GB/T 44257.2-2024Traction batteries for electric earth-moving machinery - Part 2: Electrical performance requirements (English PDF)

5.2 Battery pack or battery system

5.2.1 Appearance The battery pack or battery system shall be tested according to 7.2.1. The appearance shall be free of deformation and cracks. The surface shall be dry, free of burrs, external injuries and dirt. It shall also have clear and correct markings.

5.2.2 Dimensions and mass The battery pack or battery system shall be tested according to 7.2.2. The dimensions and mass shall comply with the product technical requirements provided by the manufacturer.

5.2.3 Room temperature discharge capacity The battery pack or battery system shall be tested according to 7.2.4. The initial capacity shall not be less than the rated capacity and shall not exceed 110% of the rated capacity. The room temperature discharge energy shall not be less than the rated energy.

5.2.4 Energy efficiency The battery pack or battery system shall be tested according to 7.2.4. The energy efficiency shall not be less than 90%.

6.1 General conditions

6.1.1 Unless otherwise specified, the test shall be conducted in an environment at a temperature of 25 °C ± 2 °C, a relative humidity of 10% ~ 90%, an atmospheric pressure of 86 kPa ~ 106 kPa.

6.1.2 When the test target ambient temperature changes, the environmental adaptation process shall be completed before the test: the difference between the battery cell temperature and the target ambient temperature shall not exceed 2 °C; the battery cell temperature change rate shall be less than 1 °C/h within at least 30 min.

6.1.3 The high and low temperature test chamber shall meet the requirements of GB/T 10592; or refer to Appendix A to use the test fixture.

6.1.4 Before the test, the manufacturer shall provide parameters such as rated capacity, rated energy, discharge termination voltage.

6.1.5 During the test, the thermal management system of the battery pack or battery system works according to the manufacturer's requirements or the instructions of the battery management system; the on or off status of the thermal management system shall be clearly stated in the test report.

6.1.6 The test procedure and the number of samples required refer to Table B.1 in Appendix B.

6.2 Accuracy of measuring instruments and meters The accuracy of measuring instruments and meters shall meet the following requirements: If the manufacturer does not provide a charging method, charge at a constant current of no less than 1I3 specified by the manufacturer to the charging termination voltage, which is specified by the manufacturer. Switch to constant voltage charging, until the charging current drops to 0.15I3. After charging, let it stand for 1 hour (or a standing time of no more than 1 hour provided by the manufacturer).

7.1.4 Room temperature discharge capacity The room temperature discharge capacity is carried out according to the following steps:

a) Charge the battery cell according to the method in 7.1.3;

b) At room temperature, discharge the high-energy batteries at a current of 1I3 and high-power batteries at a current of 1I1, until the discharge reaches the discharge termination voltage specified by the manufacturer;

c) Measure the discharge capacity (Ah); calculate the discharge energy (Wh) and discharge specific energy (Wh/kg);

c) for 5 times. When the range of the results of 3 consecutive tests is less than 3% of the rated capacity, the test can be terminated in advance; take the average of the last 3 test results as the initial capacity.

7.1.5 Room temperature rate discharge performance

7.1.5.1 High energy batteries 7.1.5.1.1 The data recording interval of the room temperature rate discharge capacity test shall not exceed 100 ms. 7.1.5.1.2 The room temperature rate discharge capacity test is carried out according to the following steps:

a) Charge the battery cell according to the method in 7.1.3;

b) At room temperature, discharge the battery cell at a current of 3I3, until it reaches the discharge termination voltage specified by the manufacturer;

c) Measure the discharge capacity (Ah).

7.1.5.2 High-power batteries 7.1.5.2.1 The data recording interval of the room temperature rate discharge capacity test shall not exceed 100 ms. 7.1.5.2.2 The room temperature rate discharge capacity test is carried out according to the following steps:

a) Charge the battery cell according to the method of 7.1.3;

b) At room temperature, discharge the battery cell at a current of 10I1 (maximum current not exceeding 800 A), until it is discharged to the discharge termination voltage specified by the manufacturer;

c) Measure the discharge capacity (Ah).

7.1.6 Room temperature rate charging performance Test the room temperature rate charging performance according to the following steps:

a) At room temperature, discharge the high energy type batteries at a current of 1I3 and high power type batteries at a current of 1I1, until they are discharged to the discharge termination voltage specified by the manufacturer; let it stand for 1 hour;

b) At room temperature, charge the battery cells to the charge termination voltage specified by the manufacturer, according to the charging strategy specified by the manufacturer, or the charge termination conditions specified by the manufacturer; the total charging time does not exceed 30 minutes; let it stand for 1 hour;

c) At room temperature, discharge the high energy type batteries at a current of 1I3 and high power type batteries at a current of 1I1, until they are discharged to the discharge termination voltage specified by the manufacturer;

d) Measure the discharge capacity (Ah).

7.1.7 Low-temperature discharge capacity The low-temperature discharge capacity test is carried out according to the following steps:

7.2 Battery pack or battery system

7.2.1 Appearance Under good light conditions, visually inspect the appearance of the battery pack or battery system.

7.2.2 Dimensions and mass Measure the dimensions and mass of the battery pack or battery system with measuring instruments and scales.