The National Highway Traffic Safety Administration (NHTSA) Issue a Notice of Proposed Rulemaking (NPRM) for a New Federal Motor Vehicle Standard (FMVSS) for Electric Vehicles (EVs)

The National Highway Traffic Safety Administration (NHTSA) published a Notice of Proposed Rulemaking (NPRM) in the April 15, 2024 Federal Register (F.R. Vol. 89 No. 73; NHTSA-2024-0012).This NPRM includes a new Standard - FMVSS 305a - Electric-Powered Vehicles: Electric Powertrain Integrity; Global Technical Regulation (GTR) 20, Incorporation by Reference. FMVSS 305a to replace FMVSS 305 - Electric-powered Vehicles: Electrolyte Spillage and Electrical Shock Protection.

Among other improvements, FMVSS 305a includes:

• Applies to light and heavy vehicles

• Provides performance and risk mitigation requirements for the propulsion battery

• Addresses National Transportation Safety Board (NTSB) recommendations

• Requires manufacturers to submit standardized emergency response information for inclusion on NHTSA's website for first and second responders.

FMVSS 305 only applies to passenger cars and to multipurpose passenger vehicles, trucks, and buses with a GVWR of 4,536kg (10,000lb) or less. Consistent with GTR 20, proposed FMVSS 305a expands the applicability to vehicles with a GVWR greater than 4,536kg (10,000lb). Under proposed FMVSS 305a: Light vehicles would be subject to requirements carried over from FMVSS 305 that ensure the safety of the electrical system during normal vehicle operations and after a crash, as well as to new requirements for the Rechargeable Electrical Energy Storage System (REESS).

Heavy vehicles would 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 would not be subject to post-crash requirements. This proposed exclusion of heavy vehicles, other than school buses, from crash tests, aligns with similar exclusions in FMVSS 301 - Fuel System Integrity for conventional fuel vehicles and FMVSS 303 - Fuel System Integrity of compressed natural gas vehicles. Heavy school buses would be subject to the requirements for electrical system safety during normal vehicle operations and to the requirements for the REESS, and would 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 301 for heavy school buses (impacted at any point and at any angle by a moving contoured barrier).

The requirements for REESS retention and electrolyte leakage are already in FMVSS 305, but this NPRM proposes to enhance some provisions consistent with GTR 20. Current FMVSS 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, NHTSA is proposing to prohibit fire or explosion for a one-hour post-test period. FMVSS 305 already includes the first three compliance options for electrical shock protection, but not the low energy option that is available for capacitors in GTR 20. This NPRM would complete the alignment by proposing the low energy option for capacitors in FMVSS 305a.

As part of NHTSA's battery initiative, and in response to 2020 NTSB recommendations, this NPRM proposes to include in FMVSS 305a 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 would 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.

Current FMVSS 305 does not apply to vehicles that travel under 40km/h (25mph), such as low-speed vehicles. Given there are low-speed vehicles that are also electric-powered vehicles, NHTSA requests comments on the possibility of applying aspects of FMVSS 305a to low-speed vehicles to ensure a level of protection against shock and fire, particularly during normal vehicle operation, and to assure the safe operation of the REESS.

Throughout the NPRM the NHTSA requested comments on other particular items. Here are some of the specific requests:

• There are currently no full vehicle crash tests in FMVSSs for heavy vehicles other than heavy school buses. NHTSA seeks comment on a mechanical integrity test for REESS on heavy vehicles to evaluate post-crash safety at a component-level. Additionally, they seek comment on the parameters for a possible quasi-static crush test for the REESS on heavy vehicles.

• NHTSA seeks comments to supplement their research on a mechanical shock test for REESS on heavy vehicles to evaluate post-crash safety at a component level. The aim of the mechanical shock requirement in GTR 20 is to verify the safety performance of the REESS under inertial loads which may occur during an impact. The requirement evaluates the performance of the REESS mountings and fixtures to the vehicle.

• NHTSA seeks comments regarding the best approach or test method for evaluating post-crash safety for electric vehicles with a GVWR greater than 4,536kg (10,000lb). Specifically, NHTSA seeks information and recommendations on other applicable safety tests and corresponding objective performance criteria to evaluate the propulsion system crash safety performance of vehicles with a GVWR greater than 4,536kg (10,000lb).

• NHTSA seeks thoughts on the inclusion of a post-crash electrolyte leakage requirement in FMVSS 305a and the necessity and relevance of such a requirement for current EVs. Specifically, NHTSA asks whether this requirement is still relevant given today's propulsion battery technologies and based on the safety incidents observed in the field or in crash tests, if it is still necessary. NHTSA seeks comment on whether a 5-liter maximum amount of electrolyte permitted to be leaked is still relevant and requests commenters to provide data based on safety incidents observed in the field or in crash tests to substantiate their assertions. NHTSA seeks thoughts on and recommendations regarding electrolyte leakage detection methods and how these detection methods can discern between the presence of electrolyte and the presence of other liquids such as coolant.

• NHTSA agrees with GTR 20 that there is a safety need for low temperature protections for the REESS and is proposing to require manufacturers to submit documentation to NHTSA about pertinent low temperature safety hazards, describe their risk mitigation strategies for the safety hazards, and how they assessed the effectiveness of their mitigation strategies.

• NHTSA generally agrees that a documentation approach on risk mitigation strategies currently has merit, given there is no suitable performance test to validate mitigation or prevention of Single-Cell Thermal Runaway (SCTR) within a REESS. NHTSA is proposing a documentation approach based on GTR 20 but has focused the GTR's requirements to better address this safety need pending development of an objective performance test that can be applied to all REESSs in vehicles. NHTSA requests comments on whether the proposed document requirement would be better placed in a general agency regulation than in proposed FMVSS 305a.

• In the absence of information enabling NHTSA to propose a practical test procedure to evaluate the performance of a visual warning, the documentation approach ensures that manufacturers are aware of the safety risks at issue and have considered ways to address the risks.

• The agency seeks comment on test conditions and test procedures that would address observed safety risks associated with water submersion of REESS and high voltage components.

• There are several GTR 20 provisions for REESS performance during normal vehicle operations that NHTSA has not included in this NPRM. These provisions relate to requirements for: vibration, thermal shock and cycling, fire resistance, and low state-of-charge (SOC). NHTSA listed a description of the requirements and explanations of why NHTSA is proposing not to include the requirements. NHTSA requests comments on these views.

• The agency seeks public comment on the safety need of a REESS thermal shock and cycling requirement, and requests commenters provide data to substantiate their comments and/or assertions.

• GTR20 requires a telltale to the driver in the event of low REESS State of Charge (SOC). The agency is tentatively not including this telltale requirement for electric powered vehicles. NHTSA seeks comment on whether this GTR 20 requirement should be incorporated into proposed FMVSS 305a, and if yes, what the telltale should look like.

• There are low-speed vehicles that are also electric-powered vehicles. NHTSA requests comments on applying aspects of FMVSS 305a to low-speed vehicles to ensure a level of protection against shock and fire, particularly during normal vehicle operation, and to assure the safe operation of the REESS. The agency requests comments, including any supporting research on low-speed vehicles.

• NHTSA's intent is to have both ERGs and rescue sheets accessible in a centralized NHTSA web location. NHTSA requests comments on whether electric vehicle ERGs and rescue sheets that were previously hosted on the National Fire Protection Association (NFPA) website should be included in NHTSA's centralized web location.

• Since the documentation specifications are more akin to a disclosure requirement (disclosing information to NHTSA) than a performance test or a consumer safety information requirement, NHTSA asks whether the proposed emergency response information requirements would be better placed in a general agency regulation than in proposed FMVSS 305a.

• NHTSA also seeks comments on whether the proposed risk mitigation documentation requirements would be better placed in a general agency regulation. This NPRM proposes manufacturers to document and submit information, upon request, describing identified safety risks, risk mitigation strategies, and validation of those strategies. NHTSA has similar documentation requirements in FMVSS 126 - Electronic stability control systems for light vehicles and FMVSS 226- Ejection Mitigation. NHTSA requests comments on the pros and cons of placing the proposed risk mitigation documentation requirement in a regulation rather than in FMVSS 305a.

• NHTSA seeks comment on the proposed reporting requirements to mitigate the risk of SCTR due to an internal short-circuit in a single cell of the REESS and the performance test under consideration in GTR 20 Phase 2.

• Comments are requested on the pros and cons of placing the requirement for providing ERG and rescue sheets to NHTSA to be in a regulation rather than in FMVSS 305a.

Comments regarding this NPRM need to be submitted by June 14, 2024.The compliance date for these actions is intended to be two years after publication of the Final Rule (FR) in the Federal Register. Small-volume manufacturers, final-stage manufacturers, and alterers would be provided an additional year to comply with the Final Rule. NHTSA proposes to permit optional early compliance. After FMVSS 305a is finalized, NHTSA intends to sunset FMVSS 305.

The NPRM is available on InterRegs.NET for our US Federal subscribers and is also available on SelectRegs.