GB/T 31485-2015Safety requirements and test methods for traction battery of electric vehicle (English PDF)

5.1 Secondary cell

5.1.1 When over-discharge test in sub-clause 6.2.2 is carried out on secondary cell, there

shall have no explosion, fire or leakage.

5.1.2 When over-charge test in sub-clause 6.2.3 is carried out on secondary cell, there

shall have no explosion and fire.

5.1.4 When dropping test in sub-clause 6.2.5 is carried out on secondary cell.

a) For lithium battery, there shall have no explosion, fire and leakage;

b) For nickel-metal hydride battery, there shall have no explosion and fire.

5.1.5 When heating test in sub-clause 6.2.6 is carried out on secondary cell, there shall

have no explosion or fire.

5.1.6 When crushing test in sub-clause 6.2.7 is carried out on secondary cell, there shall

have no explosion or fire.

5.1.7 When puncturing test in sub-clause 6.2.8 is carried out on secondary cell, there shall

have no explosion or fire.

5.1.8 When sea water immersion test in sub-clause 6.2.9 is carried out on secondary cell, there shall have no explosion or fire.

5.1.9 When temperature cycle test in sub-clause 6.2.10 is carried out on secondary cell, there shall have no explosion, fire or leakage.

5.1.10 When low atmospheric pressure test in sub-clause 6.2.11 is carried out on secondary cell, there shall have no explosion, fire or leakage.

5.2 Battery module

5.2.1 When over-discharge test in sub-clause 6.3.2 is carried out on battery module, there

shall have no explosion, fire or leakage.

5.2.2 When over-charge test in sub-clause 6.3.3 is carried out on battery module, there

shall have no explosion and fire.

5.2.4 When dropping test in sub-clause 6.3.5 is carried out on battery module.

a) For lithium battery, there shall have no explosion, fire and leakage;

b) For nickel-metal hydride battery, there shall have no explosion and fire.

6.1 Test conditions

6.1.1 Environmental conditions

Unless otherwise specified, the test shall be conducted at the temperature of 25°C ± 5°C, relative humidity of 15%~90% and atmospheric pressure of 86 kPa~106 kPa. The room temperature referred in this Standard means 25°C ± 2°C.

6.1.2 Precision of measuring instrument and apparatus

The precision of measuring instrument and apparatus shall conform to the following requirements.

6.1.3 Secondary cell charging

Under room temperature, secondary cell is discharged at the current of 1I1 (A) until it reaches to the final voltage as specified in the technical conditions of manufacturer. Put it aside for 1 h (or less than 1 h as specified by manufacturer); then charge the secondary cell according to the method provided by manufacturer.

If manufacturer does not provide charging method, the following method can be adopted.

a) As to lithium ion battery, charge it at the constant current of 1I1 (A) and then change to constant-voltage charge when it reaches to the final voltage as specified in the technical conditions. When the charging current falls to 0.05I1 (A), charging shall be stopped. Put it aside for 1 h (or less than 1 h as specified by manufacturer);

b) As to metal hydride nickel battery, charge it at the constant current of 1I1 (A) for 1 h and then charge it at the constant current of 0.2I1 (A) for 1 h. Put it aside for 1 h (or less than 1 h as specified by manufacturer).

6.1.4 Battery module charging

Under room temperature, battery module is discharged at the current of 1I1 (A) until it reaches to the final voltage as specified in the technical conditions of manufacturer. Put it aside for 1 h (or less than 1 h as specified by manufacturer) and then charge the battery module according to the method provided by manufacturer.

If manufacturer does not provide charging method, the following method can be adopted.

a) As to lithium ion battery, charge it at the constant current of 1I1 (A) and then change to constant-voltage charge when it reaches to the final voltage as specified in the technical conditions. When the charging current falls to 0.05I1 (A), charging shall be stopped. Put it aside for 1 h (or less than 1 h as specified by manufacturer);

b) As to metal hydride nickel battery, charge it at the constant current of 1I1 (A) for 1 h and then charge it at the constant current of 0.2I1 (A) for 1 h. Put it aside for 1 h (or less than 1 h as specified by manufacturer).

6.2 Safety test of secondary cell

6.2.1 General requirements

All test items shall be carried out with sufficient safety protection measures. If the test objective has additional active protection circuit or apparatus, it shall be removed.

6.2.2 Over-discharging test

Over-discharging test shall be carried out according to the following procedure.

a) Charge secondary cell according to the method in sub-clause 6.1.3;

b) Discharge secondary cell at 1I1(A) current for 90 min;

c) Observe it for 1h.

6.2.3 Over-charging test

Over-charging test shall be carried out according to the following procedure.

a) Charge secondary cell according to the method in sub-clause 6.1.3;

b) Charge at constant current of 1I1(A) and terminate when the voltage reaches 1.5 times of charging termination voltage specified by manufacturer or the charging duration reaches 1h;

c) Observe it for 1h.

6.2.4 Short-circuit test

Short-circuit test shall be carried out according to the following procedures.

a) Charge secondary cell according to the method in sub-clause 6.1.3;

b) Short-circuit the positive and negative poles of the secondary cell externally for 10min and the external circuit resistance shall be less than 5mohm;

c) Observe it for 1h.

6.2.5 Dropping test

Dropping test shall be carried out according to the following procedure.

a) Charge secondary cell according to the method in sub-clause 6.1.3;

b) Drop the secondary cell with positive and negative terminals downward from 1.5m height to cement floor;

c) Observe it for 1h.

6.2.6 Heating test

Heating test shall be carried out according to the following procedure.

a) Charge secondary cell according to the method in sub-clause 6.1.3.

b) Place secondary cell in temperature chamber.

-- For lithium battery, increase the temperature at 5°C/min rate until it reaches 130°C±2°C; maintain it for 30min; then stop heating.

-- For nickel-metal hydride battery, increase the temperature at 5°C/min rate until it reaches 85°C±2°C; maintain it for 2h; then stop heating.

c) Observe it for 1h.

6.2.7 Crushing test

Crushing test shall be carried out according to the following procedure.

a) Charge secondary cell according to the method in sub-clause 6.1.3.

b) Carry out test according to the following conditions.

— Crushing direction. apply pressure along the direction perpendicular to battery pole plate (as shown in Figure 1) — Crushing plate form. semi-cylinder with 75mm radius and length (L) greater than the size of battery to be crushed.

— Crushing speed. (5±1)mm/s;

— Crushing degree. stop crushing when the voltage is 0V or deformation reaches 30% or the crushing force reaches 200kN.

c) Observe it for 1h.

Figure 1 Crushing plate and crushing illustration for secondary cell

6.2.8 Puncturing test

Puncturing test shall be carried out according to the following procedure.

a) Charge secondary cell according to the method in sub-clause 6.1.3;

b) Penetrate the secondary cell along the direction perpendicular to battery pole plate at (25±5)mm/s speed by using high temperature resistance steel needle with diameter of phi5mm~phi8mm (the coning angle of needle point is 45°~60° and the surface of needle is clean and has no rustiness, oxide coating or greasy dirt); keep the steel needle to be remained in the battery;

c) Observe it for 1h.

6.2.9 Sea water immersion test

Sea water immersion test shall be carried out according to the following procedure.

a) Charge secondary cell according to the method in sub-clause 6.1.3;

b) Immerse secondary cell into 3.5% NaCl solution (mass fraction, simulate sea water composition under normal temperature) for 2h;

c) The water depth shall make secondary cell to be immersed completely.

6.2.10 Temperature cycling test

Temperature cycling test shall be carried out according to the following procedure.

a) Charge secondary cell according to the method in sub-clause 6.1.3;

b) Place secondary cell into temperature chamber. Adjust the temperature of temperature chamber according to Table 1 and Table 2.Repeat it for 5 times;

c) Observe it for 1h.

6.2.11 Low atmospheric pressure test

Low atmospheric pressure test shall be carried out according to the following procedures.

a) Charge secondary cell according to the method in sub-clause 6.1.3;

b) Place secondary cell into low atmospheric pressure chamber. Adjust the pressure of test chamber to 11.6kPa; the temperature is room temperature. Lay aside it for 6h;

c) Observe it for 1h.

6.3 Safety test of battery module

6.3.1 General requirements

The battery module samples shall fulfill the following conditions.

-- The total voltage shall not be lower than 5 times of secondary cell voltage;

-- The rated capacity shall not be lower than 20Ah or be equal to rated capacity of battery used for full-vehicle.

Note. Battery module to be tested can be made up of in-parallel and in-serial actual modules.

All test items shall be carried out with sufficient safety protection measures. If the test objective has additional active protection circuit or apparatus, it shall be removed.

6.3.2 Over-discharging test

Over-discharging test shall be carried out according to the following procedure.

a) Charge battery module according to the method in sub-clause 6.1.4;

b) Discharge battery module at 1I1(A) for 90 min;

c) Observe it for 1h.

6.3.3 Over-charging test

Over-charging test shall be carried out according to the following procedure.

a) Charge battery module according to the method in sub-clause 6.1.4;

b) Charge at constant current of 1I1(A) and terminate when the secondary cell voltage reaches 1.5 times of charge termination voltage specified by manufacturer or the charge duration reaches 1h;

c) Observe it for 1h.

6.3.4 Short-circuit test

Short-circuit test shall be carried out according to the following procedure.

a) Charge battery module according to the method in sub-clause 6.1.4;

b) Short-circuit positive and negative poles of the battery module externally for 10min and the external circuit resistance shall be less than 5mohm;

c) Observe it for 1h.

6.3.5 Dropping test

Dropping test shall be carried out according to the following procedure.

a) Charge battery module according to the method in sub-clause 6.1.4;

b) Drop the secondary cell with positive and negative terminals downward from 1.2m height to cement floor;

c) Observe it for 1h.

6.3.6 Heating test

Heating test shall be carried out according to the following procedure.

a) Charge battery module according to the method in sub-clause 6.1.4;

b) Place battery module in temperature chamber.

— For lithium battery, increase the temperature at 5°C/min rate until it reaches 130°C±2°C and maintain it for 30min. Then stop heating.

— For nickel-metal hydride battery, increase the temperature at 5°C/min rate until it reaches 85°C±2°C and maintain it for 2h. Then stop heating.

c) Observe it for 1h.

6.3.7 Crushing test

Crushing test shall be carried out according to the following procedure.

a) Charge battery module according to the method in sub-clause 6.1.4;

b) Carry out test according to the following conditions.

— Crushing plate form. semi-cylinder with 75mm radius and its length shall be greater than the size of battery to be crushed but exceed by no more than 1m.

— Crushing direction. same as the direction along which the battery has the most possibility to be crushed in terms of battery modules layout on the full vehicle. If the direction with the most possibility to be crushed is not available, apply pressure along the direction perpendicular to the orientation of secondary cells array (as shown in Figure 3);

— Crushing speed.(5±1)mm/s;

— Crushing degree. stop crushing when the deformation of battery module reaches 30% or the crushing force reaches the maximum value between 1000 times of battery module mass and the value listed in Table 2.

— Maintain it for 10min.

c) Observe it for 1h.

6.3.8 Puncturing test

Puncturing test shall be carried out according to the following procedure.

a) Charge battery module according to the method in sub-clause 6.1.4.

b) Penetrate 3 successive secondary cells along the direction perpendicular to battery pole plate (steel needle is remained in batter, as shown in Figure 4) at (25±5)mm/s speed by using high temperature resistance steel needle with diameter of phi6mm~phi10mm (the coning angle of needle point is 45°~60°; the surface of needle is clean and has no rustiness, oxide coating or greasy dirt);

c) Observe it for 1h.

7.1 Inspection classification, test items, requirements and sample quantity

The inspection classification, test items, requirements and sample quantity are shown in

Table 5.

7.2 Type inspection

7.2.1 In case of one of the following situations, type inspection shall be conducted.

— New product is launched into production or old product transfers production;

— Transfer manufacturing plant;

— Resume production after shutdown for over one year;

— Significant change of structure, process or materials.

7.2.2 Judgement rules

If one of test items of type inspection is unqualified, this product is judged as unqualified.