Regarding the problem of battery output power and battery charging improperly in off-grid photovoltaic power generation systems, we analyzed the output characteristics of photovoltaic cells and the charging and discharging characteristics of batteries.

Integrated MPPT controller's charging technology maximum power point tracking, designed a solar charge controller with the same circuit as the synchronous BUCK and used a test prototype. The whole charging process is controlled by using the parallel three-loop PID control method with temperature compensation to realize the intelligent switching of the battery between different charging methods such as constant current, constant voltage, and MPPT. The controller takes care of the charging characteristics of the battery itself on the basis of making full use of solar energy and avoids accidental damage to the battery.