This paper describes the design of a solar charge controller with microcontroller based soft switching buck converter. Zero current switching technique is used for buck converter design Atmega 16 microcontroller is used for generating the necessary PWM switching signal. The output voltage of the solar panel is reduced to 15 V and it is applied to a charge controller circuit. The overcharge protection and under charge alarm is available in the charge controller circuit. The settings of these protection circuits are adjustable through potentiometers. Win AVR software is used as a compiler for the generation of necessary hex file.12v, 45 Ah Icad acid battery is used for charging purpose. Keywords AVR microcontroller, Charge controller, Lead acid battery, ZCS buck converter, Under over Voltageprotection