At low temperature, the performance of battery declines significantly. Thus Battery Thermal Management System (BTMS) for heating and maintaining its temperature in proper range is crucial when the batteries of electric vehicle operate in cold climate. The objective of this study is to investigate the effects of heating parameters on the heating performance of BTMS based on heat/cold plate method. A 3D model of 6 battery cells and heat/cold plate was built in COMSOL. The numerical study considered three effects under the cold climate of −20 °C, which are the discharge rate of battery, inlet mass flow rate of heating medium and inlet temperature. According to the results, the batteries cannot be heated to its proper operating temperature range only by vaChongqingrying the discharge rates of battery. In addition, the discharge rates also have a negligible effect on the temperature raising compare with external heating source. With external heating source, higher mass flow rate can achieve a better heating performance, but it is limited when the mass flow rate exceeds 0.065 kg/s, which increase of the heating medium inlet temperature can more quickly heat up the batteries, but it may lead to the maximum temperature of batteries exceeds 40 °C. Among the calculated temperatures, the inlet temperature around 45 °C can be a reasonable temperature for the battery heating of BTMS based on heat/cold plate.