Abstract: To enhance the adaptability of phase change materials （PCMs） to heating power and ambient temperature, a novel strategy is proposed to expand the temperature control range by using binary double-peak PCMs with two heat absorption peaks. The influence of thermal conductivity on the temperature control performance is investigated through thermal simulation of the battery thermal management process. Concurrently, the temperature control performance of the lauric acid-stearic acid binary mixture （LA30-SA70） is evaluated under six ambient temperatures and three heating power levels. It is indicated by the results that the temperature control performance is progressively enhanced with increasing thermal conductivity, but the optimization effect gradually stabilizes. A critical point for the battery pack temperature control optimization is reached when the thermal conductivity is 1.5 W/（m·K）. Compared with conventional single-peak PCMs lauric and stearic acids, LA30-SA70 demonstrates superior performance across six ambient temperatures, with a maximum temperature difference of less than 1.8 K and excellent ambient temperature adaptability. Under varying heating power conditions, the battery pack temperature is effectively regulated within an optimal range at a low heating power of 10000 W/m³. Furthermore, under the combined conditions of an extreme ambient temperature （323.15 K） and an extreme heating power （100000 W/m³）, the battery temperature is successfully constrained within the normal operating range （< 333.15 K）, thereby confirming outstanding heating power adaptability.