Off-grid solar power supply system is mainly used for application with relatively-smallpower consumption, and the areas have no grid network coverage, or grid power is inserious unstable or outage condition. It’s composed of solar panels, controller, inverter,battery bank, solar panel mounting racks, and other accessories required for acomplete system. The solar panels generate electricity at daytime and charge thebattery bank through the controller. The battery bank gives a stable power output to theinverter which converts DC to AC to power loads, and provides power backup in rainyor cloudy days. The controller gives an intelligent control of whole system process andprovides various protections. The solar-grid hybrid system provides grid power bypassin case of battery power shortage when sunshine is not enough.