Abstract: To investigate the thermal characteristics of NCM ternary lithium batteries under FSEC event conditions and the feasibility of their application in FSEC events.The relationship between the internal resistance and the SOC of the battery and the temperature change of the battery when discharged under specified operating conditions were first investigated experimentally.Then based on the relationship between the internal resistance of the battery and the SOC, a model of the thermal effect of the battery was developed, using this model to calculate the temperature rise and temperature difference variation of the battery.A comparative analysis of the experiments and simulations leads to the following conclusions： ① the temperature rise and temperature difference of the studied battery are positively correlated with the discharge time; ② the battery can work normally under the set normal discharge conditions; ③ the established thermal effect model is reasonable.Finally, by adding a study of the thermal characteristics of the battery when discharged under extreme operating conditions, the above conclusions are verified to be more accurate.This study will provide the appropriate basis for the design of subsequent battery thermal management systems for vehicles.