Trigger method for thermal diffusion test

1. It is recommended to use heating or overcharging as optional methods for thermal diffusion testing. One method can be chosen, but the chosen method should be able to trigger thermal runaway of the individual battery.

2. Trigger object

After standard charging of the battery pack according to clause 6.2.2.1 of GB 43854-2024, select a single cell located near the center of the battery pack or surrounded by other individual cells as the trigger object.

3 Heating trigger

Heating and thermal runaway method: Use a flat or rod-shaped heating device, and cover its surface with ceramic or insulation layer. For block shaped heating devices with the same size as individual cells, this heating device can be used to replace one of the individual cells and directly contact the surface of the triggering object; For thin film heating devices, they should always be attached to the surface of the triggering object, and the heating area of the heating device should not be greater than the surface area of the individual battery cell; Directly contact the heating surface of the heating device with the surface of the individual battery, with the position of the heating device corresponding to the position of the temperature sensor specified in 6.4.4.5; After installation, start the heating device within 24 hours and use its maximum power to heat the trigger object; The power requirements for the heating device are shown in Table 2. If necessary, the heating power can be increased to ensure that the triggering object experiences thermal runaway; Stop heating when the triggering object experiences thermal runaway.