This controller is designed for DC power supply system, small and medium-sized PV modules power system, using a dedicated computer chip to realize the intelligent control, all adopted industrial level chips can be used in harsh environment. The system offers specific indication for the charge, load, sorts of failure and various protections. Various protection such as short-circuit, overload, over charge, particular anti-reversed polarity protection and so on. The controller uses computer chip to sample the parameter of the battery voltage, photovoltaic cell voltage, discharge current, and environment temperature. According to the battery’s character, realized the accurate control of discharge rate, correction of the temperature compensation through special control model calculation.