements in S6.3.1
if the voltage between the high voltage source and the electrical
chassis is less than or equal to 30 VAC or 60 VDC.
S6.3.3 Electrical isolation of high voltage sources for charging
the electric
[[Page 104355]]
energy storage device. For the vehicle charge inlet intended to be
conductively connected to the AC external electric power supply, the
electric isolation between the electrical chassis and the high voltage
sources that are conductively connected to the vehicle charge inlet
during charging of the electric energy storage device shall be greater
than or equal to 500 ohms/volt when the charge connector is
disconnected. The electrical isolation is measured at the high voltage
live parts of the vehicle charge inlet and determined in accordance
with the procedure specified in S7.2 of this standard. During the
measurement, the electric energy storage device may be disconnected.
S6.4 Electrical isolation monitoring. DC high voltage sources of
vehicles with a fuel cell system shall be monitored by an electrical
isolation monitoring system that displays a warning for loss of
isolation when tested according to S7.4 of this standard. The system
must monitor its own readiness and the visual warning display must be
provided to the driver. For a vehicle with automated driving systems
and without manually operated driving controls, the visual warning must
be provided to all the front row occupants.
S6.5 Electric shock protection during charging. For motor vehicles
with an electric energy storage device that can be charged through a
conductive connection with a grounded external electric power supply, a
device to enable conductive connection of the electrical chassis to the
earth ground shall be provided. This device shall enable connection to
the earth ground before exterior voltage is applied to the vehicle and
retain the connection until after the exterior voltage is removed from
the vehicle.
S6.6 Mitigating driver error.
S6.6.1 Indicator of active driving possible mode. At least a
momentary indication shall be given to the driver each time the vehicle
is first placed in active driving possible mode after manual activation
of the propulsion system. This requirement does not apply under
conditions where an internal combustion engine directly or indirectly
provides the vehicle's propulsion power when the vehicle is first
placed in the active driving possible mode after manual activation of
the propulsion system.
S6.6.2 Indicator of active driving possible mode when leaving the
vehicle. When leaving the vehicle, the driver shall be informed by an
auditory or visual signal if the vehicle is still in the active driving
possible mode.
S6.6.3 Prevent drive-away. If the on-board electric energy storage
device can be externally charged, vehicle movement of more than 150 mm
by its own propulsion system shall not be possible as long as the
charge connector of the external electric power supply is physically
connected to the vehicle charge inlet in a manner that would permit
charging of the electric energy storage device.
S7. Electrical safety test procedures for normal vehicle operation
safety. The following provisions specify the test procedures associated
with the requirements of S6 of this standard.
S7.1 Voltage measurements. For the purpose of determining the
voltage level of the high voltage source, voltage is measured as shown
in figure 1 to this standard using a voltmeter that has an internal
resistance of at least 10 M[Omega]. All post-crash voltage measurements
for determining electrical isolation of high voltage sources specified
in S8.2(a) of this standard are made at least 10 seconds after impact.
All post-crash voltage measurements for determining the voltage levels
specified in S8.2(b) of this standard and the energy in capacitors
specified in S8.2(d) of this standard are made between 10 to 60 seconds
after impact.
S7.1.1 For a high voltage source that has an automatic disconnect
that is physically contained within itself, the voltage measurement
after the test is made from the side of the automatic disconnect
connected to the electric power train or to the rest of the electric
power train if the high voltage source is a component contained in the
power train. For a high voltage source that has an automatic disconnect
that is not physically contained within itself, the voltage measurement
after the test is made from both the high voltage source side of the
automatic disconnect and from the side of the automatic disconnect
connected to the electric power train or to the rest of the electric
power train if the high voltage source is a component contained in the
power train.
S7.1.2 Voltage Vb is measured across the two terminals of the
voltage source. Before a vehicle crash test, Vb is equal to or greater
than the working voltage as specified by the vehicle manufacturer.
S7.1.3 Voltage V1 is measured between the negative side of the high
voltage source and the electrical chassis as shown in figure 2 to this
standard. Voltage V2 is measured between the positive side of the high
voltage source and the electrical chassis as shown in figure 3 to this
standard.
S7.2 Test method for determining electrical isolation. Measure the
voltages V1, V2, and Vb as shown in figure 1 to this standard in
accordance with S7.1.
S7.2.1 If V1 is greater than or equal to V2, insert a known
resistance (Ro) between the negative side of the high voltage source
and the electrical chassis. With the Ro installed, measure the voltage
(V1') as shown in figure 4 to this standard between the negative side
of the high voltage source and the electrical chassis. Calculate the
electrical isolation resistance (Ri) according to the formula shown.
Divide Ri (in ohms) by the working voltage of the high voltage source
(in volts) to obtain the electrical isolation (in ohms/volt).
S7.2.2 If V2 is greater than V1, insert a known resistance (Ro)
between the positive side of the high voltage source and the electrical
chassis. With the Ro installed, measure the voltage (V2') as shown in
figure 5 to this standard between the positive side of the high voltage
source and the electrical chassis. Calculate the electrical isolation
resistance (Ri) according to the formula shown. Divide Ri (in ohms) by
the working voltage of the high voltage source (in volts) to obtain the
electrical isolation (in ohms/volt).
S7.3 Test methods for evaluating physical barrier protection.
S7.3.1 Test method to evaluate protection from direct contact with
high voltage sources. (a) Any parts surrounding the high voltage
components are opened, disassembled, or removed without the use of
tools.
(b) The selected access probe is inserted into any gaps or openings
of the electrical protection barrier with a test force between 9 Newton
to 11 Newton with the IPXXB probe or 1 Newton to 2 Newton with the
IPXXD probe. If the probe partly or fully penetrates into the
electrical protection barrier, it is placed in every possible position
to evaluate contact with high voltage live parts. If partial or full
penetration into the electrical protection barrier occurs with the
IPXXB probe, the IPXXB probe shall be placed as follows: starting from
the straight position, both joints of the test finger are rotated
progressively through an angle of up to 90 degrees with respect to the
axis of the adjoining section of the test finger and are placed in
every possible position.
(c) A low voltage supply (of not less than 40 V and not more than
50 V) in series with a suitable lamp may be connected between the
access probe and any high voltage live parts inside the electrical
protection barrier to indicate whether high voltage live parts were
contacted.
[[Page 104356]]
(d) A mirror or fiberscope may be used to inspect whether the
access probe touches high voltage live parts inside the electrical
protection barrier.
(e) Protection degree IPXXD or IPXXB is verified when the following
conditions are met:
(1) The access probe does not touch high voltage live parts. The
IPXXB access probe may be manipulated as specified in S7.3.1(b) for
evaluating contact with high voltage live parts. The methods specified
in S7.3.1(c) or S7.3.1(d) may be used to aid the evaluation. If method
S7.3.1(c) is used for verifying protection degree IPXXB or IPXXD, the
lamp shall not light up.
(2) The stop face of the access probe does not fully penetrate into
the electrical protection barrier.
S7.3.2 Test method to evaluate protection against indirect contact
with high voltage sources. Any parts surrounding the high voltage
components are opened, disassembled, or removed without the use of
tools. At the option of the manufacturer, protection against indirect
contact with high voltage sources shall be determined using the test
method in S7.3.2(a) or (b).
(a) Test method using a resistance tester. The resistance tester is
connected to the measuring points (the electrical chassis and any
exposed conductive part of electrical protection barriers or any two
simultaneously reachable exposed conductive parts of electrical
protection barriers that are less than 2.5 meters from each other), and
the resistance is measured using a resistance tester that can supply
current levels of at least 0.2 Amperes with a resolution of 0.01 ohms
or less. The resistance between two exposed conductive parts of
electrical protection barriers that are less than 2.5 meters from each
other may be calculated using the separately measured resistances of
the relevant parts of the electric path.
(b) Test method using a DC power supply, voltmeter, and ammeter.
(1) Connect the DC power supply, voltmeter, and ammeter to the
measuring points (the electrical chassis and any exposed conductive
part or any two simultaneously reachable exposed conductive parts that
are less than 2.5 meters from each other) as shown in figure 8 to this
standard.
(2) Adjust the voltage of the DC power supply so that the current
flow becomes more than 0.2 Amperes.
(3) Measure the current I and the voltage V shown in figure 8 to
this standard.
(4) Calculate the resistance R according to the formula, R = V/I.
(5) The resistance between two simultaneously reachable exposed
conductive parts of electrical protection barriers that are less than
2.5 meters from each other may be calculated using the separately
measured resistances of the relevant parts of the electric path.
S7.3.3 Test method to determine voltage between exposed conductive
parts of electrical protection barriers and the electrical chassis and
between exposed conductive parts of electrical protection barriers. (a)
Any parts surrounding the high voltage components are opened,
disassembled, or removed without the use of tools.
(b) Connect the voltmeter to the measuring points (exposed
conductive part of an electrical protection barrier and the electrical
chassis or any two simultaneously reachable exposed conductive parts of
electrical protection barriers that are less than 2.5 meters from each
other).
(c) Measure the voltage.
(d) The voltage between two simultaneously reachable exposed
conductive parts of electrical protection barriers that are less than
2.5 meters from each other may be calculated using the separately
measured voltages between the relevant electrical protection barriers
and the electrical chassis.
S7.4 Test method for evaluating on-board electrical isolation
monitoring system. Prior to any impact test, the requirements of S6.4
of this standard for the on-board electrical isolation monitoring
system shall be tested using the following procedure.
(a) The electric energy storage device is at the state of charge
specified in S7.1.
(b) The switch or device that provides power from the electric
energy storage/conversion system to the propulsion system is in the
activated position or the ready-to-drive position.
(c) Determine the isolation resistance, Ri, of the high voltage
source with the electrical isolation monitoring system using the
procedure outlined in S7.2.
(d) Insert a resistor with resistance Ro equal to or greater than
1/(1/(95 times the working voltage of the high voltage source)-1/Ri)
and less than 1/(1/(100 times the working voltage of the high voltage
source)-1/Ri) between the positive terminal of the high voltage source
and the electrical chassis.
(e) The electrical isolation monitoring system indicator shall
provide a visual warning to the driver. For a vehicle with automated
driving systems and without manually operated driving controls, the
visual warning must be provided to all the front row occupants.
S7.5 Test method for determining post-crash energy in capacitors.
(a) Prior to the crash tests, the vehicle manufacturer must identify
the capacitors, type of capacitors (x-capacitors and y-capacitors) and
their respective capacitance (Cx and Cy1 and Cy2)
in the electric power train for which the low energy compliance option
for post-crash electrical safety in S8.2(d) of this standard is
applied.
(b) Voltages Vb, V1, and V2 are measured across the capacitors in
accordance with S7.1.
(c) The total energy in a x-capacitor is equal to 0.5 x Cx x Vb\2\.
(d) The total energy in the y-capacitor Cy1 is equal to
0.5 x Cy1 x V1\2\ and the total energy in the y-capacitor
Cy2 is equal to 0.5 x Cy2 x V2\2\.
S8. Post-crash safety. Each vehicle with a GVWR of 4,536 kg or less
to which this standard applies must meet the requirements in S8.1,
S8.2, S8.3, and S8.4 when tested according to S9 of this standard under
the conditions of S10 of this standard. Each school bus with a GVWR
greater than 4,536 kg to which this standard applies must meet the
requirements in S8.1, S8.2, S8.3, and S8.4 when tested according to
S9.5 of this standard under the conditions of S10.
S8.1 Fire safety. Starting from the time of impact and continuing
until one hour after the completion of the sequence of tests specified
in S9 of this standard, there shall be no evidence of fire or explosion
in any part of the vehicle. The assessment of fire or explosion is
verified by visual inspection without disassembly of the REESS or
vehicle.
S8.2 Electrical safety. After each test specified in S9 of this
standard, each high voltage source in a vehicle must meet one of the
following electrical safety requirements: electrical isolation
requirements of S8.2(a), the voltage level requirements of S8.2 (b), or
the physical barrier protection requirements of S8.2(c); or the high
voltage capacitors in the electric power train must meet the low-energy
requirements of S8.2(d).
(a) The electrical isolation of the high voltage source, determined
in accordance with the procedure specified in S7.2 of this standard,
must be greater than or equal to one of the following:
(1) 500 ohms/volt for an AC high voltage source;
(2) 100 ohms/volt for an AC high voltage source if it is
conductively connected to a DC high voltage source, but only if the AC
high voltage source meets the physical barrier protection requirements
specified in S8.2(c)(1) and (2); or
(3) 100 ohms/volt for a DC high voltage source.
[[Page 104357]]
(b) The voltages V1, V2, and Vb of the high voltage source,
measured according to the procedure specified in S7.1 of this standard,
must be less than or equal to 30 VAC for AC components or 60 VDC for DC
components.
(c) Protection against electric shock by direct and indirect
contact (physical barrier protection) shall be demonstrated by meeting
the following three conditions:
(1) The high voltage source (AC or DC) meets the protection degree
IPXXB when tested according to the procedure specified in S7.3.1 of
this standard using the IPXXB test probe shown in figures 7a and 7b to
this standard;
(2) The resistance between exposed conductive parts of the
electrical protection barrier of the high voltage source and the
electrical chassis is less than 0.1 ohms when tested according to the
procedures specified in S7.3.2 of this standard. In addition, the
resistance between an exposed conductive part of the electrical
protection barrier of the high voltage source and any other
simultaneously reachable exposed conductive parts of electrical
protection barriers within 2.5 meters of it must be less than 0.2 ohms
when tested using the test procedures specified in S7.3.2 of this
standard; and
(3) The voltage between exposed conductive parts of the electrical
protection barrier of the high voltage source and the electrical
chassis is less than or equal to 30 VAC or 60 VDC as measured in
accordance with S7.3.3 of this standard. In addition, the voltage
between an exposed conductive part of the electrical protection barrier
of the high voltage source and any other simultaneously reachable
exposed conductive parts of electrical protection barriers within 2.5
meters of it must be less than or equal to 30 VAC or 60 VDC as measured
in accordance with S7.3.3 of this standard.
(d) The total energy of unidirectional single impulse currents from
capacitors shall be less than 0.2 Joules when determined in accordance
with the procedure specified in S7.5 of this standard.
S8.3 Electric energy storage/conversion device retention. During
and after each test specified in S9 of this standard:
(a) Electric energy storage/conversion devices shall remain
attached to the vehicle by at least one component anchorage, bracket,
or any structure that transfers loads from the device to the vehicle
structure, and
(b) Electric energy storage/conversion devices located outside the
occupant compartment shall not enter the occupant compartment.
S8.4 Electrolyte leakage from electric energy storage devices. Not
more than 5.0 liters of electrolyte shall leak from electric energy
storage devices, and no visible trace of electrolyte shall leak into
the passenger compartment. Leakage is measured from the time of the
impact until 30 minutes thereafter, and throughout any static rollover
after a barrier impact test, specified in S9 of this standard.
S9. Crash test specifications. A test vehicle with a GVWR less than
or equal to 4,536 kg, under the conditions of S10 of this standard, is
subject to any one single barrier crash test of S9.1, S9.2, or S9.3,
followed by the static rollover test of S9.4. A school bus with a GVWR
greater than 4,536 kg, under the conditions of S10, is subject to the
contoured barrier crash test of S9.5. A particular vehicle need not
meet further test requirements after having been subjected to a single
barrier crash/static rollover test sequence.
S9.1 Frontal barrier crash. The test vehicle, with test dummies in
accordance with S6.1 of Sec. 571.301, traveling longitudinally forward
at any speed up to and including 48 km/h, impacts a fixed collision
barrier that is perpendicular to the line of travel of the vehicle, or
at an angle up to 30 degrees in either direction from the perpendicular
to the line of travel of the vehicle.
S9.2 Rear moving barrier impact. The test vehicle, with test
dummies in accordance with S6.1 of Sec. 571.301, is impacted from the
rear by a barrier that conforms to S7.3(b) of Sec. 571.301 and that is
moving at any speed between 79 and 81 km/h.
S9.3 Side moving deformable barrier impact. The test vehicle, with
the appropriate 49 CFR part 572 test dummies specified in Sec. 571.214
at positions required for testing by S7.1.1, S7.2.1, or S7.2.2 of
Standard 214 (Sec. 571.214), is impacted laterally on either side by a
moving deformable barrier moving at any speed between 52.0 km/h and
54.0 km/h.
S9.4 Post-impact test static rollover. After each crash test
specified in S9.1, S9.2, and S9.3, without any alteration of the
vehicle, the vehicle is rotated on its longitudinal axis to each
successive increment of 90 degrees under the test conditions of S10.3
of this standard.
S9.5 Moving contoured barrier crash. The test vehicle, under the
conditions of S10.1 and S10.2 of this standard, is impacted at any
point and at any angle by the moving contoured barrier assembly,
specified in S7.5 and S7.6 in Sec. 571.301, traveling longitudinally
forward at any speed up to and including 48 km/h.
S10. Crash test conditions.
S10.1 State of charge. The electric energy storage device(s) shall
be at the state of charge specified in either S10.1(a), (b), or (c):
(a) At the maximum state of charge in accordance with the vehicle
manufacturer's recommended charging procedures, as stated in the
vehicle owner's manual or on a label that is permanently affixed to the
vehicle; or
(b) If the manufacturer has made no recommendation for charging
procedures in the owner's manual or on a label permanently affixed to
the vehicle, at a state of charge of not less than 95 percent of the
maximum capacity of the electric energy storage device(s); or
(c) If the electric energy storage device(s) is/are rechargeable
only by an energy source on the vehicle, at any state of charge within
the normal operating voltage defined by the vehicle manufacturer.
S10.2 Vehicle conditions. The switch or device that provides power
from the electric energy storage/conversion system to the propulsion
system is in the activated position or the ready-to-drive position.
Bypass any devices or systems that do not allow the propulsion system
to be energized at the time of impact when the vehicle ignition is on
and the vehicle is in neutral.
S10.2.1 The parking brake is disengaged and the vehicle drive
system is in the neutral position. In a test conducted under S9.3 of
this standard, the parking brake is set.
S10.2.2 Tires are inflated to the manufacturer's specifications.
S10.2.3 The vehicle, including test devices and instrumentation, is
loaded as follows:
(a) A passenger car is loaded to its unloaded vehicle weight plus
its rated cargo and luggage capacity weight, secured in the luggage
compartment, plus the necessary test dummies as specified in S9 of this
standard, restrained only by means that are installed in the vehicle
for protection at its seating position.
(b) A multipurpose passenger vehicle, truck, or bus, with a GVWR of
4,536 kg (10,000 lb) or less, is loaded to its unloaded vehicle weight
plus the necessary dummies, as specified in S9 of this standard, plus
136 kg or its rated GVWR, whichever is less, secured in the load
carrying area and distributed as nearly as possible in proportion to
its GVWR. For the purpose of this standard, unloaded vehicle weight
does not include the weight of work-performing accessories. Each dummy
is restrained only by means that are installed in the
[[Page 104358]]
vehicle for protection at its seating position.
(c) A school bus with a GVWR greater than 4,536 kg is loaded to its
unloaded vehicle weight, plus 54 kg of unsecured mass at each
designated seating position.
S10.3 Static rollover test conditions. The vehicle is rotated about
its longitudinal axis, with the axis kept horizontal, to each
successive increment of 90[deg], 180[deg], and 270[deg] at a uniform
rate, with 90[deg] of rotation taking place in any time interval from 1
to 3 minutes. After reaching each 90[deg] increment the vehicle is held
in that position for 5 minutes.
S10.4 Rear moving barrier impact test conditions. The conditions of
S7.3(b) and S7.6 of Sec. 571.301 apply to the conducting of the rear
moving deformable barrier impact test specified in S9.2 of this
standard.
S10.5 Side moving deformable barrier impact test conditions. The
conditions of S8.9, S8.10, and S8.11 of Sec. 571.214 apply to the
conduct of the side moving deformable barrier impact test specified in
S9.3 of this standard.
S11. Vehicle controls managing REESS safe operations. Each vehicle
to which the standard applies shall meet the requirements in S11.1,
when tested according to S12 of this standard and the requirements in
S11.2.
S11.1 When tested in accordance with the overcharge test in S12.1,
the over-discharge test in S12.2, the overcurrent test in S12.3, the
high-temperature test in S12.4, and the short circuit test in
accordance with S12.5 of this standard, each vehicle shall meet the
following:
(a) During the test, there shall be no evidence of electrolyte
leakage, rupture, venting, fire, or explosion of the REESS as verified
by visual inspection without disassembly of the vehicle.
(b) The isolation resistance of the high voltage sources measured
after the test shall not be less than 100 ohms/volt when determined in
accordance with S7.2 of this standard.
S11.2 In the event of operational failure of the vehicle controls
that manage safe operation of the REESS, the vehicle must provide a
visual warning while in active driving possible mode. The warning
system shall monitor its own readiness and the visual warning must be
provided to the driver. For a vehicle with automated driving systems
and without manually operated driving controls, the visual warning must
be provided to all the front row occupants.
S12. Test methods for evaluating vehicle controls managing REESS
safe operations.
S12.1 Overcharge test. The overcharge test is conducted at ambient
temperatures between 10 [deg]C and 30 [deg]C, with the vehicle REESS
initially set between 90 to 95 percent SOC. The following steps are
conducted to evaluate the vehicle's overcharge protection controls:
(a) A breakout harness is connected to the traction side of the
REESS. The manufacturer must specify an appropriate location(s) and
attachment point(s) to connect the breakout harness.
(b) Temperature probes are connected to the REESS outer casing to
monitor changes in REESS temperature. Temperature measurements may also
be obtained through communication with the REESS control module.
(c) The external charge/discharge equipment, with maximum voltage
and current set at least 10 percent higher than the REESS voltage and
current limits, is connected to the breakout harness.
(d) The vehicle switch or device that provides power to the vehicle
controls that manage REESS operations is set to the activated position.
(e) The REESS is charged with the external charge/discharge
equipment with the maximum charge current specified by the
manufacturer. If the manufacturer does not specify an appropriate
charge current, then a charge rate of \1/3\C is used.
(f) Charging is continued until one of the following occurs:
(1) The overcharge protection control terminates the charge
current;
(2) The REESS temperature is 10 [deg]C above the manufacturer-
specified maximum operating temperature of the REESS; or
(3) 12 hours have passed since the start of charging the vehicle.
(g) After the charge current is terminated, if charge and discharge
are permitted by the vehicle controls, a standard cycle is performed in
accordance with S12.6.
(h) After the completion of the standard cycle, or if the standard
cycle was not performed, after charging is terminated, the vehicle is
observed for 1 hour for evidence of electrolyte leakage, rupture,
venting, fire, or explosion of the REESS.
(i) At the conclusion of the test, electrical isolation of the
REESS is determined in accordance with S7.2 of this standard.
S12.2 Over-discharge test. The over-discharge test is conducted at
ambient temperatures between 10 [deg]C and 30 [deg]C, with the vehicle
REESS initially set between 10 and 15 percent SOC. For a vehicle with
on-board energy conversion systems such as an internal combustion
engine or a fuel cell, the fuel supply is set to the minimum level
where active driving possible mode is permitted. The following steps
are conducted to evaluate the vehicle's over-discharge protection
controls:
(a) A breakout harness is connected to the traction side of the
REESS. The manufacturer must specify an appropriate location(s) and
attachment point(s) to connect the breakout harness.
(b) Temperature probes are connected to the REESS outer casing to
monitor changes in REESS temperature. Temperature measurements may also
be obtained through communication with the REESS control module.
(c) The external charge/discharge equipment, with maximum voltage
and current set at least 10 percent higher than the REESS voltage and
current limits, is connected to the breakout harness.
(d) The vehicle switch or device that provides power from the REESS
to the electric power train is set to the activated position or the
active driving possible mode.
(e) The REESS is discharged with the external charge/discharge
equipment with the maximum discharge rate under normal operating
conditions specified by the manufacturer. If the manufacturer does not
specify an appropriate discharge rate, a power load of 1kW is used.
(f) Discharging is continued until one of the following occurs:
(1) The over-discharge protection control terminates the discharge
current;
(2) The temperature gradient of the REESS is less than 4[deg]C
through 2 hours from the start of discharge; or
(3) The vehicle is discharged to 25 percent of its working voltage
level.
(g) After the discharge current is terminated, a standard cycle is
performed in accordance with S12.6, if charge and discharge are
permitted by the vehicle controls.
(h) After the completion of the standard cycle, or if the standard
cycle was not performed, after discharging is terminated, the vehicle
is observed for 1 hour for evidence of electrolyte leakage, rupture,
venting, fire, or explosion of the REESS.
(i) At the conclusion of the test, electrical isolation of the
REESS is determined in accordance with S7.2 of this standard.
S12.3 Overcurrent test. The overcurrent test is only conducted on
vehicles that have the capability of charging by DC external
electricity supply. The test is conducted at ambient temperatures
between 10 [deg]C and 30 [deg]C, with the vehicle REESS initially set
between 40 to 50 percent SOC. The following steps are conducted to
[[Page 104359]]
evaluate the vehicle's over-current protection controls:
(a) A breakout harness is connected to the traction side of the
REESS. The manufacturer must specify an appropriate location(s) and
attachment point(s) to connect the breakout harness.
(b) Temperature probes are connected to the REESS outer casing to
monitor changes in REESS temperature. Temperature measurements may also
be obtained through communication with the REESS control module.
(c) The external charge/discharge equipment, with maximum voltage
and current set at least 10 percent higher than the REESS voltage and
current limits, is connected to the breakout harness.
(d) The vehicle switch or device that provides power to the vehicle
controls that manage REESS operations is set to the activated position.
(e) The REESS is charged with the external charge/discharge
equipment with the maximum charge current specified by the
manufacturer. If the manufacturer does not specify an appropriate
charge current, then a charge rate of \1/3\C is used.
(f) After charging is initiated, the overcurrent specified by the
manufacturer is supplied over the course of 5 seconds from the maximum
charge current level to the over-current level. If the vehicle
manufacturer does not supply an overcurrent level, a 10 Ampere over-
current is supplied over 5 seconds. If charging is not terminated, the
over-current supply is increased in steps of 10 Amperes.
(g) Charging at the over-current level is continued until one of
the following occurs:
(1) The over-current protection control terminates the charge
current; or
(2) The temperature gradient of the REESS is less than 4 [deg]C
through 2 hours from the first overcurrent input.
(h) After the charge current is terminated, if charge and discharge
are permitted by the vehicle controls, a standard cycle is performed in
accordance with S12.6.
(i) After the completion of the standard cycle or if the standard
cycle was not performed, after charging is terminated, the vehicle is
observed for 1 hour for evidence of electrolyte leakage, rupture,
venting, fire, or explosion of the REESS.
(j) At the conclusion of the test, electrical isolation of the
REESS is determined in accordance with S7.2 of this standard.
S12.4 Over-temperature test. The overtemperature test is conducted
at ambient temperatures between 10 [deg]C and 30 [deg]C on a chassis-
dynamometer with the vehicle REESS initially set between 90 to 95
percent SOC. For a vehicle with on-board energy conversion systems such
as an internal combustion engine or a fuel cell, the fuel supply is set
to allow operation for about one hour of driving. The following steps
are conducted to evaluate the vehicle's high temperature protection
controls:
(a) The cooling system of the REESS is disabled using manufacturer
supplied information. For an REESS that will not operate if the cooling
system is disabled, the cooling operation is significantly reduced. If
manufacturer does not supply information to disable or significantly
reduce the cooling system, methods such as crimping the liquid cooling
hose, removing refrigerant fluid, or blocking cabin air intakes for air
cooled REESS are applied.
(b) Temperature probes are connected to the REESS outer casing to
monitor changes in REESS temperature. Temperature measurements may also
be obtained through communication with the REESS control module.
(c) The vehicle is installed on a chassis dynamometer and the
vehicle switch or device that provides power from the REESS to the
electric power train is set to the activated position or the active
driving possible mode.
(d) The vehicle is driven on the dynamometer using an appropriate
vehicle manufacturer supplied drive profile and charging information
for discharge and charge of the REESS to raise the REESS temperature to
its upper boundary safe operating temperature within one hour. If an
appropriate manufacturer-supplied drive profile is not available, the
vehicle is repeatedly accelerated to 80 mph and then decelerated to 15
mph within 40 seconds. If the manufacturer does not supply a charge
profile, then a charge rate greater than \1/3\C current is used.
(e) The discharge/charge procedure on the chassis-dynamometer is
continued until one of the following occurs:
(1) The vehicle terminates the discharge/charge cycle;
(2) The temperature gradient of the REESS is less than 4 [deg]C
through 2 hours from the start of the discharge/charge cycle; or
(3) Three (3) hours have passed since the start of discharge/charge
cycles.
(f) After the discharge and charge procedure is terminated, if
charge and discharge are permitted by the vehicle controls, a standard
cycle is performed in accordance with S12.6.
(g) After the completion of the standard cycle, or if the standard
cycle is not performed, after the discharge and charge procedure is
terminated, the vehicle is observed for 1 hour for evidence of
electrolyte leakage, rupture, venting, fire, or explosion of the REESS.
(h) At the conclusion of the test, electrical isolation of the
REESS is determined in accordance with S7.2 of this standard.
S12.5 External short circuit test. The short circuit test is
conducted at ambient conditions with the vehicle REESS initially set
between 90 to 95 percent SOC. The following steps are conducted to
evaluate the vehicle's external short circuit protection controls:
(a) A breakout harness is connected to the REESS. The manufacturer
must specify an appropriate location(s) and attachment point(s) to
connect the breakout harness.
(b) Temperature probes are connected to the REESS outer casing to
monitor changes in REESS temperature. Temperature measurements may also
be obtained through communication with the REESS control module.
(c) The vehicle switch or device that provides power to the vehicle
controls that manage REESS operations is set to the activated position.
(d) The short circuit contactor (with the contactors in open
position) is connected to the breakout harnesses. The total resistance
of the equipment to create the external short circuit (short circuit
contactor and breakout harnesses) is verified to be between 2 to 5
milliohms.
(e) The short circuit contactor is closed to initiate the short
circuit.
(f) The short circuit condition is continued until one of the
following occurs:
(1) Short circuit current is terminated; or
(2) The temperature gradient of the REESS is less than 4 [deg]C
through 2 hours from the start of initiating the short circuit
condition.
(g) After the short circuit current is terminated, if charge and
discharge are permitted by the vehicle controls, a standard cycle is
performed in accordance with S12.6.
(h) After the completion of the standard cycle, or if the standard
cycle was not performed, after short circuit current is terminated, the
vehicle is observed for 1 hour for evidence of electrolyte leakage,
rupture, venting, fire, or explosion of the REESS.
(i) At the conclusion of the test, electrical isolation of the
REESS is determined in accordance with S7.2 of this standard.
S12.6 Standard cycle. The standard cycle is conducted at ambient
temperatures between 10 [deg]C and 30 [deg]C and starts with a standard
discharge
[[Page 104360]]
followed by a standard charge. The discharge and charge procedures
would follow manufacturer supplied information. The charge procedure is
initiated 15 minutes after discharge is terminated.
(a) If the manufacturer does not provide a discharge procedure, the
vehicle is discharged with 1C current until discharge is terminated by
vehicle controls.
(b) If the manufacturer does not provide a charge procedure, the
vehicle is charged with \1/3\C current until terminated by vehicle
controls.
S13. Warning in the case of thermal event in REESS. The vehicle
shall provide a warning to the driver in the case of a thermal event in
the REESS when the vehicle is in active driving possible mode. The
thermal event warning system must monitor its own readiness. The
warning shall activate within three minutes of the onset of the thermal
event. The warning shall consist of auditory and visual signals that
remain active for at least 5 minutes. For a vehicle with automated
driving systems and without manually operated driving controls, the
visual warning must be provided to all the front row occupants.
S14. Water exposure safety. Each vehicle to which the standard
applies shall maintain electrical isolation as specified in S6.3.1 and
S6.3.2 of this standard at these times:
(a) Just after exposure to water in each of the two tests specified
below and with the vehicle still wet; and
(b) After a minimum of 24 hours after completing each of the tests
specified in S14.1 and S14.2.
S14.1 Vehicle washing test. The vehicle is sprayed from any
direction with a stream of freshwater from a standard test nozzle shown
in figure 9 to this standard that has a nozzle internal diameter of 6.3
millimeters, delivery rate of 11.9 to 13.2 liters/minute, and water
pressure at the nozzle between 30 kPa to 35 kPa.
(a) During the washing, the distance from the nozzle to the vehicle
surface is 3.0 to 3.2 meters. The distance of the nozzle from the
vehicle surface may be reduced, if necessary, to ensure the surface is
wet when spraying upwards. The washing test duration per square meter
of the vehicle surface area is 60 to 75 seconds, with a minimum total
test duration of 3 minutes.
(b) The vehicle external surface, including the vehicle sides,
front, rear, top, and bottom is exposed to the water stream. Border
lines on the vehicle such glass seals, outline of opening parts (doors,
windows, vehicle inlet cover), outline of front grille, and seals of
vehicle lamps are exposed to the water stream from any direction.
(c) At the conclusion of the normal washing test, with the vehicle
still wet, electrical isolation is determined in accordance with S7.2
of this standard.
S14.2 Driving through standing water test. The vehicle is driven
through a wade pool of at least 10 centimeters but not more than 15
centimeters depth of freshwater for a distance of 500 meters at a
minimum speed of 12 mph (20 km/h) but not more than 15 mph (24 km/h).
(a) If the wade pool is less than 500 m in length, then the vehicle
shall be driven through it several times for a total distance of 500 m.
The total time, including the period outside of the wade pool, shall be
less than 10 minutes.
(b) At the conclusion of the standing water test, with the vehicle
still wet, electrical isolation is determined in accordance with S7.2
of this standard.
Figures to FMVSS No. 305a
[GRAPHIC] [TIFF OMITTED] TR20DE24.000
Figure 1. Voltage Measurements of the High Voltage Source
[[Page 104361]]
[GRAPHIC] [TIFF OMITTED] TR20DE24.001
Figure 2. Measurement for V1 Voltage Between the Negative Side of the
High Voltage Source and the Electrical Chassis
[GRAPHIC] [TIFF OMITTED] TR20DE24.002
Figure 3. Measurement for V2 Voltage Between the Positive Side of the
High Voltage Source and the Electrical Chassis
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Figure 4. Measurement for V1' Voltage Across Resistor Between Negative
Side of the High Voltage Source and Electrical Chassis
[GRAPHIC] [TIFF OMITTED] TR20DE24.004
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Figure 5. Measurement for V2' Voltage Across Resistor Between Positive
Side of the High Voltage Source and Electrical Chassis
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Figure 6. Marking of High Voltage Sources
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Figure 7a. Access Probes for the Tests of Direct Contact Protection.
Access Probe IPXXB (Top) and Access Probe IPXXD (Bottom)
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Figure 7b. Jointed Test Finger IPXXB
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Figure 8. Connection To Determine Resistance Between Exposed Conductive
Parts of Electrical Protection Barrier and Electrical Chassis
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Figure 9. Standard Nozzle for IPX5 Water Exposure Test
Issued in Washington, DC, under authority delegated in 49 CFR
1.95 and 501.
Adam Raviv,
Chief Counsel.
[FR Doc. 2024-28707 Filed 12-19-24; 8:45 am]
BILLING CODE 4910-59-P