Abstract— The photovoltaic (PV) stand-alone system requires a battery charger for energy storage. This paper presents the modelling and control design of the PV charger system using Buck-Boost converter. The voltage command is determined by both the PV module maximum power point tracking (MPPT) control loop and the battery charging loop. Here the controller is designed so as to balance the power flow from PV module to the battery and the load such that the PV power is utilized effectively and the battery charged with three charging stages. This paper discusses the design and simulation of buck-boost converter with battery charge controller and MPPT controller using MATLAB.