The demand for battery fed electrical vehicle (BFEV) is expected to ascend with the rapid depletion of the earth's petroleum resources. But the range of BFEV is still limited due to the limitation in energy conversion efficiency, energy recovery during braking operation and fast transient operation. So, the analysis and improvement of energy conversion system for BFEVs is strongly recommended. This paper presents a highly efficient electrical circuit for BFEVs with the combination of a PI controlled bi-directional DC-DC converter and a Cuk converter. First, the PI controlled isolated DC-DC bi-directional converter is designed to provide desired battery voltage for dc motor control and to run the flow of power under both steady-state and transient conditions. A boost converter is designed by using one IGBT and one MOSFET in parallel to condense the conduction loss and to guarantee a high output voltage. A comparative performance analysis between a Cuk and a boost converter technique for BFEVs is also presented. An equivalent MATLAB/Simulink simulation model of the both system is developed to investigate the performance of both electrical circuits at different operating conditions. The Cuk converter technique exhibits higher efficiency and better performance as compared to the proposed boost converter technique.