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GB 38031-2020: Electric vehicles traction battery safety requirements
GB 38031-2020
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 43.080
T 47
Replacing GB/T 31485-2015, GB/T 31467.3-2015
Electric Vehicles Traction Battery Safety requirements
ISSUED ON: MAY 12, 2020
IMPLEMENTED ON: JANUARY 1, 2021
Issued by: State Administration for Market Regulation;
Standardization Administration of the People’s Republic of
China.
Table of Contents
Foreword ... 3 
Introduction ... 6 
1 Scope ... 7 
2 Normative References ... 7 
3 Terms and Definitions ... 7 
4 Abbreviations and Symbols ... 10 
4.1 Abbreviations ... 10 
4.2 Symbols ... 10 
5 Safety Requirements ... 10 
5.1 Safety Requirements of Secondary Cell ... 10 
5.2 Safety Requirements of Battery Pack or System ... 11 
6 Test Conditions ... 12 
6.1 General Conditions ... 12 
6.2 Accuracy of Measuring Instruments and Meters ... 14 
6.3 Test Process Error ... 14 
6.4 Data Recording and Recording Interval ... 14 
7 Test Preparation ... 14 
7.1 Test preparation of secondary cell ... 14 
7.2 Test Preparation of Battery Pack or System ... 15 
8 Test Methods ... 16 
8.1 Safety Test Method for Secondary Cell ... 16 
8.2 Safety Test Method for Battery Pack or System ... 19 
9 Implementation Date ... 36 
Appendix A (Informative) Typical Structure of Battery Pack or System ... 38 
Appendix B (Normative) Insulation Resistance Test Method of Battery Pack or
System ... 41 
Appendix C (Normative) Thermal Propagation Occupant Protection Analysis
and Verification Report ... 44 
Bibliography ... 50 
Electric Vehicles Traction Battery Safety
Requirements
1 Scope
This Standard specifies the safety requirements and test methods for secondary cells,
battery packs or systems of traction battery (hereinafter referred to as battery) for
electric vehicles.
This Standard is applicable to rechargeable energy storage devices for electric
vehicles, such as: li-ion battery and nickel-metal hydride battery.
2 Normative References
The following documents are indispensable to the application of this document. In
terms of references with a specified date, only versions with a specified date are
applicable to this document. In terms of references without a specified date, the latest
version (including all the modifications) is applicable to this document.
GB/T 2423.4 Environmental Testing for Electric and Electronic Products - Part 2: Test
Method - Test Db: Damp Heat, Cyclic (12 h + 12 h cycle)
GB/T 2423.17 Environmental Testing for Electric and Electronic Products - Part 2: Test
Method - Test Ka: Salt Mist
GB/T 2423.43 Environmental Testing for Electric and Electronic Products - Part 2: Test
Methods - Mounting of Specimens for Vibration Impact and Similar Dynamic Tests
GB/T 2423.56 Environmental Testing - Part 2: Test Methods - Test Fh: Vibration,
Broadband Random and Guidance
GB/T 4208-2017 Degrees of Protection Provided by Enclosure (IP code)
GB/T 19596 Terminology of Electric Vehicles
GB/T 28046.4-2011 Road Vehicles - Environmental Conditions and Testing for
Electrical and Electronic Equipment - Part 4: Climatic Loads
3 Terms and Definitions
What is defined in GB/T 19596, and the following terms and definitions are applicable
to this document.
NOTE: rated capacity is generally expressed in (Ah) or (mAh).
3.8 Practical Capacity
Practical capacity refers to the capacity value released from fully charged secondary
cell, module, battery pack or system under the conditions specified by the manufacturer.
3.9 State-of-charge
State-of-charge refers to the percentage of capacity in the current secondary cell,
module, battery pack or system that can be released in accordance with the discharge
conditions specified by the manufacturer to the practical capacity.
3.10 Explosion
Explosion refers to a sudden release of sufficient energy, which generates pressure
waves or sprays, and might cause structural or physical damage to the surrounding
area.
3.11 Fire
Fire refers to continuous combustion of secondary cell, module, battery pack or any
part of the system (the duration of single flame is greater than 1 s). Sparks and electric
arcs do not belong to combustion.
3.12 Housing Crack
Housing crack refers to mechanical damage to secondary cell, module, battery pack
or system housing due to internal and external factors, which can result in exposure or
spillage of internal substances.
3.13 Leakage
Leakage refers to the phenomenon that visible substances leak from secondary cell,
module, battery pack or system to the outside of the test object.
3.14 Thermal Runaway
Thermal runaway refers to the phenomenon of uncontrollable rise in battery
temperature caused by exothermic chain reaction of secondary cell.
3.15 Thermal Propagation
Thermal propagation refers to the phenomenon of successive thermal runaway of the
remaining secondary cells caused by thermal runaway of one secondary cell in the
battery pack or system.
3.16 End-of-charge Voltage
5.1.5 In accordance with 8.1.6, conduct temperature cycle test on secondary cell: there
shall be no fire or explosion.
5.1.6 In accordance with 8.1.7, conduct extrusion test on secondary cell: there shall be
no fire or explosion.
5.2 Safety Requirements of Battery Pack or System
5.2.1 In accordance with 8.2.1, conduct vibration test on battery pack or system: there
shall be no phenomenon of leakage, housing crack, fire or explosion. In addition,
abnormal termination conditions shall not be triggered. After the test, the insulation
resistance shall be not less than 100 /V.
5.2.2 In accordance with 8.2.2, conduct mechanical impact test on battery pack or
system: there shall be no phenomenon of leakage, housing crack, fire or explosion.
After the test, the insulation resistance shall be not less than 100 /V.
5.2.3 In accordance with 8.2.3, conduct simulated collision test on battery pack or
system: there shall be no phenomenon of leakage, housing crack, fire or explosion.
After the test, the insulation resistance shall be not less than 100 /V.
5.2.4 In accordance with 8.2.4, conduct extrusion test on battery pack or system: there
shall be no fire or explosion.
5.2.5 In accordance with 8.2.5, conduct damp heat cycle test on battery pack or system:
there shall be no phenomenon of leakage, housing crack, fire or explosion. Within 30
min after the test, the insulation resistance shall be not less than 100 /V.
5.2.6 In accordance with 8.2.6, conduct water immersion test on battery pack or system:
one of the following requirements shall be satisfies:
a) Comply with Mode 1: there shall be no fire or explosion;
b) Comply with Mode 2: after the test, IPX7 requirements must be satisfied: there
shall be no phenomenon of leakage, housing crack, fire or explosion. After the
test, the insulation resistance shall be not less than 100 /V.
5.2.7 In accordance with 8.2.7, conduct thermal stability test on battery pack or system,
excluding nickel-metal hydride battery or the system. It includes:
a) In accordance with 8.2.7.1, conduct external combustion test: there shall be
no explosion;
b) In accordance with 8.2.7.2, conduct thermal propagation occupant protection
analysis and verification. 5 min before a danger is caused in the passenger
compartment due to thermal propagation, as a result of thermal runaway of a
single battery, the battery pack or system shall provide a thermal event
independently, battery module may be adopted for testing, and the safety requirements
shall still comply with 5.1.
6.1.3 In terms of battery pack or system covered by car body and forms a battery pack
box, it may be tested along with the box or the car body.
6.1.4 Battery pack or system test delivery needs to include necessary operating
documents, as well as interface components required to connect with the test
equipment, such as: connectors and plugs, including cooling system interfaces. The
typical structure of battery pack or system is shown in Appendix A. The manufacturer
needs to provide safe operating limits for the battery pack or system.
6.1.5 Before all the tests, and after some tests, battery pack or system need to be
tested for insulation resistance. The test position is: between the two terminals and the
electric platform. It is required that the measured insulation resistance value divided by
the maximum working voltage of the battery pack or system is not less than 100 /V.
The specific test methods are shown in Appendix B.
6.1.6 If due to some reasons (for example: size or mass), battery pack or system is not
suitable for some tests, then, after reaching a consensus through negotiation, the
manufacturer and testing institution may use the subsystem of the battery pack or
system as the test object for all or some of the tests. However, the subsystem, which
serves as the test object, shall contain all the parts (for example: connecting parts or
protective parts, etc.) related to the requirements of the vehicle.
6.1.7 The method of adjusting SOC to n% of test target value: in accordance with the
charging mode provided by the manufacturer, fully charge the battery pack or system;
place it still for 1 h. Then, with 1 I3, at a constant current, discharge it for a duration of
T. T is obtained through the calculation in accordance with Formula (1). Or, adopt the
method provided by the manufacturer to adjust SOC. After each SOC adjustment,
before a new test starts, the test object shall be placed still for 30 min.
Where,
T---discharging time, expressed in (h);
n---percentage value of test target value.
6.1.8 The charging and discharging rate, method and cut-off conditions during the test
are provided by the manufacturer.
6.1.9 The rated capacity of secondary cell, battery pack or system shall comply with
the product technical conditions provided by the manufacturer.
Firstly, at the current specified by the manufacturer and not less than 1 I3, discharge
secondary cell to the discharge cut-off voltage specified by the manufacturer in the
technical conditions. Place it still for 1 h (or, the shelving time provided by the
manufacturer and not more than 1 h). Then, in accordance with the charging method
provided by the manufacturer, charge the secondary cell. After charging, place it still
for 1 h (or, the shelving time provided by the manufacturer and not more than 1 h).
If the manufacturer does not provide charging method, then, the testing institution and
the manufacturer shall negotiate and determine an appropriate charging method, or
charge in accordance with the following methods:
At a constant current specified by the manufacturer and not less than 1 I3, charge the
secondary cell, till it reaches the charge cut-off voltage specified by the manufacturer
in the technical conditions, then, transfer to constant-voltage charging, till the charging
current drops to 0.05 I1, then, stop charging. After charging, place it still for 1 h (or, the
shelving time provided by the manufacturer and not more than 1 h).
7.1.2 Pre-treatment
7.1.2.1 Before the official test starts, secondary cell needs to undergo a pre-treatment
cycle first, so as to ensure that the performance of the test object is activated and
stable. Proceed as follows:
a) In accordance with 7.1.1, conduct standard charging on the secondary cell;
b) At a current specified by the manufacturer and not less than 1 I3, discharge to
the discharge cut-off conditions specified by the manufacturer;
c) Place it still for 30 min, or the time specified by the manufacturer;
d) Repeat a) ~ c) for not more than 5 times.
7.1.2.2 If discharging capacity change of the secondary cell in consecutive two times
is not higher than 3% of the rated capacity, then, it is believed that the secondary cell
has completed the pre-treatment, and the pre-treatment cycle can be terminated.
7.2 Test Preparation of Battery Pack or System
7.2.1 Confirmation of working status
Before the official test starts, the electronic components or BCU of the battery pack or
system shall be in normal working status.
7.2.2 Pre-treatment
7.2.2.1 Before the official test starts, battery pack or system needs to undergo a pre-
treatment cycle first, so as to ensure that the performance of the test object is activated
and stable. Proceed as follows:
8.1.3 Over-charge
8.1.3.1 Test object is secondary cell.
8.1.3.2 In accordance with 7.1.1, charge the test object.
8.1.3.3 With a constant current specified by the manufacturer and not less than 1 I3,
charge to 1.1 times of the charge cut-off voltage specified by the manufacturer or 115%
SOC, then, stop charging.
8.1.3.4 After completing the above test procedures, at the ambient temperature of test,
observe for 1 h.
8.1.4 External short-circuit
8.1.4.1 Test object is secondary cell.
8.1.4.2 In accordance with 7.1.1, charge the test object.
8.1.4.3 Externally short-circuit the positive and negative terminals of the test object for
10 min: the electrical resistance of the external circuit shall be less than 5 m.
8.1.4.4 After completing the above test procedures, at the ambient temperature of test,
observe for 1 h.
8.1.5 Heating
8.1.5.1 Test object is secondary cell.
8.1.5.2 In accordance with 7.1.1, charge the test object.
8.1.5.3 Place the test object into a temperature box; use the following conditions for
heating:
a) Li-ion secondary cell: at the rate of 5 °C/min, raise the temperature box from
the ambient temperature of test to 130 °C ± 2 °C; maintain this temperature
for 30 min, then, stop heating;
b) Nickel-metal hydride battery: at the rate of 5 °C/min, raise the temperature
box from the ambient temperature of test to 85 °C ± 2 °C; maintain this
temperature for 2 h, then, stop heating.
8.1.5.4 After completing the above test procedures, at the ambient temperature of test,
observe for 1 h.
8.1.6 Temperature cycle
8.1.6.1 Test object is secondary cell.
8.1.7.3 In accordance with the following conditions, conduct the test:
a) Extrusion direction: apply pressure perpendicular to the dire...