NB/T 33024-2016Test specification for lithium-ion traction battery of Electric Vehicles (English PDF)

5.4.3 Over-discharge protection

When the battery box/battery system is subject to the over-discharge protection test in accordance with the provisions of 6.5.4, the test sample protection element shall operate reliably and the battery box/battery system shall be free from fire, explosion and leakage.

5.4.4 Short circuit protection

When the battery box/battery system is subject to the short-circuit protection test in accordance with the provisions of 6.5.5, the short-circuit current is cut off by the overcurrent protection device or the line is automatically cut off. The battery box/battery system shall be free from fire, explosion, and leakage.

5.4.5 Overload protection

When the battery box/battery system is subject to the overload protection test in accordance with 6.5.6, when the battery box/battery system discharge current reaches the overload protection current value, an alarm signal shall be issued and the circuit cut off. The storage tank/battery system shall be free from fire, explosion, or liquid leakage; after troubleshooting, it shall have a recovery function.

5.4.6 High temperature working test

When the battery box/battery system is subject to a high temperature working test in accordance with 6.5.7, the temperature of the battery modules (including the battery cells) in the test sample shall not exceed the battery temperature limit.

5.4.7 Low temperature working test

When the battery box/battery system is tested in accordance with 6.5.8 for low temperature working test, the system shall be charged and discharged normally.

The capacity of the sample system shall comply with the requirements of the enterprise. The temperature and voltage of the battery modules (including the battery cell) in the test sample shall not exceed the working limits.

5.4.8 Temperature control system failure test

When the battery box/battery system is subject to a temperature control system failure test in accordance with 6.5.9, the battery shall be free from fire, explode or liquid leakage.

5.4.9 Working condition test

6.5.2 Room temperature discharge capacity (initial capacity)

a) The battery box/battery system is charged in accordance with the method of 6.5.1.

b) After it is full charged, the fully charged battery box/battery system is allowed to stand for 2 h or more, and then discharged to the discharge termination voltage at a certain rate of current [energy type 1I2 (A), power type 1I1 (A)].

c) Use discharge current value and discharge time data to calculate the capacity (in Ah); use discharge current value, discharge voltage and discharge time data to calculate the energy (Wh or kWh).

d) The calculated value is lower than the rated value, it can be repeated once.

6.5.3 Overcharge protection

a) The battery box/battery system is charged in accordance with 6.5.1.

b) Set the constant current and constant voltage source voltage to 1.2 times the maximum voltage of the test sample.

c) The test sample (within 24 h after full charging) continues to be charged at the maximum continuous current specified by the enterprise's technical requirements. If the voltage of a single cell exceeds the charging termination voltage or exceeds the normal protection time limit, the charging process shall be automatically interrupted.

d) After the test, make observation for 2 h.

6.5.4 Over-discharge protection

a) The battery box/battery system is charged in accordance with 6.5.1.

b) The test sample is discharged at a certain rate of current [energy type 1I2 (A), power type 1I1 (A)].

c) If the voltage of a battery cell is lower than the discharge termination voltage, or exceeds the normal protection time limit, the discharge process shall be automatically interrupted.

d) After the test, make observation for 2 h.

6.5.5 Short-circuit protection

a) The battery box/battery system is charged in accordance with 6.5.1.

b) Short-circuit the positive and negative electrodes of the test sample using

6.5.9 Temperature control system failure test

a) At room temperature, the battery box/battery system discharges at a certain rate current [energy type 1I2 (A), power type 1I1 (A)] to the discharge termination state.

b) Turn off the temperature control system on the battery box/battery system.

c) The fully discharged battery box/battery system is placed at the maximum working temperature given by the company for 7 hours, the charging is stopped after charging fully at the maximum current allowed by the enterprise or the protection device actions.

d) Allow it to stand at room temperature for 7 h.

e) The battery box/battery system is charged in accordance with 6.5.1.

f) Fully-charged battery box/battery system shall be placed at the maximum working temperature for 7 hours, the charging is stopped after charging to the minimum discharge voltage as specified by the enterprise at the maximum discharge current allowed by the enterprise or the protection device actions.

6.5.10 Working condition test

The working condition test is performed in accordance with the provisions of Appendix A.

6.5.11 Battery management system accuracy

6.5.11.1 Voltage accuracy

Use the voltage measuring device to measure the voltage of the battery box and the battery module (the number of cell or module voltage collection channel is not less than 5), respectively compare it with the battery box and battery module voltages displayed by the BMS. The result shall meet the requirements of 5.4.10.

6.5.11.2 Current accuracy

The battery box/system is discharged with a certain current (I5/I2/I1). Use the current measuring device to measure the discharge current, compare it with the discharge current displayed by the battery box/battery system BMS. The result shall meet the requirements of 5.4.10.

6.5.11.3 Temperature accuracy

The battery box/system is charged in accordance with 6.5.1. Use the […]

6.5.14.3 Radiated disturbance limit

Test methods shall be carried out in accordance with GB/T 18655-2010, and the results shall meet the requirements of 5.4.13.

6.5.14.4 Surge (impact) immunity

The test method shall be carried out in accordance with GB/T 17626.5-2008, and the results shall meet the requirements of 5.4.13.

6.5.15 Mechanical shock

a) The battery module is fully charged in accordance with 6.5.1.

b) The battery module is fixed on the test equipment in accordance with the actual vibration acceleration direction of the electric vehicle, and the mechanical impact is scanned in accordance with the following conditions.

- Pulse mode. sine half wave.

- Maximum acceleration. 500 m/s².

- Duration. 6 ms.

- 10 repetitions.

6.5.16 Vibration

a) The battery box/battery system is charged in accordance with 6.5.1.

b) Fasten the fully charged test sample to the vibration test bench with the rigid fasteners in the normal working direction of the vehicle and perform the linear sweep vibration test in accordance with the following conditions.

- Discharge current. 1I2 (A).

- Vibration direction. single vibration up and down.

- Frequency 10 Hz ~ 55 Hz.

- Maximum acceleration. 30 m/s².

- Sweep cycle. 10 times.

- Vibration time. 120 ± 5 min.

c) Observe any abnormalities during the vibration test.

6.5.17 Water immersion

A.1 Scope

This appendix specifies the test method for the working condition cycle life of the power battery box/battery system for electric vehicles.

A.2 Test conditions

A.2.1 Method of adjusting SOC to n% of test target value

a) The test sample shall be charged in accordance with the text 6.5.1.

b) Energy type power battery sample are discharged at a constant current of 1I2 for 2 × (100-n)/100 h, the power type power battery sample is discharged at a constant current of I1 (100-n)/100 h.

A.2.2 Power test methods

a) Test sample SOC is adjusted in accordance with the method of A.2.1 to 50%.

b) Allow to stand for 30 minutes.

c) Discharge at the maximum discharge current specified by the enterprise for 5 s. After the test, the battery is discharged at a certain rate current [energy type 1I2 (A), power type 1I1 (A)] to any single cell voltage to reach the discharge termination voltage.

d) Calculate the power of the last data acquisition point in step c).

A.3 Working condition test

A.3.1 Energy type battery for pure electric passenger vehicle

The cycle test consists of two parts. The charging part is carried out in accordance with the text 6.5.1, the discharging part is performed in accordance with the "main discharge conditions" shown in Figure A.1 and Table A.1, the entire test procedure is shown in Table A.2, the SOC fluctuations formed by the main discharge conditions are as shown in Figure A.2.

B.1 Requirements

B.1.1 Assemble the tested battery system in accordance with the normal

working requirements (it can choose the minimum battery system applicable to the battery management system).

B.1.2 Before the available capacity testing of B.2, the test sample shall be allowed to stand for at least 16 h at the test temperature. While standing, the battery and management system are in a non-operational state.

B.2 Available capacity test

a) Discharge at 1I3 (A) current until the cell (module) voltage of the battery system reaches the discharge termination voltage or the total voltage reaches the discharge termination voltage.

b) Let stand for 1 h.

c) Charge at a constant current of 1I3 (A) until the cell (module) voltage of the battery system reaches the charge termination voltage or the total voltage reaches the charge termination voltage.

d) Charge at constant voltage, the charging current is reduced to I9 (A) or other termination conditions specified by the enterprise's technical requirements.

e) Let stand for 1 h.

f) Discharge by the discharge specification a) and record the total discharge Q01 of the discharge process.

g) Repeat b) ~ f) twice, record the discharge capacity as Q02 and Q03, respectively. The average of the three discharge capacities is Q0. If the deviations of Q01, Q02 and Q03 from Q0 are less than 2%, Q0 is the available capacity of the battery system. If the deviation between Q01, Q02 and Q03 from Q0 is not less than 2%, the available capacity test process needs to be repeated until the discharge capacity for three consecutive times meets the conditions for the available capacity confirmation.

Note: If the manufacturer has recommended charging and discharging […]