Thermoelectric cooler (TEC) can utilize electric energy to realize heat energy transfer directly. With the PID (proportional-integral-derivative)temperature controller, the cold end of the thermoelectric cooler can achieve precise temperature control and meet the needs of battery thermal management. Previous studies primarily emphasize structural optimizations in hybrid battery thermal systems. Few of them have reported the quantitative influence of various factors. This work established a thermoelectric device-battery pack experimental platform. Fluent software was used to establish a battery thermal management model based on thermoelectric cooling, and the accuracy of the model was experimentally verified. A simulation study was carried out to systematically investigate the effects of initial temperatures, cold plate surface temperature, and discharge rate on the thermal characteristics of the battery pack. Within the simulated operating range, increasing the initial temperature of the battery increased the maximum temperature (Tmax) and maximum temperature difference (ΔTmax) during the discharge process. However, the initial temperature of the battery had little effect on the Tmax and ΔTmax at the end of discharge, which were 28.5~28.6 and 3.0℃, respectively. Therefore, the battery could be cooled down first when working in a high-temperature environment. Lowering the surface temperature of the cold plate will reduce the Tmax and increase the ΔTmax during battery discharge. When the surface temperature of the cold plate was 5℃, the Tmax during battery discharge was 17.5℃ and the ΔTmax was 5.4℃. Therefore, the surface temperature of the cold plate should not be too low. Both battery non-uniformity and maximum surface temperature increased with the discharge rate. Sensitivity analysis showed that the highest temperature at the end of battery discharge was sensitive to the cold plate temperature, with an average sensitivity of 0.527. Adjusting cold plate surface temperatures effectively enhanced heat efficiency dissipation in thermoelectric cooling battery management system.