In this study, the step up DC-DC converter that works in push-pull connection has been taken up. The voltage-drops that occured since input voltage was low, have been minimized. The IRF 1310N mosfet which had minimum conduction resistance was preferred when we were selecting semiconductor elements used for voltage-drop minimization. As the current value switched in converter was high, the current capacity was increased by connecting the mosfets as parallel. At the same time the voltage-drop occured on semiconductor element, was minimized.