Document ID: NHTSA-2011-0107-0001
Agency: nhtsa
Document Type: Rule
Title: Federal Motor Vehicle Safety Standards: Electric-Powered Vehicles; Electrolyte Spillage and Electrical Shock Protection
Posted Date: 2011-07-29T04:00Z

[Federal Register Volume 76, Number 146 (Friday, July 29, 2011)]
[Rules and Regulations]
[Pages 45436-45453]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-19216]

[[Page 45436]]

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DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Part 571

[Docket No. NHTSA-2011-0107]
RIN 2127-AK80

Federal Motor Vehicle Safety Standards; Electric-Powered 
Vehicles; Electrolyte Spillage and Electrical Shock Protection

AGENCY: National Highway Traffic Safety Administration (NHTSA), 
Department of Transportation (DOT).

ACTION: Final rule; response to petitions for reconsideration.

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SUMMARY: This document responds to petitions for reconsideration of a 
final rule issued by this agency on June 14, 2010. This final rule 
amended the electrical shock protection requirements to facilitate the 
development and introduction of fuel cell vehicles (a type of electric-
powered vehicle) and the next generation of hybrid and battery electric 
powered vehicles. This document addresses issues raised in the 
petitions for reconsideration relating to the scope and applicability 
of the standard, the definitions in the standard, the retention 
requirements for electric energy storage/conversion systems, the 
electrical isolation requirements, the test specifications and 
requirements for electrical isolation monitoring, the state-of-charge 
of electric energy storage devices prior to the crash tests, a proposed 
protective barrier compliance option for electrical safety, the use of 
alternative gas to crash test hydrogen fuel cell vehicles, and a 
proposed low-energy compliance option for electrical safety.

DATES: The effective date of this final rule is September 1, 2011 with 
optional early compliance.
    Petitions for reconsideration: Petitions for reconsideration of 
this final rule must be received not later than September 12, 2011.

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., Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: For technical issues: Ms. Shashi 
Kuppa, Office of Crashworthiness Standards (telephone: 202-366-3827) 
(fax: 202-493-2990), NVS-113.
    For legal issues: Mr. Jesse Chang, Office of the Chief Counsel 
(telephone: 202-366-2992) (fax: 202-366-3820), NCC-112.
    The mailing address for these officials is: National Highway 
Traffic Safety Administration, 1200 New Jersey Avenue, SE., Washington, 
DC 20590.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Background--June 14, 2010 Final Rule
II. Petitions for Reconsideration
III. Summary of Revisions to the June 14, 2010 Final Rule
IV. Agency Response and Rationale
    a. Application
    b. Definitions
    c. Electric Energy Storage/Conversion System Retention
    d. Electrical Safety
    e. Electrical Isolation Monitoring
    f. Electric Energy Storage Device State-of-Charge
    g. Physical Barrier Compliance Option for Electrical Safety
    h. Use of Alternative Gas for Testing Hydrogen Fuel Cell 
Vehicles
    i. Low-Energy Compliance Option for Electrical Safety
V. Rulemaking Analyses and Notices
VI. Regulatory Text

I. Background--June 14, 2010 Final Rule

    On June 14, 2010, NHTSA issued a final rule which amended the 
electrical shock protection requirements of Federal Motor Vehicle 
Safety Standard (FMVSS) No. 305, ``Electric-powered vehicles; 
electrolyte spillage and electrical shock protection,'' to facilitate 
the development and introduction of fuel cell vehicles, a type of 
electric-powered vehicle, and the next generation of hybrid and battery 
electric powered vehicles (75 FR 33515, NHTSA Docket No. 2010-0021). 
The final rule revised the agency's standard regulating electrolyte 
spillage and electrical shock protection for electric-powered vehicles 
to align it more closely with the April 2005 version of the Society of 
Automotive Engineers (SAE) J1766--``Recommended Practice for Electric 
and Hybrid Electric Vehicle Battery Systems Crash Integrity Testing.''
    This rule also provided greater flexibility by allowing 
manufacturers to meet the requirements of FMVSS No. 305 by designing 
their electrically powered vehicles so that, in the event of a crash, 
the electric energy storage, conversion, and propulsion systems are 
either electrically isolated from the vehicle's chassis or their 
voltage is below specified levels considered safe from electric shock 
hazards. Since the physiological impacts of direct current (DC) are 
less than those of alternating current (AC), the final rule specified 
lower electrical isolation requirements for certain DC components (100 
ohms/volt) than for AC components (500 ohms/volt).
    In addition, the final rule included new definitions, made changes 
to existing definitions of terms used in the standard, changed the 
energy storage/conversion device retention requirements, specified a 
low voltage option for achieving electrical safety, and required 
monitoring of the isolation resistance of DC high voltage sources that 
comply with the 100 ohms/volt electrical isolation requirement. The 
agency also established an effective date on September 1 in the year 
after the final rule was published (or September 1, 2011) with optional 
early compliance.

II. Petitions for Reconsideration

    Subsequently, NHTSA received petitions for reconsideration of the 
June 14, 2010 final rule from the Alliance of Automobile Manufacturers 
(Alliance),\1\ Technical Affairs Committee of the Association of 
International Automobile Manufacturers, Inc. (AIAM) \2\ and Honda Motor 
Co., Ltd. (Honda). Ford Motor Company (Ford) also presented an analysis 
to the agency in support of the Alliance's petition for reconsideration 
regarding the issue of electric energy storage system state-of-charge 
prior to the crash tests specified in the standard.\3\ In addition, on 
December 21, 2010, the Alliance, AIAM, and Honda submitted a joint 
letter as supplementary information to their petitions for 
reconsideration stating their support for the definitions used in the 
draft documents on electrical safety for a forthcoming global technical 
regulation (GTR) on hydrogen fuel cell vehicle safety.
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    \1\ The Alliance is a trade association whose members are: BMW 
Group, Chrysler Group LLC, Ford Motor Company, General Motors LLC, 
Jaguar Land Rover, Mazda, Mercedes-Benz USA, Mitsubishi Motors, 
Porsche, Toyota, and Volkswagen.
    \2\ The AIAM petition stated it is a trade association whose 
Technical Affairs Committee members include: American Honda Motor 
Co., American Suzuki Motor Corp., Aston Martin Lagonda of North 
America, Inc., Ferrari North America, Inc., Hyundai Motor America, 
Isuzu Motors America LLC, Kia Motors America, Inc., Mahindra & 
Mahindra Ltd., Maserati North America, Inc., McLaren Automotive 
Ltd., Nissan North America, Inc., Peugeot Motors of America, Subaru 
of America, ADVICS North America, Inc., Delphi Corporation, Denso 
International America, Inc., and Robert Bosch Corporation. In 
January 2011, AIAM was renamed as the Association of Global 
Automakers (Global Automakers). Nonetheless, our response to 
petitions of the final rule will still refer to AIAM.
    \3\ Ford presented an analysis of the state-of-charge of the 
energy storage system prior to the crash tests in a meeting with 
NHTSA personnel on May 26, 2010. This presentation was posted to the 
Docket No. NHTSA-2010-0021 on September 1, 2010.
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    The petitioners generally sought increased clarity by raising 
issues

[[Page 45437]]

regarding the definitions, test specifications, and performance 
requirements in this rule. Specifically, the petitioners raised 
questions regarding the applicability and scope of the standard, the 
definitions of terms used, the electric energy storage/conversion 
system retention requirements, the electrical isolation requirements, 
the requirements and test specifications for electrical isolation 
monitoring systems, the electric energy storage device state-of-charge, 
the protective barrier as a compliance option for electrical safety, 
and the use of alternative gas for testing hydrogen fuel cell vehicles.

III. Summary of Revisions to the June 14, 2010 Final Rule

    This document responds to all the petitions for reconsideration of 
the June 14, 2010 final rule. Specifically, this final rule makes the 
following changes to the June 14, 2010 final rule:
     Revises the ``Application'' section to indicate that the 
standard applies only to vehicles that use high voltage electrical 
components for propulsion power rather than to any vehicle that has 
high voltage electrical components.
     Clarifies the definitions used in the June 14, 2010 final 
rule for electrical isolation, electric energy storage/conversion 
system, electric energy storage device, propulsion system, and high 
voltage source.
     Adds further clarity by including new definitions for 
automatic disconnect, electric energy storage/conversion device, 
electrical chassis, and electric power train.
     Revises the application of retention requirements from 
energy storage/conversion ``systems'' to energy storage/conversion 
``devices.''
     Clarifies the electric energy storage/conversion device 
retention requirements to indicate that during and after the test, the 
device(s) 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 those located outside the 
occupant compartment shall not enter the occupant compartment.
     Clarifies the electrical safety requirements to specify 
that AC high voltage sources with electrical isolation monitoring 
require 500 ohms/volt electrical isolation.
     Specifies the voltage measurement locations for high 
voltage sources with and without automatic disconnects in the test 
procedures for determining electrical safety.
     Revises the electrical isolation monitoring requirement by 
deleting the term ``continuous'' in ``continuous monitoring'' and 
including a range in resistance of the external resistor selected in 
the test procedure to evaluate the performance of the monitoring 
system.
     Clarifies the specification for the state-of-charge of 
electric energy storage devices before the crash tests to be 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 permanently affixed to the vehicle, or at 95 
percent of the maximum capacity of the electric energy storage device 
if no such recommendation is made.
     Revises the regulatory text and Figures 1-5 to utilize the 
new terms added to the definitions section.

IV. Agency Response and Rationale

    After reviewing the petitions for reconsideration, NHTSA is 
responding to each issue raised by the petitioners as follows.

a. Application

    The June 14, 2010 final rule defined the scope of FMVSS No. 305 by 
stating the following in paragraph S3 Application:

    S3. Application. This standard applies to passenger cars, and to 
multipurpose passenger vehicles, trucks, and buses that have a GVWR 
of 4,536 kg or less, that use electrical components with working 
voltages more 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.

    Both the Alliance and the AIAM noted that in section ``S3 
Application'' of the final rule, the agency omitted the word 
``propulsion'' and that this was not consistent with the language in 
the NPRM.\4\ Both organizations argued that the omission of the word 
``propulsion'' could be interpreted to encompass all electrical systems 
that are not within the scope of FMVSS No. 305 (e.g. high intensity 
discharge (HID) headlamps, engine ignition systems, fuel injectors, 
etc).
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    \4\ 72 FR 57266; Notice of Proposed Rulemaking; October 9, 2007.
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    The Alliance proposed that the scope be remedied by adding the word 
``propulsion'' in the application section, S3. The AIAM indicated in 
its petition that it supported the language proposed by the Alliance. 
The language proposed by the Alliance is as follows:

    S3 Application. This standard applies to passenger cars, and to 
multipurpose passenger vehicles, trucks and buses with a GVWR of 
4536 kg or less, that use electrical propulsion components with 
working voltages more 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. 
(emphasis in the original)

    NHTSA's Response: We agree with the Alliance that by omitting the 
word ``propulsion'' in S3 of the final rule, the standard encompasses 
vehicles and electrical systems that were not intended for application 
of FMVSS No. 305. Since the agency is not aware of any cases of 
injuries/fatalities from shock in non-electrically powered vehicles 
with other high voltage components such as HID headlamps, ignition 
systems, or fuel injectors, this final rule adopts the language for S3 
Application as proposed by the Alliance. This new version of the 
regulatory text ensures that FMVSS No. 305 will not extend to the 
aforementioned vehicles and vehicle components for which the standard 
was not intended to apply.

b. Definitions

    The June 14, 2010 final rule adopted new definitions into FMVSS No. 
305. In a joint letter submitted by the Alliance, AIAM, and Honda, the 
organizations acknowledged that while the current FMVSS No. 305 
definitions were based on SAE J1766, the subsequent promulgation of 
FMVSS No. 305 and the development of an international GTR on hydrogen 
fuel cell vehicle safety have largely rendered aspects of the SAE 
standard obsolete. The organizations requested that the agency 
incorporate, into FMVSS No. 305, the definitions contained in the draft 
electrical safety requirements developed by the Electric Safety (ELSA) 
working group in September 2010 as part of the draft GTR. Given this 
request from the aforementioned organizations, the rapid development of 
technology in electrical and fuel cell vehicles resulting in numerous 
changes in terminology and their associated definitions, and 
significant uncertainty among the relevant stakeholders as to the 
proper interpretation of many of the definitions adopted by the June 
14, 2010 final rule, today's final rule seeks to clarify and update 
many of the definitions through additional language and/or adopting 
similar language from the draft ELSA electrical safety document 
(henceforth referred to as the ELSA document) where appropriate.\5\ In 
the following

[[Page 45438]]

sections, we will address each of the definitions added or amended by 
today's final rule in turn.
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    \5\ Electrical Safety Provisions for Vehicles Post Crash ELSA-8-
05 Rev. 01 (Draft agreed during 8th ELSA Meeting, Aug 31-Sept 2, 
2010) http://www.unece.org/trans/doc/2010/wp29grsp/ELSA-8-05r1e.pdf.
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1. Automatic Disconnect
    One appropriate area for adopting similar language from the ELSA 
document is the definition for ``automatic disconnect.'' Since the June 
14, 2010 final rule did not define ``automatic disconnect,'' the agency 
is concerned that it may result in ambiguity regarding the location of 
voltage measurements taken pursuant to paragraph S7.6.1 (as further 
discussed later in this document). Therefore, today's final rule 
includes a definition for automatic disconnect, derived from the ELSA 
document, which states that ``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.
2. Electrical Isolation
    In the final rule, we defined ``Electrical isolation'' as ``the 
electrical resistance between the vehicle high voltage source and any 
vehicle conductive structure.'' The Alliance stated that the definition 
for ``electrical isolation'' as defined in the final rule could present 
difficulties because ``any vehicle conductive structure'' could be 
interpreted to include the high voltage source itself, and a high 
voltage source cannot be isolated from itself. The Alliance, therefore, 
petitioned to revise the definition so that the electrical isolation is 
between the vehicle high voltage source and the ``vehicle chassis 
electricity-conducting structure.''
    NHTSA's Response: The agency agrees that that the language ``any 
conductive structure'' should be clarified to indicate which vehicle 
components are required to be isolated from the high voltage source. 
However, we decline to adopt the Alliance's proposed term, ``vehicle 
chassis electricity-conducting structure,'' since it also lacks 
sufficient clarification on which vehicle components will be included 
by this term. For example, it is unclear whether the term includes 
other conducting structures in the vehicle such as the enclosures of 
high voltage sources. To address this issue, this final rule clarifies 
what the high voltage source is electrically isolated from by including 
a definition for a new term that has been proposed in the draft ELSA 
document. Based on the language of the ELSA document, a definition for 
``electrical chassis'' is included in today's final rule as follows:

    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.

    Since this definition of electrical chassis includes vehicle 
designs with multiple electrical chassis, this final rule clarifies the 
definition of electrical isolation to mean the electrical resistance 
between a given high voltage source and any electrical chassis of the 
vehicle. Further, in order to be consistent with the manner in which 
electrical isolation is determined in S7.6.6 and S7.6.7 of the 
electrical isolation test procedure and with the units of electrical 
isolation specified in S5.3(a), today's final rule also clarifies the 
definition of electrical isolation of a high voltage source to mean the 
electrical isolation resistance of the high voltage source divided by 
the working voltage of the high voltage source. Applying these 
corrections, along with the new definition of electrical chassis, 
today's final rule amends the definition for electrical isolation to 
read as follows:

    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.

    The agency believes the changes made in today's final rule address 
the Alliance's concern about the broad term ``any vehicle conductive 
structure.'' Specifically, this definition ensures that the term 
``vehicle conductive structure'' is not construed to include the high 
voltage source itself as the new definition for ``electrical chassis'' 
explicitly excludes high voltage sources. In addition, the use of these 
definitions more closely aligns FMVSS No. 305 with the definitions 
proposed by the ELSA working group and clarifies what types of 
components would be considered part of the chassis. For example, under 
these definitions, the electrical chassis includes the enclosures of 
the high voltage sources which are conductively linked to other 
conductive parts of the vehicle whose electrical potential is taken as 
a reference.
3. Electric Energy Storage/Conversion/Power Generating System & 
Electric Energy Storage Device
    Before the NPRM in this current rulemaking, FMVSS No. 305 contained 
a definition for the term ``Battery system component.'' In the NPRM, 
the agency proposed replacing the definition of ``Battery system 
component'' with ``Energy storage system.'' The agency changed the 
definition in the final rule after considering the joint Alliance/AIAM 
comment to the NPRM to include ``energy conversion system'' as part of 
the definition for ``Energy storage system.'' In their comment, the 
Alliance/AIAM stated that fuel cell systems were conversion systems and 
should also comply with the retention requirements. NHTSA agreed and 
redefined ``Energy storage system'' as ``Electric energy storage/
conversion/power generating system.'' The term ``power generating 
system'' was also included to align FMVSS No. 305 more closely with the 
terminology used in SAE J1766. Thus, the June 14, 2010 final rule 
defined ``Electric Energy Storage/Conversion/Power Generating System'' 
as follows:

    Electric energy storage/conversion/power generating system means 
the components comprising, but not limited to, the vehicle's high 
voltage battery system, capacitor system, or fuel cell system, and 
rechargeable energy storage systems. These include, but are not 
limited to, the battery or capacitor modules, interconnects, venting 
systems, battery or capacitor restraint devices, and electric energy 
storage boxes or containers that hold the individual battery or 
capacitor modules. Hydrogen system components of fuel cell vehicles, 
such as the hydrogen tanks and hydrogen tubes, are not included in 
the electric energy storage/conversion system.

    We received multiple petitions requesting that the agency 
reconsider the ``Electric energy storage/conversion/power generating 
system'' definition. The Alliance stated that this definition is overly 
broad and includes energy storage systems beyond those used for 
propulsion power. The Alliance recommended that the definition be 
modified to utilize the following text: Electric energy storage/
conversion/power generating system ``means the electric energy sources 
for the propulsion system comprising, but not limited to, the vehicle's 
high voltage battery system * * *'' (emphasis in original).
    The AIAM and Honda had further concerns about the definition. The 
AIAM stated that the definition is not used consistently throughout the 
standard or even within the definition itself. For example, the AIAM 
noted that the last sentence of the definition for electrical energy 
storage/conversion/power generating system (which refers to hydrogen 
system components of fuel cell vehicles) is only applicable to the 
electric energy storage or conversion system parts of the definition 
and not to the power generating system portion. Honda stated that the 
combined definition may cause confusion to the reader.
    Further, both the AIAM and Honda stated that various requirements 
in

[[Page 45439]]

FMVSS No. 305 apply only to portions of the electric energy storage/
conversion/power generating system definition, creating confusion 
regarding the applicability of various requirements in the standard. 
The AIAM and Honda refer to fuel cell modules as an example of this 
potential confusion. They noted that the retention requirements in 
S5.2, as written, are applicable only to the electric energy storage 
system and electric energy conversion system but are not applicable to 
the electric power generating system. According to SAE J1766 (April, 
2005), the term ``power generating system components'' is defined as 
``the components comprising the high voltage power generating system in 
an Electric, Fuel Cell or Hybrid vehicle. These include, but are not 
limited to, generators, fuel cell modules, DC/DC converters and 
interconnects.'' The AIAM and Honda stated that if the SAE definition 
is used to determine the meaning of ``power generating system'' for 
purposes of S5.2 retention requirements, it could be concluded that 
fuel cell modules are exempt because S5.2 does not list ``power 
generating system'' as requiring compliance with the retention 
requirements. The AIAM and Honda do not believe that the agency 
intended to exclude fuel cell modules from the retention requirements, 
considering the potential occupant injury risk in a crash if fuel cell 
modules became unattached. For clarity, both the AIAM and Honda 
petitioned that the terms ``Electric energy storage system,'' 
``Electric energy conversion system'' and ``Electric power generating 
system'' be defined separately.
    NHTSA's Response: We agree with petitioners that the ``Electric 
energy storage/conversion/power generating system'' definition should 
be clarified in order to avoid confusion as to the applicability of 
various requirements in FMVSS No. 305. In order to accomplish this 
task, today's final rule utilizes three separate definitions. First, it 
renames and makes adjustments to the language in the ``Electric energy 
storage/conversion/power generating system'' definition in order to 
reference the components that comprise the entire ``Electric energy 
storage/conversion system.'' Second, today's final rule also adds a new 
definition for ``Electric energy storage/conversion device'' in order 
to help distinguish the instances in which the various requirements of 
FMVSS No. 305 are to apply to an entire system as opposed to only 
component devices. Finally, this rule also retains the ``Electric 
energy storage device'' definition with minor revisions in order to 
clarify the instances in which the test specifications of this rule 
apply to the electric energy storage devices alone.
    The agency also agrees with the Alliance petition that the 
definition for ``electric energy storage/conversion/power generating 
system'' should be specific to systems used for vehicle propulsion in 
order to distinguish them from other electric energy storage systems 
such as the auxiliary battery that is present on many hybrid/electric 
vehicles and is currently not subject to the retention requirements 
since it is typically of low mass and does not pose a safety hazard in 
the existing fleet. Thus, we have made the appropriate modifications to 
the three aforementioned definitions to indicate that the devices or 
components covered by each definition are used for vehicle propulsion.
    In order to further add clarity to this definition, this final rule 
removes the reference to the term, ``power generating systems,'' from 
the June 14, 2010 final rule definition of ``Electric energy storage/
conversion/power generating system.'' As ``power generating systems'' 
was included in the June 14, 2010 final rule definition in order to 
more closely align FMVSS No. 305 with the (now obsolete) SAE Standard 
J1766, the agency believes that there is no longer a purpose for 
including ``power generating systems'' in the ``Electric energy 
storage/conversion/power generating system'' definition. Thus, today's 
final rule simply defines ``Electric energy storage/conversion 
system.''
    In addition, we agree with the AIAM that the last sentence of the 
``Electric energy storage/conversion/power generating system'' 
definition in the June 14, 2010 final rule can cause confusion. We 
believe that the last sentence of that definition, which states that 
``[h]ydrogen system components of fuel cell vehicles, such as the 
hydrogen tanks and hydrogen tubes, are not included in the electric 
energy storage/conversion system,'' is superfluous. Thus, in further 
advancing the goal of clarity in the ``Electric energy storage/
conversion system'' definition, we have deleted the aforementioned 
sentence. Under the definition in today's final rule, fuel cells are a 
type of energy conversion system and the agency will continue to refer 
to high voltage batteries, capacitors, and fuel cell systems as 
``energy storage/conversion systems.''
    Thus, the final rule defines ``Electric energy storage/conversion 
system'' as follows:

    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.

    Additionally, today's final rule adds a new definition for 
``Electric energy storage/conversion device.'' We take note that the 
retention requirements of S5.2 of the June 14, 2010 final rule apply to 
all components that fall under the broader ``Electric energy storage/
conversion system'' definition and that petitioners asked for 
clarification to the ``Electric energy storage/conversion system'' 
definition, in part, to clarify the specific components that will be 
subject to the retention requirements of paragraph S5.2. As further 
discussed later in this document, petitioners are concerned that 
``energy storage/conversion systems'' can include interconnects and 
venting systems that are typically of low mass and need not be included 
in the retention requirements because they are not a safety risk. Thus, 
to make this distinction, today's final rule modifies paragraph S5.2 to 
utilize the definition for ``electric energy storage/conversion 
device'' and defines this term as follows:

    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.

    Today's final rule also retains and amends the definition of 
``Electric energy storage device'' from the June 14, 2010 final rule. 
The June 14, 2010 final rule defined ``Electric energy storage device'' 
as follows:

    Electric energy storage device means a high voltage source that 
can store energy, such as a battery or capacitor modules.

    The term, ``Electric energy storage device,'' is used in the 
regulatory text to specify the state of charge of electric energy 
storage devices before the vehicle crash test. While closely related to 
the term ``Electric energy storage/conversion device,'' it does not 
encompass conversion devices such as fuel cell stacks. Today's final 
rule makes minor revisions to this definition in order to add clarity 
and consistency with the two other definitions discussed in this 
section by specifying that the electric energy storage devices under 
consideration are used for vehicle propulsion. Thus, the definition of 
electric energy storage device in today's final rule is amended as 
follows:

[[Page 45440]]

    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.

    Paragraphs S1 and S2 of today's final rule have also been amended 
to reflect these new definitions.
4. High Voltage Source
    The June 14, 2010 final rule included a definition of ``high 
voltage source'' which is reproduced below:

    High voltage source means any electric component that has a 
working voltage greater than 30 VAC or 60 VDC.

    The Alliance stated that in common usage, a ``voltage source'' is a 
component capable of generating or storing electrical potential energy. 
It argued that under the current definition, connectors and wiring 
could be construed as voltage sources even though they are not capable 
of generating or storing electrical energy. The Alliance petitioned 
that the definition of ``high voltage source'' be revised to include 
``any electric component that is capable of generating or storing a 
voltage greater than 30 VAC or 60 VDC.''
    NHTSA's Response: We agree with the Alliance that the current 
definition of ``high voltage source'' should be clarified. However, we 
cannot agree with the petitioner's proposal to limit the definition of 
high voltage sources to only those components that are capable of 
generating or storing electrical energy. Through the definition 
included in the June 14, 2010 final rule, the agency did intend to 
apply the electrical safety requirements to high voltage components, 
including wiring and connectors that are part of the vehicle's electric 
power train to ensure comprehensive electric shock protection.
    However, we acknowledge that the definition in the June 14, 2010 
final rule may not sufficiently distinguish the components included by 
the ``high voltage source'' definition from those that are not 
included. To clarify our intent today's final rule defines a high 
voltage source as ``any electric component contained in the electric 
power train or conductively connected to the electric power train that 
has a working voltage greater than 30 VAC or 60 VDC (emphasis added).''
    To further clarify this new definition, today's final rule adds a 
definition for ``electric power train'' stating that it refers to ``an 
assembly of electrically connected components which includes, but is 
not limited to, electric energy storage/conversion systems and 
propulsion systems.'' The definition of ``electrical energy storage/
conversion system'' is updated as described above. Further, today's 
final rule makes minor revisions to the definition of ``propulsion 
system'' to mean ``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, electronic controllers, and 
associated wire harnesses and connectors, and coupling systems for 
charging rechargeable energy storage systems.''
    These definitions adopt similar language from the Definitions and 
the General sections of the ELSA document in order to both address the 
Alliance, AIAM and Honda's suggestion that the agency adopt the ELSA 
definitions where appropriate and to more clearly define the components 
that are included under the definition of ``high voltage source.''

c. Electric Energy Storage/Conversion System Retention

    In the NPRM, NHTSA proposed adjusting the ``Battery retention'' 
requirements of paragraph S5.2 to properly reflect the additional 
energy storage devices that the updated standard intended to cover. The 
adjustment to paragraph S5.2 accomplished this goal by proposing to 
replace the word ``battery'' with the words ``energy storage device'' 
in S5.2 and adjust other portions of the regulatory text accordingly.
    In the final rule, we amended the regulatory text based on the 
considerations in the NPRM and in response to additional information 
from a March 9, 2009 interpretation request from Hyundai. Hyundai 
stated that the requirements of S5.2 allowed a battery module located 
outside the passenger compartment to become dislodged as long as it 
does not enter the occupant compartment, while a module that is located 
within the occupant compartment must simply remain in the location in 
which it is installed. Hyundai stated that this may not properly 
address the intent of the standard in some circumstances.\6\ It argued 
that in vehicles such as sport utility vehicles (SUV) or station 
wagons, a battery module located inside the occupant compartment that 
moves during impact due to the deformation of the floor but remains 
firmly attached to its mounting, would technically fail the retention 
requirement even though it would not pose a projectile hazard.
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    \6\ 65 FR 57985, FMVSS No. 305 Final Rule, September 27, 2000.
---------------------------------------------------------------------------

    The agency elected to respond to Hyundai's interpretation request 
in the June 14, 2010 final rule because the NPRM in this rulemaking had 
already proposed to amend the language of S5.2. Thus, in the final 
rule, the agency responded to that interpretation request stating

    ``The agency agrees that battery modules located inside the 
occupant compartment technically may move a small amount from the 
location from which they are installed during the impact tests. The 
agency also agrees that battery modules located outside the occupant 
compartment that partially move into the occupant compartment 
because of structural deformation of the vehicle structure do not 
impose a projectile hazard provided that they remain attached to the 
mounting structure.\7\ Therefore, the agency concurs that battery 
modules located outside the occupant compartment should be treated 
in the same manner as those located inside the occupant compartment, 
provided that they remain attached to their anchorages.''
---------------------------------------------------------------------------

    \7\ 75 FR 33523.

    Accordingly, the June 14, 2010 final rule revised the regulatory 
---------------------------------------------------------------------------
text to read as follows:

    S5.2 Electric energy storage/conversion system retention. All 
components of the electric energy storage/conversion system must be 
anchored to the vehicle. All component anchorages, including any 
brackets or structures that transfer loads from the component to the 
vehicle structure, shall remain attached to the vehicle structure at 
all attachment locations during and after testing performed pursuant 
to the procedures of S6 of this standard.

    In its petition for reconsideration of the June 14, 2010 final 
rule, the Alliance stated that the final rule's specification that all 
component anchorages, shall remain attached to the vehicle structure at 
all attachment locations is an overly broad requirement that goes 
beyond the intent of assuring that battery system components do not 
become separated from the vehicle. The Alliance stated that this 
language could be interpreted as prohibiting a plastic tie-wrap used to 
position a wiring harness to the vehicle from severing in a crash, a 
requirement that is neither practicable nor necessary.
    The Alliance and the AIAM further stated that some electric energy 
storage/conversion systems, especially those which are located in the 
engine compartment are protected from serious damage resulting from the 
collision by absorbing the energy into deforming or even breaking 
component mountings. The Alliance stated that this was analogous to 
other energy management strategies, such as allowing steering

[[Page 45441]]

columns mountings to deform and break to keep the steering column away 
from the driver of a vehicle during a severe crash. The Alliance stated 
that a battery pack could be mounted to the vehicle at a dozen 
attachment points, and the fact that one of these attachments severs 
during a crash test would be inconsequential to the secure attachment 
of the battery pack to the vehicle, yet violate the language of the 
final rule. The AIAM stated that these system retention provisions may, 
in some respects, be unnecessarily design restrictive and potentially 
contrary to the interests of safety because rather than broadly 
mandating that the battery remain attached to the vehicle, the 
regulatory text places undue emphasis on the condition of individual 
anchorages, brackets and structures.
    Both the AIAM and Honda further argued that the intent of S5.2 was 
to ensure that the battery modules would not become unattached and 
become flying projectiles in a crash or subsequent rollover. Each 
referenced the September 27, 2000 final rule establishing FMVSS No. 305 
\8\ where the agency stated, ``We note that the intent of the proposed 
requirements in S5.2 was to ensure that the battery modules would not 
become unattached and become flying projectiles in a crash or 
subsequent rollover.'' The AIAM stated that this regulatory goal is 
best served by a requirement that broadly focuses on the overall 
condition of the battery module (whether it remains attached to the 
vehicle and has not intruded into the passenger compartment) rather 
than the condition of the individual anchorages.
---------------------------------------------------------------------------

    \8\ 65 FR 57985.
---------------------------------------------------------------------------

    Finally, the AIAM and Honda also stated that there are many smaller 
components that paragraph S5.2 in the June 14, 2010 final rule applies 
to, such as ducts or vents, which may become unattached. They argued 
that the occupant injury risk from such components of the energy 
storage/conversion system is very low, given their small mass and that 
there are no comparable requirements for internal combustion engine 
(ICE) vehicles. The AIAM and Honda stated that in order to exclude low 
mass components of the energy storage/conversion system, such as ducts 
and vents, the retention requirements should apply only to energy 
storage/conversion devices rather than to energy storage/conversion 
systems.
    Each of the petitioners had different strategies for amending the 
requirements for electric energy storage/conversion system retention. 
The Alliance petitioned that in order to avoid unnecessary design 
limitations while achieving protection from both physical damage and 
electrical shock, the following language be adopted for S5.2 of FMVSS 
No. 305:

    ``The following requirements shall be met during and after 
testing performed pursuant to the procedures of S6 of this standard:
    1. Energy storage/conversion system components shall remain 
secured to the vehicle, and
    2. For energy storage/conversion system components located 
outside the passenger compartment, such components shall not enter 
the passenger compartment airspace.''

The Alliance also requested that if the agency does not agree with the 
proposed language, the agency revert to the previous language of S5.2.
    The AIAM petitioned the agency to amend S5.2 to read as follows:

    ``S5.2 Electric energy storage/conversion device(s) retention. 
Electric energy storage/conversion devices must remain attached to 
the vehicle during and after testing performed pursuant to the 
procedures of S6 of this standard.''

    Honda petitioned to amend S5.2 as follows:

    ``S5.2 Electric energy storage/conversion devices(s) retention. 
The electric energy storage/conversion device(s) must remain 
attached to the vehicle by anchorages, brackets, or structures that 
transfer loads from the device(s) to the vehicle structure during 
and after testing performed pursuant to the procedures of S6 of this 
standard.''

    NHTSA's Response: We agree with the comments from the Alliance, 
AIAM, and Honda suggesting that the changes to the retention 
requirement in the June 14, 2010 final rule may be overly broad. We 
acknowledge that increased crash protection for energy storage/
conversion systems can be achieved through the deformation or breaking 
of certain component mounting/anchorages to absorb the crash energy. We 
further acknowledge that the language in the June 14, 2010 final rule 
can be construed to include plastic tie-wraps used to position a wiring 
harness which are not consequential towards the overall condition of 
the energy storage/conversion systems.
    However, we decline to adopt the regulatory text proposed by 
petitioners because we are concerned with ensuring that the final 
standard is clear and objective. Thus, the agency does not believe that 
the proposed language changes from the AIAM and the Alliance are 
appropriate as they require that the electric energy storage/conversion 
devices remain attached without offering any specifics on how the 
agency would distinguish between a device that has ``remained 
attached'' and one that has not. The regulatory text proposed by Honda 
offers more information on what constitutes ``remaining attached'' by 
indicating that the electric energy storage/conversion device must 
remain attached via ``anchorages, brackets, or structures that transfer 
loads from the device(s) to the vehicle.'' However, this approach 
remains unclear as it does not specify how many anchorages, brackets, 
or structures that transfer load must remain attached.
    Thus, today's final rule addresses the considerations of ensuring 
adequate crash protection, creating an objective standard, and enabling 
industry designs that utilize anchorages to redirect crash forces by 
establishing regulatory text which requires that the electric energy 
storage/conversion devices remain attached to the vehicle by at least 
one component anchorage, bracket, or any structure that transfer loads 
from the component to the vehicle structure. Using this regulatory 
text, the agency can afford the manufacturers the maximum amount of 
flexibility to utilize the anchorages as a method for redirecting crash 
forces in their vehicle designs while still ensuring that electric 
energy storage/conversion devices do not become projectiles which can 
potentially injure vehicle occupants. Further, the additional 
regulatory text adds clarity and objectivity to the standard by 
specifying how the agency will distinguish between devices that have 
remained attached versus those that have not. Namely, the additional 
text clarifies that this standard only requires that the electric 
energy storage/conversion devices maintain a connection to the vehicle 
structure at one or more load transferring point after it is tested in 
accordance with the test procedures in S6.
    However, since we are not requiring all component anchorages to 
remain attached to the vehicle at all attachment locations, we believe 
that the June 14, 2010 final rule's conclusion that there is no need to 
treat devices inside the occupant compartment differently from those 
outside the occupant compartment is no longer accurate. While we agree 
with petitioners that the intent of the retention requirement, as 
specified in the 2000 final rule, was to ensure that battery modules 
would not become unattached and become flying projectiles in a crash or 
subsequent rollover, this is not the only purpose of the retention 
requirement. One of the purposes of FMVSS No. 305 is to reduce deaths 
and injuries during and after a crash that occur from the intrusion of 
electric energy storage/conversion devices into the occupant 
compartment.

[[Page 45442]]

In the June 14, 2010 final rule, the S5.2 requirement that all 
component anchorages remain attached to the vehicle structure at all 
attachment locations ensured that the energy storage/conversion system 
would not significantly intrude into the occupant compartment.
    We recognize that, with the new regulatory text for S5.2 in today's 
final rule, there may be an increased potential for electric energy 
storage/conversion devices to partially detach from the vehicle 
structure and intrude into the occupant compartment. To address this, 
we are reintroducing the requirement that any electric energy storage/
conversion device located outside the occupant compartment not intrude 
into the occupant compartment. However, we decline to use the term 
``passenger compartment airspace'' as suggested by the Alliance. A 
similar term ``occupant compartment air space'' was defined by the 
agency in an interpretation letter \9\ of FMVSS No. 302, ``Flammability 
of interior materials.'' Since FMVSS No. 305 addresses safety from 
electrolyte spillage, electric shock, and intrusion of the energy 
storage system, and does not address fire safety, the presence of 
airspace is not relevant and we believe that ``occupant compartment'' 
is the more appropriate term for paragraph S5.2.
---------------------------------------------------------------------------

    \9\ Interpretation to Mazda (North America) Inc.--H. Nayaka: 
February 15, 1983. An ``occupant compartment air space'' is defined 
as ``the space within the occupant compartment that normally 
contains refreshable air.''
---------------------------------------------------------------------------

    We also agree with Honda and the AIAM that the language of the June 
14, 2010 final rule could be interpreted as unintentionally requiring 
low mass components, such as ducts and vents, to remain attached to the 
electric energy storage/conversion systems. As previously discussed, 
today's final rule adds a new definition for ``electric energy storage/
conversion device,'' which includes a high voltage battery or battery 
pack, capacitor modules, fuel cell stacks, and rechargeable energy 
storage devices used for vehicle propulsion, but does not include low 
mass components, such as ducts, vents, and wiring harnesses. As the 
retention requirements of the final rule are amended in today's final 
rule to apply to the electric energy storage/conversion device rather 
than to the system, these changes address the concerns raised by the 
AIAM and Honda by ensuring that the retention requirements do not apply 
to low mass components.
    In conclusion, the regulatory text in paragraph S5.2 has been 
amended to read as follows:
    S5.2 Electric energy storage/conversion device retention. During 
and after each test specified in S6 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.

d. Electrical Safety

1. Clarifying the Requirements in Paragraph S5.3
    Paragraph S5.3 of the June 14, 2010 final rule requires that each 
high voltage source in a vehicle must meet the electrical isolation 
requirements of subparagraph (a) or the voltage level requirements of 
subparagraph (b) after each test. The subsections state:

    (a) The electric isolation between each high voltage source and 
the vehicle chassis electricity-conducting structure must meet one 
of the following:
    (1) Electrical isolation must be greater than or equal to 500 
ohms/volt for all DC high voltage sources without continuous 
monitoring of electrical isolation during vehicle operation and for 
all AC high voltage sources; or
    (2) Electrical isolation must be greater than or equal to 100 
ohms/volt for all DC high voltage sources with continuous monitoring 
of electrical isolation, in accordance with the requirements of 
S5.4, during vehicle operation.
    (b) The voltage of the voltage source must be less than or equal 
to 30 VAC for AC components or 60 VDC for DC components.

    The Alliance stated that it believes that the agency has 
inadvertently written the electrical safety requirements in the final 
rule in a way that would permit compliance with S5.3(a)(2) as the sole 
basis for complying with S5.3 in total. It noted that S5.3 states that 
the vehicle must meet the electrical isolation requirements of 
subparagraph (a) or the voltage requirements of subparagraph (b). It 
further noted that if subparagraph (a) is chosen, the language permits 
compliance to either subparagraph (1) or subparagraph (2), and if 
subparagraph (2) is chosen, there are no isolation requirements 
specified for AC high voltage sources. The Alliance requested 
clarification on whether the agency intended to require 500 ohms/volt 
isolation for AC sources in subparagraph (a) in both the subsidiary 
options of subparagraph (a).
    NHTSA's Response: NHTSA agrees with the Alliance that the 
regulatory text in S5.3(a) could be interpreted to imply that for a 
vehicle with continuous monitoring of electrical isolation, only the DC 
high voltage components need to meet the 100 ohms/volt electrical 
isolation and that there are no requirements for AC high voltage 
components. This was clearly not the intent. We are amending the 
regulatory text of S5.3(a) to indicate that the electrical isolation 
between a given high voltage source and any electrical chassis of the 
vehicle must be greater or equal to one of the following: (1) 500 ohms/
volt for an AC high voltage source, or (2) 500 ohms/volt for a DC high 
voltage source without electrical isolation monitoring, or (3) 100 
ohms/volt for a DC high voltage source with electrical isolation 
monitoring during vehicle operation. In order to further clarify 
paragraph S5.3, we have included references to specific portions of the 
test procedures that apply to the electrical safety requirements. In 
addition, the term ``vehicle chassis electricity conducting structure'' 
in S5.3 has been replaced by the term ``electrical chassis'' to 
maintain consistency with the changes discussed earlier in this 
document. In conclusion, today's final rule amends paragraph S5.3 as 
follows:

    S5.3 Electrical safety. After each test specified in S6 of this 
standard, each high voltage source in a vehicle must meet the 
electrical isolation requirements of subparagraph (a) or the voltage 
level requirements of subparagraph (b).
    (a) The electrical isolation of the high voltage source, 
determined in accordance with the procedure specified in S7.6, must 
be greater or equal to one of the following:
    (1) 500 ohms/volt for an AC high voltage source; or
    (2) 500 ohms/volt for a DC high voltage source without 
electrical isolation monitoring during vehicle operation; or
    (3) 100 ohms/volt for a DC high voltage source with electrical 
isolation monitoring, in accordance with the requirements of S5.4, 
during vehicle operation.
    (b) The voltages V1, V2, and Vb of the high voltage source, 
measured according to the procedure specified in S7.7, must be less 
than or equal to 30 VAC for AC components or 60 VDC for DC 
components.

2. Testing Procedures for S5.3(b) Low Voltage Option
    The Alliance also stated in its petition that S5.3(b) of the final 
rule adopted a low-voltage option for providing electrical isolation, 
while S7.7 specifies the procedure for measuring the voltage. The 
Alliance petitioned that, for purposes of clarity, the language 
currently specified in S7.6.1 regarding voltage measurement locations 
for the electrical isolation option be added to S7.7 for the low-
voltage option.
    NHTSA's Response: The agency agrees with the Alliance that the 
procedure to measure the voltage in S7.6.1 should be added to S7.7 for 
the

[[Page 45443]]

purposes of improving clarity. However, we believe S7.6.1 needs to be 
modified to utilize the new definitions adopted above and to clarify 
the measurement procedure before its contents are added to S7.7. The 
test procedures in paragraph S7.6.1 of the June 14, 2010 final rule 
states:

    For a vehicle that utilizes an automatic disconnect between the 
high voltage source and the traction system that is physically 
contained within the high voltage electric energy storage/
conversion/power generating system, the electrical isolation 
measurement after the test is made from the traction-system side of 
the automatic disconnect to the vehicle chassis electricity-
conducting structure. For a vehicle that utilizes an automatic 
disconnect that is not physically contained within the high voltage 
electric energy storage/conversion/power generating system, the 
electrical isolation measurement after the test is made from both 
the high voltage source side and from the traction-system side of 
the automatic disconnect to the vehicle chassis electricity-
conducting structure.

    As previously discussed, today's final rule has adopted new 
definitions for ``electric power train'' and ``electrical chassis.'' 
Therefore, all instances of the term ``traction-system'' in S7.6.1 are 
replaced by the term ``electric power train'' and all instances of the 
term ``vehicle chassis electricity-conducting structure,'' are replaced 
by the term ``electrical chassis.'' This final rule also amends the 
definition for ``high voltage source'' to include electric components 
contained in the electric power train and those connected to it. For 
high voltage sources contained within the electric power train, the 
regulatory text of S7.6.1 and S7.7 have been amended to indicate that 
the electrical isolation measurement is made from the side of the 
automatic disconnect that is connected to ``the rest of the electric 
powertrain.'' In addition, the regulatory text of the June 14, 2010 
final rule S7.6.1 indicates that the ``automatic disconnect'' only 
applies to high voltage sources within the vehicle's energy storage/
conversion/power generating system. We believe that this regulatory 
text may be misconstrued, since the intent of the agency was that the 
specifications for the electrical isolation measurement locations with 
respect to the automatic disconnects in S7.6.1 apply to each high 
voltage source with automatic disconnects. Therefore, the regulatory 
text of S7.6.1 in today's final rule is modified as follows and 
incorporated into S7.7 as requested by the Alliance:

    For a high voltage source that has an automatic disconnect that 
is physically contained within itself, the electrical isolation 
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 electrical isolation 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.

    However, to ensure consistency and clarity of terminology, today's 
final rule also revises the first sentence in S7.6.1 to indicate that 
the electric energy storage/conversion system (rather than the high 
voltage source) is connected to the vehicle's propulsion system to 
enable the propulsion system to be energized when the vehicle ignition 
is in the ``on'' position. A similar clarification is made in S7.2 by 
replacing ``high voltage system'' (which is not defined in the 
regulatory text) with ``electric energy storage/conversion system'' and 
``propulsion motors'' with ``propulsion system.''

e. Electrical Isolation Monitoring

    While the NPRM did not propose a requirement for electrical 
isolation monitoring, we acknowledged in the NPRM that the petitioner 
for rulemaking requested that FMVSS No. 305 allow for DC high voltage 
sources to meet a 100 ohms/volt electrical isolation requirement when 
coupled with electrical isolation monitoring. In the final rule, based 
on our analysis of comments on the NPRM, we required that each DC high 
voltage source meet 500 ohms/volt electrical isolation for vehicles 
without continuous electrical isolation monitoring but allowed DC high 
voltage sources to meet 100 ohms/volt electrical isolation if the 
vehicle had continuous monitoring of electrical isolation during 
vehicle operation. We required that the system must monitor its own 
readiness and provide a warning display that must be clearly visible 
from the driver's designated seating position for loss of isolation 
when tested according to the test procedure in S8.
    The agency stated its belief that electrical isolation monitoring 
is especially needed for electrical components whose electrical 
isolation may degrade over time such as fuel cell stacks in fuel cell 
vehicles where the coolant may increase in conductivity during vehicle 
service and thereby result in a reduction of electrical isolation. 
Since it is anticipated that the 100 ohms/volt electrical isolation 
requirement for DC high voltage components would likely be exercised 
for the fuel cell stacks and other such electrical components whose 
isolation may degrade over time, we included the need for isolation 
monitoring of these components in the final rule.
    In its petitions for reconsideration, Honda stated that the level 
of protection against electric shock should be judged by the absolute 
value of electrical isolation resistance. Honda argued that whether or 
not the vehicle is equipped with an isolation monitor has no relation 
to the possibility of electric shock resulting from touching the high 
voltage bus after a crash. Honda proposed removing entire sections of 
S5.4 and S8 related to isolation monitoring systems. Honda noted that 
the 2009 SAE J2578 \10\ and the 2009 ISO 6469-3 \11\ draft standards do 
not require electrical isolation monitoring for electrical components 
with 100 ohms/volt electrical isolation and requested that the 
electrical isolation monitoring requirements be removed to resolve the 
differences between the FMVSS No. 305 and the SAE/ISO standards.
---------------------------------------------------------------------------

    \10\ SAE J2578--Recommended practice for general fuel cell 
vehicle safety, SAE J2578-2009-01, Society of Automotive Engineers, 
http://standards.sae.org/j2578_200901/.
    \11\ ISO 6469-3--Electrically propelled road vehicles--Safety 
specification--Part 3: Protection of persons against electric shock, 
2009, http://www.iso.org/iso/catalogue_detail?csnumber=45479.
---------------------------------------------------------------------------

    Honda requested that if NHTSA decides not to remove the electrical 
isolation monitoring requirement, it instead permit periodic electrical 
isolation monitoring systems such as those that do not monitor the 
electrical isolation during start-up of vehicle/system (until main 
contactor is connected). Honda stated that the 2010 draft of ISO 6469-3 
and the 2006 draft of ISO 23273-3 permit both continuous and periodic 
electrical isolation measurements during vehicle operation and that 
``periodic'' systems would also detect a failure in isolation and 
appropriately warn the driver. Therefore, Honda proposed FMVSS No. 305 
include the words ``or periodic'' after the word, ``continuous'' in 
S5.3, S5.4 and S8.
    Further, Honda stated that the electrical isolation monitoring 
system only monitors the entire system during normal vehicle operation 
and is not capable of independently monitoring each high voltage 
source. Therefore, Honda requested that the agency clarify that the 
electrical isolation monitoring system will not be required to 
independently monitor each high voltage source by deleting the words 
``For each continuously monitored DC

[[Page 45444]]

high voltage source,'' from the regulatory text in S5.4.
    Finally, Honda stated that the test procedure to determine the 
operation of isolation monitoring systems does not allow flexibility in 
selecting the resistor that is inserted between the positive terminal 
of the high voltage source and the vehicle chassis electric conducting 
structure. Honda noted that, as prescribed, S8(4) requires inserting a 
resistor with resistance equal to the calculated result 1/(1/(95 times 
the working voltage of the high voltage source)--1/Ri) and does not 
allow any flexibility. Honda petitioned to allow any higher resistor to 
be used in the test procedure to determine if the isolation monitoring 
system is operating correctly arguing that the stringency of the test 
would not be compromised since higher resistance would provide a worse 
case condition.
    NHTSA's Response--While we agree with Honda that isolation 
monitoring is intended to identify the possibility of deteriorated 
isolation that occurs over time during the normal service life of the 
vehicle and that an isolation monitor is not intended to guard against 
the possibility of electric shock resulting from touching a high 
voltage source after a crash, we do not agree that the requirement for 
electrical isolation monitoring should be deleted from the standard. 
The requirement that DC high voltage sources be monitored during 
vehicle operation with an isolation monitoring system that displays a 
warning for loss of electrical isolation is similar to the air bag 
readiness indicator required by FMVSS No. 208, ``Occupant crash 
protection.'' Neither the electrical isolation warning display nor the 
air bag readiness indicator provides protection during or after a 
crash. However, these indicators serve to provide the driver 
information that the related system may not be in proper working 
condition. Electrical isolation monitoring addresses a relevant safety 
concern because electric vehicles that use the 100 ohms/volt electrical 
isolation option to comply with the electrical safety requirements may 
likely be powered by fuel cells which have coolant that can deteriorate 
the electrical isolation over time. The agency made the decision to 
require electrical isolation monitoring based on careful analysis of 
the electrical safety concerns associated with providing adequate 
electrical shock protection both during vehicle operation and following 
a crash.
    We also note that the electrical isolation and the electrical 
isolation monitoring requirements in the June 14, 2010 final rule were 
consistent with the joint Alliance/AIAM comments to the NPRM and SAE 
J1766. The standards referred to by Honda in its petition (SAE J2578 
and ISO 6469-3) are draft documents that may be subject to change. For 
example, the 2009 draft of ISO 6469-3 does not require electrical 
isolation monitoring while the 2010 version makes provisions for 
continuous and periodic electrical isolation monitoring. As the 
aforementioned voluntary standards are still in flux regarding 
requiring electrical isolation monitoring, and as the agency believes 
that electrical isolation monitoring addresses an important safety 
concern by warning the driver of a possible degradation in electrical 
isolation, we are denying Honda's petition to remove the electrical 
isolation monitoring requirements from S5.4 and S8.
    However, we agree with Honda's petition that the term 
``continuous'' in the electrical isolation monitoring system 
requirement should be clarified. Since the standard provides a test 
procedure and performance criteria for assessing the operation of the 
electrical isolation monitoring system, we believe there is no need to 
specify the type of monitoring system. The only requirement contained 
in today's final rule is that the monitoring systems meet the 
performance criteria in S5.4 when tested according to the procedure in 
S8. Therefore, rather than adding the additional term ``or periodic,'' 
as suggested by Honda, we are deleting the specification for the 
monitoring system to be ``continuous'' in S5.3, S5.4, and S8 to address 
its concern. We are also modifying the regulatory text of S5.4 slightly 
to improve clarity.
    We agree with Honda that electrical isolation monitoring systems 
may only monitor the whole vehicle system. However, the regulatory 
requirements in S5.4 only apply to those DC high voltage sources that 
manufacturers have chosen to certify to the 100 ohms/volt electrical 
isolation requirement and do not comply with the 500 ohms/volt 
electrical isolation requirement. Therefore, the test procedure in S8 
evaluates the performance of the monitoring system for each DC high 
voltage source that is certified to 100 ohms/volt electrical isolation. 
The procedures in S8 are intended to test for the condition when 
electrical isolation of each DC high voltage source (certified to the 
100 ohms/volt requirement) falls below 100 ohms/volt. Therefore, we do 
not grant Honda's request to remove the phrase ``For each continuously 
monitored DC high voltage source'' from the regulatory text in S5.4.
    Finally, Honda also petitioned for flexibility in the use of any 
higher resistor in the test procedure to determine if the isolation 
monitoring system is operating correctly. It argued that allowing a 
higher resistance would not compromise the stringency of the 
requirements since it would provide for a worse case condition. In the 
June 14, 2010 final rule, the resistance of the external resistor 
applied in the test procedure detailed in S8 is calculated such that 
the combined electrical isolation resistance of the high voltage source 
and the external resistor results in electrical isolation of 95 ohms/
volt which is 95 percent of the required electrical isolation. The 
electrical isolation monitor is required to display a warning when the 
electrical isolation falls to 95 ohms/volt. If the resistance of the 
external resistor applied in the test is greater than that specified in 
S8, as requested by Honda, then we agree that the combined electrical 
isolation for which the monitoring system will need to display a 
warning may be greater than 100 ohms/volt, thereby making the 
requirement more stringent.
    The final rule requires 100 ohms/volt electrical isolation for 
monitored DC high voltage sources. For compliance purposes, we are 
assessing the operation of the monitoring system when the electrical 
isolation falls just below the required value. The final rule does not 
preclude manufacturers from having the isolation monitor warning 
display come on at a higher value than the minimum electrical isolation 
of 100 ohms/volt. Therefore, we do not believe it is necessary to grant 
Honda's request to change S8(4) to include an external resistor of 
higher resistance than that specified by the calculation.
    However, we do see merit in including some flexibility in the 
resistance of the external resistor selected to evaluate the electrical 
isolation monitoring system such that it is easy for the testing 
personnel to select an off-the-shelf resistor instead of having to 
build a resistor to meet the exact computed resistance of the external 
resistor. Therefore, we are specifying that the resistance of the 
external resistor be such that the combined electrical isolation is 
greater or equal to 95 ohms/volt but less than 100 ohms/volt. This will 
allow the agency to test the operation of the monitoring system when 
the electrical isolation falls just below the required 100 ohms/volt, 
and will provide manufacturers additional flexibility in selecting 
resistors for testing.

f. Electric Energy Storage Device State-of-Charge

    In the June 14, 2010 final rule, we required that prior to the 
crash test, the electric energy storage device be at the

[[Page 45445]]

maximum state-of-charge recommended by the manufacturer, as stated in 
the vehicle owner's manual or on a label that is permanently affixed to 
the vehicle; or if the manufacturer has made no recommendation 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; or 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. These state-of-charge provisions in the June 
14, 2010 final rule were substantively identical to the original FMVSS 
No. 305 that existed before the NPRM in this rulemaking.
    In its petition asking the agency to reconsider these provisions, 
the Alliance requested that FMVSS No. 305 be amended to allow testing 
at ``any state-of-charge which allows the normal operation of the power 
train as recommended by the manufacturer.'' In support of this request, 
the Alliance stated that the United Nations Economic Commission for 
Europe (UNECE) draft regulations (ECE R.94 and 95) \12\ already propose 
to permit testing of electric vehicles at any state-of-charge. The 
Alliance stated that this proposed change would (1) allow for systems 
with external charging capability to be tested at lower state-of-charge 
(similar to hybrid electric vehicles), (2) result in reduced facility/
test personnel risk (similar to the current use of stoddard in fuel 
systems), and (3) further provide an opportunity for harmonization with 
UNECE regulations. Thus, the Alliance argued that in the interest of 
safety in the testing environment and harmonization, the UNECE 
allowance on state-of-charge should be adopted.
---------------------------------------------------------------------------

    \12\ ECE R.94--Uniform Provisions Concerning the Approval of 
Vehicles with Regard to the Protection of the Occupants in the Event 
of a Frontal Collision, draft modifications of September 2010. ECE 
R.95--Uniform Provisions Concerning the Approval of Vehicles with 
Regard to the Protection of the Occupants in the Event of a Lateral 
Collision, draft modifications of September 2010.
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    Ford also offered comments regarding the state-of-charge and the 
FMVSS No. 305 test conditions. Ford stated that state-of-charge does 
not affect the energy storage/conversion system mass, electrolyte 
volume or containment capability and does not affect electrical 
isolation. Ford presented theoretical examples of systems suffering 
loss of electrical isolation during the crash test prescribed in the 
standard. Using the electrical isolation test procedure outlined in the 
standard, Ford demonstrated that the loss in electrical isolation was 
detected when the system was energized at 95 percent and 5 percent of 
the maximum state-of-charge. Ford agreed with the Alliance that the 
lower state-of-charge would reduce potential risk to test personnel 
similar to the use of substitute liquids and gases in other FMVSSs.
    In addition, Honda's petition stated that the state-of-charge 
testing requirements should be amended to address new technologies such 
as plug in hybrid electric vehicles (PHEVs) which will become common in 
the near future. Honda noted that the regulatory text indicates that if 
the manufacturer of vehicles (such as PHEVs) recommends a specific 
maximum state-of-charge, the test would be conducted at the specified 
maximum state-of-charge. However, if the manufacturer has no 
recommendation, the test would be conducted at a state-of-charge of not 
less than 95 percent of the maximum capacity of the electric energy 
storage device.
    Honda argued that the state-of-charge for an electric energy 
storage device can vary due to environmental conditions such as 
temperature or service life and that it will not be recommending a 
specific state-of-charge in the owner's manual or on the label affixed 
to the vehicle because the electric energy storage device is charged 
appropriately by an off-board and/or on-board charger recommended by 
the manufacturer. Thus, Honda petitioned to have the regulatory text of 
S7.1 changed from ``recommended by the manufacturer, as stated in the 
vehicle owner's manual or on a label that is permanently affixed to the 
vehicle'' to ``in accordance with the vehicle manufacturer's 
recommended charging procedures.'' For those manufacturers that make no 
recommendation, Honda further petitioned to have the regulatory text of 
S7.1(b) changed from ``made no recommendation in the owner's manual or 
on a label permanently affixed to the vehicle'' to ``made no 
recommendation for charging procedures.''
    NHTSA's Response: NHTSA does not agree with the Alliance and Ford 
that the electric energy storage device should be at any state-of-
charge that allows for the normal operation of the power train as 
recommended by the manufacturer. Specifying the state-of-charge 
provides a uniform way of testing and ensures all electric powered 
motor vehicles are tested in a similar manner.
    We agree with Ford that the electrical isolation resistance 
measurement remains unchanged for different operating voltages and that 
loss in electrical isolation can be detected by the method outlined in 
the standard for different states of charge. However, we are concerned 
that certain electric components, such as capacitor networks within the 
electric power train may not be tested to their design limits when 
tested at a lower state-of-charge. When the vehicle crash test is 
conducted at the maximum state-of-charge, there is potential for some 
of the capacitor voltages to reach their design limits which may result 
in an electric short and hence cause a loss in electrical isolation. 
This potential safety hazard may not occur when the vehicle is tested 
at a lower state-of-charge which results in a lower energy test 
condition. We also do not agree with petitioners that testing at lower 
state-of-charge to evaluate electrical safety is similar to fuel system 
integrity testing with stoddard fluid in gasoline powered vehicles and 
nitrogen in compressed natural gas vehicles. While use of stoddard 
fluids and nitrogen do not change the performance of the fuel 
containers during and after the test, using lower state-of-charge may 
not evaluate certain electrical components at their design limits.
    We further note that the December 2010 draft of SAE J2929--
``Electric and Hybrid Vehicle Propulsion Battery System Safety Standard 
for Lithium-Based Rechargeable Cells,'' requires the battery state-of-
charge to be at the maximum possible during normal vehicle operation 
before the battery system is tested for mechanical shock hazard in a 
vehicle pursuant to FMVSS No. 305. While the draft SAE J2929 test 
applies to different safety concerns, it does involve the same crash 
tests as this standard and utilizes similar state-of-charge 
requirements. Therefore, the agency's position on the state-of-charge 
of the energy storage/conversion system prior to the crash test is 
consistent with the future voluntary industry standard for battery 
systems. We are therefore denying the petition from the Alliance and 
Ford to conduct the crash test at any state-of-charge which allows the 
normal operation of the power train as recommended by the manufacturer.
    However, we agree with Honda that the maximum state-of-charge may 
vary based on environmental conditions such as the age of the battery, 
temperature and service life for today's battery technologies. Thus, 
having the label specify the maximum state-of-charge in the owner's 
manual or a label permanently affixed to the vehicle may not provide 
consumers the information they need to recharge their vehicle 
throughout the vehicle's life. However, manufacturers will likely 
provide information to consumers on the proper charging procedures to 
achieve

[[Page 45446]]

maximum range, as suggested by Honda. Therefore, we are modifying the 
regulatory text to indicate that the maximum state-of-charge in 
accordance with the vehicle manufacturer's recommended charging 
procedure, as stated in the vehicle owner's manual or on a label that 
is permanently affixed to the vehicle, will be used. In the case where 
no such recommendation is provided in the owner's manual or on a label 
permanently affixed to the vehicle, the test will be conducted with the 
electric energy storage/conversion device charged to 95 percent of its 
rated capacity.

 g. Physical Barrier Compliance Option for Electrical Safety

    The June 14, 2010 final rule did not include a physical barrier 
compliance option for electrical safety since it was beyond the scope 
of the rulemaking. In addition, the agency stated in the final rule 
that it was uncertain whether indirect contact failure modes would be 
sufficiently accounted for by the protective barrier compliance option 
and noted that it had initiated a research program to better understand 
the issues.
    In its petition for reconsideration, the Alliance disagreed with 
the agency's concern that the physical barrier option may not 
appropriately address electrical shock from indirect contact. The 
Alliance stated its belief that the test procedure for the protective 
barrier compliance option is equally valid for assessing both direct 
and indirect contact. It stated that the basic premise of the 
protective barrier compliance option is that if a person cannot contact 
high voltage sources, then there is little chance of injury from such 
sources.
    The Alliance further stated that there is worldwide recognition and 
acceptance of the barrier option as a means for providing electrical 
safety, and updating FMVSS No. 305, as requested, would be a key 
enabler facilitating the introduction of all forms of electric-powered 
vehicles into the U.S. mainstream vehicle fleet. It argued that such 
vehicle technologies are vital to achieving the current 
Administration's energy and emissions goals. The Alliance further 
stated that given the urgent need for the barrier option and the fact 
that the barrier option in the draft GTR language (the ELSA document) 
is fully accepted by the international community, it is not necessary 
to delay a rulemaking proposal. Accordingly, the Alliance requested 
that NHTSA initiate a new rulemaking to incorporate the barrier option 
into FMVSS No. 305, and to complete this rulemaking with an urgency 
that is consistent with the national priorities to improve energy 
independence and reduced emissions.
    NHTSA's Response: Our position on the requested physical barrier 
option has not substantively changed since the June 14, 2010 final 
rule. As noted in the June 14, 2010 final rule, NHTSA is doing research 
to evaluate the suitability of including the protective barrier option 
in FMVSS No. 305. NHTSA is aware that other countries have adopted a 
similar option in their regulations for electrical safety, but that 
does not eliminate the need for the agency to obtain the necessary 
supporting research to fully understand the consequences of adding this 
option as a means for providing electrical safety in FMVSS No. 305. 
Prior to changing any safety standard, NHTSA must first ensure that the 
proposed requirement provides an adequate level of safety and does not 
create an inadvertent safety risk to the motoring public, or first 
responders responding to the scene of a crash. Upon completion of the 
agency's research, NHTSA will make a decision whether to include 
physical barriers as an option for providing electrical safety in FMVSS 
No. 305. If the agency decides that a proposal for the protective 
barrier compliance option has merit, it will propose performance 
requirements, as well as a test procedure, at that time.

h. Use of Alternative Gas for Testing Hydrogen Fuel Cell Vehicles

    The June 14, 2010 final rule also did not include a provision for 
testing hydrogen fuel cell vehicles using an inert gas, such as helium. 
When testing with an inert gas, the fuel cell stacks are not energized 
and consequently will not generate any electrical energy from which to 
measure electrical output. The final rule stated that the agency was 
researching potential crash test procedures for testing fuel cell 
vehicles, but would not address this issue as part of the June 14, 2010 
final rule.
    Petitions for reconsideration from the AIAM and Honda requested the 
agency to expedite this research so that a decision can be made in the 
near future for testing hydrogen fuel cell vehicles with helium-filled 
fuel containers. The organizations noted that fuel cell vehicles will 
be required to comply with FMVSS No. 305 by September 1, 2011. They 
argued that testing for those vehicles will then have to be conducted 
using hydrogen gas in accordance with the current regulation, if no 
changes are made. The AIAM and Honda further stated that other FMVSS 
crash test procedures (i.e. FMVSS Nos. 208, ``Occupant crash 
protection,'' 214, ``Side impact crash protection,'' 301, ``Fuel system 
integrity,'' and 303, ``Fuel system integrity of compressed natural gas 
vehicles'') require filling the fuel tank with alternative fuel to 
ensure safety during and after the crash test and the use of gasoline, 
diesel, and compressed natural gas in such tests is prohibited. The 
organizations requested that the test procedure for FMVSS No. 305 be 
aligned with the procedures of other existing crash-related 
regulations. Both organizations further reiterated their original 
comments to the NPRM that current Japanese regulations require the use 
of helium gas in crash tests, and prohibit the use of hydrogen.
    NHTSA's Response--As noted in the June 14, 2010 final rule, the 
agency has ongoing research in developing a test procedure for 
evaluating the electrical safety of fuel cell vehicles with an inert 
gas and inactive fuel cells and the agency's position has not 
substantively changed since then. When an inert gas is used instead of 
hydrogen in fuel cell vehicles, some of the electrical components of 
the electric power train may be rendered inactive. Currently, the 
agency has not developed a test procedure to test the electrical safety 
of all high voltage sources accurately when an inert gas is used during 
testing of fuel cell vehicles. We note that while the Japanese 
regulation and the ELSA document permit the use of helium gas in crash 
tests of hydrogen powered vehicles, both the Japanese regulation and 
the ELSA document do not specify a test procedure to evaluate the 
electrical safety of such vehicles when an inert gas is used in place 
of hydrogen.
    Therefore, the agency believes further work is needed to resolve 
the identified issues in testing hydrogen fuel cell vehicles. While 
there are currently no explicit provisions for using an alternative gas 
in lieu of hydrogen, comparable to the fuel system integrity standards 
for gasoline or compressed natural gas powered vehicles, the test 
procedures in an FMVSS are those that the agency will use to determine 
compliance to the particular standard. Manufacturers are not prohibited 
from using other test procedures for compliance certification and may 
elect to conduct crash tests of hydrogen fuel cell vehicles with a less 
volatile gas such as helium.

i. Low-Energy Compliance Option for Electrical Safety

    Although the NPRM sought comment on whether or not the requested 
low-energy compliance option for electrical safety should be included, 
it did not include this option in the proposed rule. After carefully 
considering the

[[Page 45447]]

comments received, the agency did not include the low-energy compliance 
option in the June 14, 2010 final rule as we remained unconvinced that 
the option was necessary and that it would adequately address the 
safety concerns of FMVSS No. 305. In its petition for reconsideration, 
the Alliance stated its continued belief that the low-energy option has 
merit and should be included in FMVSS No. 305. However, the Alliance 
also recognized that more research may be required in order to fully 
understand the safety implications of this option. Given the available 
information on the low-energy compliance option for electrical safety 
has not significantly changed, NHTSA's position on the low-energy 
compliance option remains as expressed in the June 14, 2010 final rule.

V. Rulemaking Analyses and Notices

a. Executive Order 12866, Executive Order 13563, and DOT Regulatory 
Policies and Procedures

    NHTSA has considered the impact of this rulemaking action under 
Executive Order 12866, Executive Order 13563, and the Department of 
Transportation's regulatory policies and procedures. This rulemaking 
document was not reviewed by the Office of Management and Budget under 
E.O. 12866, ``Regulatory Planning and Review.'' It is not considered to 
be significant under E.O. 12866 or the Department's Regulatory Policies 
and Procedures (44 FR 11034; February 26, 1979). NHTSA has determined 
that the effects of this final rule are minor and that a regulatory 
evaluation is not needed to support the subject rulemaking. Today's 
final rule only makes slight changes to the regulatory text of the June 
14, 2010 final rule to add clarification and does not impose 
significant costs beyond those already required by the June 14, 2010 
final rule.

b. Regulatory Flexibility Act

    Pursuant to the Regulatory Flexibility Act (5 U.S.C. 601 et seq., 
as amended by the Small Business Regulatory Enforcement Fairness Act 
(SBREFA) of 1996), whenever an agency is required to publish a notice 
of proposed rulemaking or final rule, it must prepare and make 
available for public comment a regulatory flexibility analysis that 
describes the effect of the rule on small entities (i.e., small 
businesses, small organizations, and small governmental jurisdictions). 
No regulatory flexibility analysis is required if the head of an agency 
certifies the rule will not have a significant economic impact on a 
substantial number of small entities. SBREFA amended the Regulatory 
Flexibility Act to require Federal agencies to provide a statement of 
the factual basis for certifying that a rule will not have a 
significant economic impact on a substantial number of small entities.
    NHTSA has considered the effects of this final rule under the 
Regulatory Flexibility Act. I certify that this final rule does not 
have a significant economic impact on a substantial number of small 
entities. Any small manufacturers that might be affected by this final 
rule are already subject to the requirements of FMVSS No. 305. Further, 
the agency believes the testing associated with the requirements added 
by this final rule are not substantial and to some extent are already 
being voluntarily borne by the manufacturers pursuant to SAE J1766, SAE 
J2578, ECE regulations, and other voluntary industry standards. 
Therefore, the impacts on any small businesses affected by this 
rulemaking would not be substantial.

c. Executive Order 13132 (Federalism)

    NHTSA has examined today's final 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 final 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 final 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.'' Today's 
final rule does not impose substantial additional requirements. 
Instead, it clarifies the existing requirements from the June 14, 2010 
final rule.
    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 \13\ addressing 
the same aspect of performance, not today's rulemaking.

    \13\ The issue of potential preemption of state tort law is 
addressed in the immediately following paragraph discussing implied 
preemption.
---------------------------------------------------------------------------

    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. However, the Supreme 
Court has recognized the possibility, in some instances, of implied 
preemption of State common law tort causes of action by virtue of 
NHTSA's rules--even if not expressly preempted.
    This second way that NHTSA rules can preempt is dependent upon the 
existence of an actual conflict between an FMVSS and the higher 
standard that would effectively be imposed on motor vehicle 
manufacturers if someone obtained a State common law tort judgment 
against the manufacturer--notwithstanding the manufacturer's compliance 
with the NHTSA standard. 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 today's rule 
and finds that this rule merely clarifies the requirements and 
definitions contained in the June 14, 2010 final rule. As such, NHTSA 
does not intend that this rule preempt state tort law that would 
effectively impose a higher standard on

[[Page 45448]]

motor vehicle manufacturers than that established by today's rule. 
Additionally, in the June 14, 2010 final rule, the agency did not 
assert preemption. Establishment of a higher standard by means of State 
tort law would not conflict with the exemption announced here. Without 
any conflict, there could not be any implied preemption of a State 
common law tort cause of action.

d. National Environmental Policy Act

    NHTSA has analyzed this rulemaking action for the purposes of the 
National Environmental Policy Act. The agency has determined that 
implementation of this action will not have any significant impact on 
the quality of the human environment.

e. Executive Order 12988 (Civil Justice Reform)

    When promulgating a regulation, agencies are required under 
Executive Order 12988 to make every reasonable effort to ensure that 
the regulation, as appropriate: (1) Specifies in clear language the 
preemptive effect; (2) specifies in clear language the effect on 
existing Federal law or regulation, including all provisions repealed, 
circumscribed, displaced, impaired, or modified; (3) provides a clear 
legal standard for affected conduct rather than a general standard, 
while promoting simplification and burden reduction; (4) specifies in 
clear language the retroactive effect; (5) specifies whether 
administrative proceedings are to be required before parties may file 
suit in court; (6) explicitly or implicitly defines key terms; and (7) 
addresses other important issues affecting clarity and general 
draftsmanship of regulations.
    Pursuant to this Order, NHTSA notes as follows. The preemptive 
effect of today's final rule is discussed above. NHTSA notes further 
that there is no requirement that individuals submit a petition for 
reconsideration or pursue other administrative proceeding before they 
may file suit in court.

f. 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.

g. Paperwork Reduction Act

    Under the Paperwork Reduction Act of 1995 (PRA), 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. There are no 
information collection requirements associated with this final rule.

h. National Technology Transfer and Advancement Act

    Under the National Technology Transfer and Advancement Act of 1995 
(NTTAA) (Pub. L. 104-113), ``all Federal agencies and departments shall 
use technical standards that are developed or adopted by voluntary 
consensus standards bodies, using such technical standards as a means 
to carry out policy objectives or activities determined by the agencies 
and departments.'' 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, 
explanations when we decide not to use available and applicable 
voluntary consensus standards. FMVSS No. 305 has historically drawn 
largely from SAE J1766. Prior to this update, FMVSS No. 305 was based 
on the April 2005 version of SAE J1766. However, today's final rule has 
made certain amendments to the standard to reflect the development of 
new voluntary consensus standards that have superseded SAE J1766. Thus, 
today's final rule makes revisions to the June 14, 2010 final rule that 
updated FMVSS No. 305.

i. Unfunded Mandates Reform Act

    The Unfunded Mandates Reform Act of 1995 requires 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). Today's final rule, 
which clarifies the June 14, 2010 final rule, will not result in 
expenditures by State, local or Tribal governments, in the aggregate, 
or by the private sector in excess of $100 million annually.

j. 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 notify the 
agency in writing.

k. Regulation Identifier Number (RIN)

    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.

VI. Regulatory Text

List of Subjects in 49 CFR part 571

    Imports, Motor vehicles, Motor vehicle safety.

    In consideration of the foregoing, NHTSA amends 49 CFR part 571 as 
follows:

PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS

0
1. 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 1.50.

0
2. Amend Sec.  571.305 by revising S1, S2, S3, S4, S5.2, S5.3, S5.4, 
S7.1, S7.2, S7.6.1, S7.6.4, S7.6.5, S7.6.6, S7.6.7, S7.7, and S8 and 
Figures 1 through 5 as follows:

Sec.  571.305  Standard No. 305; Electric-powered vehicles: Electrolyte 
spillage and electrical shock protection.

    S1. Scope. This standard specifies requirements for limitation of 
electrolyte spillage, retention of electric energy storage/conversion 
devices, and protection from harmful electric shock during and after a 
crash.
    S2. Purpose. The purpose of this standard is to reduce deaths and 
injuries

[[Page 45449]]

during and after a crash that occurs because of electrolyte spillage 
from electric energy storage devices, intrusion of electric energy 
storage/conversion devices into the occupant compartment, and 
electrical shock.
    S3. Application. This standard applies to passenger cars, and to 
multipurpose passenger vehicles, trucks and buses with a GVWR of 4,536 
kg or less, that use electrical propulsion components with working 
voltages more 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.
    S4. Definitions.
    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.
    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.
    High voltage source means any electric component contained in the 
electric power train or conductively connected to the electric power 
train that has a working voltage greater than 30 VAC or 60 VDC.
    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, electronic 
controllers, and associated wire harnesses and connectors, and coupling 
systems for charging rechargeable energy storage systems.
* * * * *
    S5.2 Electric energy storage/conversion device retention. During 
and after each test specified in S6 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.
    S5.3 Electrical safety. After each test specified in S6 of this 
standard, each high voltage source in a vehicle must meet the 
electrical isolation requirements of subparagraph (a) or the voltage 
level requirements of subparagraph (b).
    (a) The electrical isolation of the high voltage source, determined 
in accordance with the procedure specified in S7.6, must be greater 
than or equal to one of the following:
    (1) 500 ohms/volt for an AC high voltage source; or
    (2) 500 ohms/volt for a DC high voltage source without electrical 
isolation monitoring during vehicle operation; or
    (3) 100 ohms/volt for a DC high voltage source with electrical 
isolation monitoring, in accordance with the requirements of S5.4, 
during vehicle operation.
    (b) The voltages V1, V2, and Vb of the high voltage source, 
measured according to the procedure specified in S7.7, must be less 
than or equal to 30 VAC for AC components or 60 VDC for DC components.
    S5.4 Electrical isolation monitoring. Each DC high voltage source 
with electrical isolation monitoring during vehicle operation pursuant 
to S5.3(a)(2) shall be monitored by an electrical isolation monitoring 
system that displays a warning for loss of isolation when tested 
according to S8. The system must monitor its own readiness and the 
warning display must be visible to the driver seated in the driver's 
designated seating position.
* * * * *
    S7.1 Electric energy storage device state-of-charge. The electric 
energy storage device shall be at the state-of-charge specified in 
either subparagraph (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; 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.
    S7.2 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.
* * * * *
    S7.6.1 Prior to any barrier impact test, the energy storage/
conversion system is connected to the vehicle's propulsion system, and 
the vehicle ignition is in the ``on'' (propulsion system energized) 
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. For a high 
voltage source that has an automatic disconnect that is physically 
contained within itself, the electrical isolation 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 electrical isolation 
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.
* * * * *

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    S7.6.4 The voltage(s) is/are measured as shown in Figure 2, and the 
voltage(s) (V1) between the negative side of the high voltage source 
and the electrical chassis.
    S7.6.5 The voltage(s) is/are measured as shown in Figure 3, and the 
voltage(s) (V2) between the positive side of the high voltage source 
and the electrical chassis.
    S7.6.6 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 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).
    S7.6.7 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 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).
    S7.7 Voltage measurement. For the purpose of determining the 
voltage level of the high voltage source specified in S5.3(b), voltage 
is measured as shown in Figure 1. Voltage Vb is measured across the two 
terminals of the voltage source. Voltages V1 and V2 are measured 
between the source and the electrical chassis. For a high voltage 
source that has an automatic disconnect that is physically contained 
within itself, the electrical isolation 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 electrical isolation 
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.
    S8. Test procedure for on-board electrical isolation monitoring 
system. Prior to any impact test, the requirements of S5.4 for the on-
board electrical isolation monitoring system shall be tested using the 
following procedure.
    (1) The electric energy storage device is at the state-of-charge 
specified in S7.1.
    (2) The switch or device that provides power from the high voltage 
system to the propulsion motor(s) is in the activated position or the 
ready-to-drive position.
    (3) Determine the isolation resistance, Ri, of the high voltage 
source with the electrical isolation monitoring system using the 
procedure outlined in S7.6.2 through S7.6.7.
    (4) 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.
    (5) The electrical isolation monitoring system indicator shall 
display a warning visible to the driver seated in the driver's 
designated seating position.
BILLING CODE 4910-59-P
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    Issued on: July 25, 2011.
David L. Strickland,
Administrator.
[FR Doc. 2011-19216 Filed 7-28-11; 8:45 am]
BILLING CODE 4910-59-C