This paper presents stability improvement in an on-board battery charger for electric vehicles. The on-board battery charger consist a power factor correction (PFC) circuit and phase shift full-bridge converter. The PFC circuit regulates the DC-link voltage using the voltage and current controller. It also corrects the power factor of an input current. The full-bridge converter has control of the output voltage and current using the DC-link voltage for a battery charging. This paper proposes the design technique using a small signal model of the PFC circuit. The design method of type-three controller for a full-bridge converter is also proposed. A simulation has been performed on the on-board battery charger and their results are presented to verify the validity of the proposed system.