In order to solve the battery charge problem under low temperature, liquid cooling battery system was analyzed and studied, and thermal management with heating and preservation was designed. According to the battery low temperature test data and the requirement of battery heating and preservation, battery heating calculation model was proposed on the basis of the theory formula. The performance of battery heating system was studied by the proposed model. Optimization design of the liquid cooling control system was also investigated according to the analysis results. The results show that the liquid cooling battery management system exhibits excellent performance of low temperature heating and preservation.