Electric vehicles as a main development direction of future car development, the technology of parking heat storage and heat recovery storage is very important to solve the winter heating and battery cold start. Through using the phase change thermal storage at sphere packing structure, the temperature equalizing and controlling stability of battery power system can be ensured. The research works focus on heat flux characteristics of phase change thermal storage at sphere packing structure, by combining the model of numerical simulation analysis and experimental verification. And, the further analysis focuses on the sphere diameter, multi melting points mixture by uniformity and layered structure. The research shows that the good temperature adaptability and heat flux characteristics in this thermal storage device, by using the way of small diameter and mixing melting points.