This study aims to find a new technology of bi-directional converter for battery electric power storage device. The generally DAB(Dual Active Bridge) Converter is connected with switch(8), transformer(1) and inductance(1). It can constitute a large-capacity/low-voltage battery with ten times higher step-up/step-down ratio and soft-switching function. To obtain Step-up/step-down ratio 10 times higher and Soft-switching function to achieve a high efficiency, the toplogy is able to compose the high capacity/low voltage battery. It operates efficiently the proposed DAB converter better than the DAB converter from coupling inductance. The toplogy is operated during charge buck converter operation and during discharge boost converter operation. This experiment can be applied to the study of the system for boosting the voltage of a future ESS, BESS the UPS. It toplogy can use operating Voltage Source Control and Current Source Control. This paper proves to use computer simulation that is PSIM and is excellent control system.