In this paper, a comprehensive and detail design procedure for the low cost and fast solar charger with the rooftop PV array of the vehicle is presented. A simplified maximum power point tracking technique is adopted to take advantages of the simpler structure of the circuit and the shorter charge time than those of the conventional solar charger. In the small-signal modeling of the converter, linearized equivalent circuit models of the PV array and the lead–acid battery are included for the accurate charge control all over the operating range. An experimental prototype is implemented by using a buck converter with a digital signal processor as a controller and tested by using the Elgar TerraSAS solar array simulator to verify the feasibility and validity of the system and its control algorithm.