The goal of this research is a proposal of a standard model for vehicle system simulations. Recently, the CO 2 reduction and efficiency improvement of the energy consumption are important subjects in development of the vehicle systems. The new technologies related to vehicle development have continued to increase in complexity. For these reasons, the energy management simulation by the coordinated design of an electric system and vehicle system is required. The electrical behavior of the batteries becomes important to improve the energy management in the vehicle systems. The battery modeling technologies and the application example for vehicle system simulation are reported.