Buck and Boost modes, which working alternately. Hence, it has two output directions: Buck mode for decreasing the voltage and Boost mode for increasing the voltage at certain levels. In this work, we applied a non-isolated topology of the Bidirectional DC/DC converter for electric vehicle, that is mini all-terrain vehicle (ATV). We set a Buck mode to charge the Supercapacitor when the battery current and the Supercapacitor voltage are lower than considered level. Whereas the Boost mode was used to discharge as well as buffer the mini ATV when the battery current and the Supercapacitor voltage are higher than considered level. The discussion of Buck mode has been presented in previous work, so in this work, we focus on the Boost mode analysis only. This mode is set to increase the Supercapacitor's voltage. The Supercapacitor with 25 VDC/8 Farad was used as the secondary main power inside the 22.2 VDC / 5000 mAh LiPo battery of the mini ATV motor. The mini ATV requires 36 VDC to work. Thus, it must be boosted first from 22.2 to 36 VDC using an external Boost converter. Moreover, it must be maintained at 36 VDC. Based on the requirement, we first design the bidirectional DC/DC converter involving the mathematical calculation and then simulate it into LTSpice®. The Printed-Circuit Board is then lay-outed and mounted. Later, we connected the designed system to mini ATV motor and tested the performance as well. According to the laboratory test, the Bidirectional DC/DC converter can increase (Boost) the voltage of the Supercapacitor from a certain level to 36 VDC. On the other hand, it can maintain 36 VDC. The central control in this system uses the STM32F4 Microcontroller, while the battery monitoring system employs the STMStudio.