GB 38031-2025Electric vehicles traction battery safety requirements (English PDF)

4.1 Symbols

The following symbols apply to this document. […]

4.2 Abbreviations

The following abbreviations apply to this document.

5.1 Safety requirements for battery cells

5.2 Safety requirements for battery pack or system

5.2.1 The battery pack or system shall be subjected to vibration test in accordance with 8.2.1; it shall not have leakage, housing crack, fire or explosion. The insulation resistance after the test shall be not less than 100 Ω/V. If there is an AC circuit, the insulation resistance shall be not less than 500 Ω/V. 5.2.2 The battery pack or system shall be subjected to mechanical impact test in accordance with 8.2.2; it shall not have leakage, housing crack, fire or explosion. The insulation resistance after the test shall be not less than 100 Ω/V. If there is an AC circuit, the insulation resistance shall be not less than 500 Ω/V. 5.2.3 The battery pack or system shall be subjected to a simulated collision test in accordance with 8.2.3; there shall be no leakage, housing crack, fire or explosion. The insulation resistance after the test shall be no less than 100 Ω/V. If there is an AC circuit, the insulation resistance shall be no less than 500 Ω/V. shall be no less than 100 Ω/V. If there is an AC circuit, the insulation resistance shall be no less than 500 Ω/V. 5.2.5 The battery pack or system shall be subjected to a damp heat cycle test in accordance with 8.2.5; there shall be no leakage, housing crack, fire or explosion. The insulation resistance within 30 minutes after the test shall be no less than 100 Ω/V. If there is an AC circuit, the insulation resistance shall be no less than 500 Ω/V. a) According to method 1, no fire or explosion shall occur; b) According to method 2, after the test, it shall meet the IPX7 requirements of GB/T 4208-2017, and there shall be no leakage, housing crack, fire or explosion. […]

6.1 General conditions

6.1.1 Unless otherwise specified, the test environment temperature is 22 °C ± 5 °C, the relative humidity is 10% ~ 90%, the atmospheric pressure is 86 kPa ~ 106 kPa. 6.1.2 If the test object is a battery cell, it can be tested with a fixture. If the battery cell cannot work independently, the battery module shall be used for testing; the safety requirements of 5.1 shall be met. 6.1.3 For battery packs or systems that are covered by a body frame and constitute the battery pack box, they can be tested with the box or body frame. 6.1.4 The test delivery of the battery pack or system shall include the necessary operating documents and the interface components required for connection to the test equipment, such as connectors, plugs, cooling system interfaces. The typical structure of the battery pack or system is shown in Appendix A. In addition, additional sensors, wires, fixtures shall not affect the test results. The manufacturer shall provide the safe working limits of the battery pack or system. 6.1.5 The battery pack or system shall be tested for insulation resistance before all tests and after some tests. The test location is between the positive-negative output terminals and the electrical platform. The specific test method shall be carried out in accordance with Appendix B. 6.1. […]

6.2 Accuracy of measuring instruments and meters

The accuracy of measuring instruments and meters shall not be less than the following requirements:

6.3 Test process error

The error requirements between the control value (actual value) and the target value are as follows:

7.1 Preparation for battery cell test

7.1.1 Standard charging

Discharge at a current specified by the manufacturer and not less than 1I3 to the end-ofdischarge voltage specified in the manufacturer's technical conditions; let it stand for 1 hour (or the standing time provided by the manufacturer not more than 1 hour); then charge according to the charging method provided by the manufacturer; […]

7.1.2 Pretreatment

7.1.2.1 Before the formal test begins, the battery cell shall be preconditioned first. The steps are as follows:

a) Perform standard charging on the battery cell according to 7.1.1;

b) Discharge at a current specified by the manufacturer and not less than 1 I3 to the end-of-discharge condition specified by the manufacturer;

d) Repeat steps a) ~ c) for no more than 5 cycles.

7.1.2.2 If the extreme difference of the discharge capacity of the battery cell is less than 3% of the rated capacity for 3 consecutive times, the battery cell is deemed to have completed the pretreatment; the pretreatment cycle can be terminated; the average of the last 3 test results is taken as the actual capacity.

7.2 Preparation for battery pack or system test

7.2.1 Confirmation of working status

Before the formal test begins, the battery electronic components or BCU shall be in normal working condition.

7.2.2 Pretreatment

7.2.2.1 Before the formal test begins, the battery pack or system shall be preconditioned. The steps are as follows: a) Charge at a current of not less than 1 I3 or according to the charging method recommended by the manufacturer to the end-of-charge condition specified by the manufacturer; b) Let it stand for 30 min or the time specified by the manufacturer; c) Discharge at a current specified by the manufacturer and not less than 1 I3 to the end-of-discharge condition specified by the manufacturer; d) Let it stand for 30 min or the time specified by the manufacturer; […]

8.1 Test methods for battery cell safety

8.1.1 General requirements

All safety tests are conducted under environmental conditions with adequate safety protection. If the test object has additional active protection circuits or devices, they shall be removed.

8.1.2 Over-discharge

8.1.2.1 The test object is a battery cell.

8.1.2.2 Adjust the state of charge of the test object to the end-of-discharge voltage state; […]

8.1.3 Over-charge

8.1.3.1 The test object is a battery cell.

8.1.3.3 Stop charging after charging at a constant current of not less than 1 I3 specified by the manufacturer to 1.1 times the end-of-charge voltage specified by the manufacturer or 115% SOC.

8.1.3.4 After completing the above test steps, observe at the test environment temperature for 1 hour.

8.1.4 External short circuit

8.1.4.1 The test object is a battery cell.

8.1.4.4 After completing the above test steps, observe at the test environment temperature for 1 hour.

8.1.5 Heating

8.1.5.1 The test object is a battery cell.

8.1.5.3 Place the test object in a temperature box. For test objects other than nickelmetal hydride battery cells, the temperature box is raised from the test environment temperature to 130 °C at a rate of 5 °C/min; the temperature is maintained for 30 minutes before stopping heating. For nickel-metal hydride battery cells, the temperature box is raised from the test environment temperature to 85 °C at a rate of 5 °C/min; the temperature is maintained for 2 hours before stopping heating.

8.1.5.4 After completing the above test steps, observe at the test environment temperature for 1 hour.

8.1.6 Temperature cycle

8.1.6.1 The test object is a battery cell.

8.1.6.3 Place in a temperature box; adjust the temperature of the temperature box according to Table 1 and Figure 1; […]

8.1.7 Extrusion

8.1.7.1 The test object is a battery cell.

direction, or in the same direction as the battery cell which is most susceptible to extrusion in the vehicle layout; semi-cylinder (L) is greater than the size of the extruded battery cell (as shown in Figure 6); c) Extrusion speed: No more than 2 mm/s; reaches 15% or the extrusion force reaches 100 kN or 1000 times the weight of the test object; […]

8.2 Battery pack or system safety test method

8.2.7 Thermal stability

8.2.11 Overtemperature protection

8.2.13 External short-circuit protection

8.2.14 Overcharge protection

8.2.15 Over-discharge protection