GB/T 46991.1-2025Requirements and test methods for the durability of in-vehicle traction batteries of electric vehicles - Part 1: Light-duty vehicles (English PDF)

3.1 Usable battery energy (UBE)

In a range test, the energy supplied by the battery from the start to the end of the test.

3.2 Certified usable battery energy (UBE certified)

The change in electrical energy obtained during type certification, according to the test methods of GB/T 18386.1-2021 and GB/T 19753-2021.

3.3 Measured usable battery energy (UBE measured)

The change in electrical energy measured at the current point in the vehicle's lifecycle, according to the test methods of GB/T 18386.1-2021 and GB/T 19753-2021.

3.4 Certified battery electric range (BER certified)

The type certification value for the driving range determined according to the test methods of GB/T 18386.1-2021 and GB/T 19753-2021.

3.5 Measured battery electric range (BER measured)

The vehicle's driving range measured at the current node, according to the test methods of GB/T 18386.1-2021 and GB/T 19753-2021.

3.6 State of certified energy (SOCE)

[Source: GB/T 29317-2021, 10.1]

4.1 General requirements

4.1.1 Vehicles shall be equipped with diagnostic interfaces conforming to GB 18352.6-2016 (or other applicable versions).

4.1.2 Externally pluggable hybrid electric vehicles (OVC-HEVs) shall comply with the relevant requirements of SAE J1979 or SAE J1979-2.Battery electric vehicles (BEVs) shall comply with the relevant requirements of SAE J1979-3.

4.1.3 Vehicles shall have SOCE and SOCR monitoring functions; continuously monitor and update SOCE, SOCR, and other data in Appendix A throughout their entire life cycle.

4.1.4 SOCE and SOCR shall be expressed as percentages, ranging from 0 to 100%, rounded to one percentile.

4.1.5 The vehicle manufacturer or its authorized agent shall provide the latest onboard SOCE and SOCR values through the On-board Diagnostic (OBD) system port; it may also provide them via Over-The-Air (OTA) transmission. The vehicle manufacturer or its authorized agent shall provide users with at least one method to obtain SOCE values, ensuring that the values obtained by users are consistent with those of relevant regulatory authorities. Examples include:

- Dashboard indication;

- On-board infotainment system;

- Remote access (e.g., via mobile application).

4.1.6 Over the vehicle's ten-year or 200000 km lifespan, the onboard power battery shall meet the requirements of 4.2 and 4.3.

4.2 Accuracy requirements

4.2.1 For SOCE accuracy, the difference between SOCEread and SOCEmeasured shall not exceed 5%, i.e., the result of SOCEread minus SOCEmeasured shall be less than or equal to 5%.

4.2.2 For virtual distance accuracy, the relative deviation between the onboard virtual distance and the measured virtual distance shall not exceed 3%.

5.1 Test vehicle

The test vehicle can be run-in according to the manufacturer's recommended method, with a run-in mileage of not less than 300 km and not exceeding 5000 km. After the run-in is completed, vehicle pretreatment can be performed according to the manufacturer's requirements.

Other requirements shall comply with the provisions of GB/T 18386.1-2021 and GB/T 19753-2021.

5.2 Test methods

5.2.1 General requirements

5.2.1.1 For pure electric vehicles, the driving range (BER) and usable battery energy (UBE) shall be obtained according to GB/T 18386.1-2021, where UBE is the change in electrical energy described in 7.3.1 and 7.3.2 of GB/T 18386.1-2021, calculated according to Appendix B.

5.2.1.2 For plug-in hybrid electric vehicles, BER and UBE shall be obtained according to GB/T 19753-2021, where BER is the equivalent all-electric range (EAER); UBE is calculated according to Appendix B.

5.2.2 Initial test

The test shall be conducted according to the requirements of 5.2.1 to obtain the vehicle's UBE and BER.

5.2.3 Verification test

The aging and degradation test of the on-board power battery of the electric vehicle shall be conducted according to Appendix C. When one of the following conditions is met, the usable battery energy (UBE) test shall be conducted according to the requirements of 5.2.1, to obtain the corresponding UBE measured at the endurance mileage; the corresponding SOCEread shall be recorded. Before the verification test begins, the manufacturer may conduct a vehicle pretreatment test.

a) For pure electric vehicles.

1) SOCEread is not greater than 99% and the vehicle's cumulative mileage is not less than 20000 km;

2) The vehicle's cumulative mileage reaches 50000 km.

b) For plug-in hybrid electric vehicles that meet GB/T 32694 or GB/T 34598.

1) SOCEread is not greater than 99% and the vehicle's cumulative mileage is not less than 15000 km;

2) The vehicle's cumulative mileage reaches 30000 km.

c) For plug-in hybrid electric vehicles that do not meet GB/T 32694 or GB/T 34598.

1) SOCEread is not greater than 99% and the vehicle's cumulative mileage is not less than 5000 km;

2) The vehicle's cumulative mileage reaches 10000 km.

5.3 Calculation of results

5.3.1 SOCEmeasured is obtained by measuring the available energy of the battery and dividing it by the available energy of the certified battery, expressed as a percentage. SOCEmeasured is calculated according to formula (2). Where:

SOCEmeasured - Stated of measured usable battery energy, rounded to one decimal place;

UBEmeasured - Measured usable battery energy, rounded to the nearest integer, in watt-hours (Wh);

UBEcertified - Certified usable battery energy, rounded to the nearest integer, in watt-hours (Wh).

If UBEmeasured is higher than UBEcertified, then SOCEmeasured shall be 100%.

5.3.2 SOCRmeasured is obtained by dividing the measured driving range by the certified driving range, expressed as a percentage. SOCRmeasured is calculated according to formula (3). Where:

SOCRmeasured - Measured state of certified range, rounded to one decimal place;

BERmeasured - Measured battery electric range, rounded to the nearest integer, in kilometers (km);

BERcertified - Certified battery electric range, rounded to the nearest integer, in kilometers (km).

If BERmeasured is higher than BERcertified, then SOCRmeasured shall be 100%.

5.4 Judgment method

After the first UBE test at the corresponding mileage node, if the difference between SOCEread (after the test) and SOCEmeasured does not exceed 5%, the test vehicle passes the accuracy verification. Otherwise, a second UBE test shall be conducted.

After the second UBE test, the arithmetic mean of the two SOCEread and SOCEmeasured tests is calculated. If the difference between the arithmetic means does not exceed 5%, the test vehicle passes the accuracy verification. Otherwise, a third UBE test is conducted.

After the third UBE test, the arithmetic mean of the three SOCEread and SOCEmeasured tests is calculated. If the difference between the arithmetic means does not exceed 5%, the test vehicle passes the accuracy verification. Otherwise, it fails.

6.1 General requirements

6.1.1 When the manufacturer requires the use of virtual distance, the reported virtual distance needs to be verified.

6.1.2 To verify the accuracy of the virtual distance in the vehicle system, the vehicle shall be tested under V2X or non-traction purposes (if applicable), to verify the accuracy of the virtual distance provided by the vehicle system. The testing items shall include all V2X functions, such as two-way charging and discharging interaction between electric vehicle and the grid (V2G), two-way charging and discharging interaction between electric vehicle and residence (V2H), charging and discharging between electric vehicles (V2V), electric vehicle supplying power to a load (V2L).

During the measurement, the total discharge amount used for non-traction purposes shall be recorded to calculate the measured virtual distance.

6.2 Test method

6.2.1 The test chamber temperature shall be set to 23 °C, with an allowable deviation of ±5 °C.

6.2.2 Before the test, the vehicle's SOC shall not be lower than 95%.

6.2.3 During the test, only a single V2X function shall be activated; the external discharge power shall be set to the maximum discharge power. Discharge shall be continued for 2 hours and then stopped (or discharged to the cutoff voltage); the […]