The solar controller is a device used to control the photovoltaic panel to charge the battery and provide load control voltage for voltage sensitive equipment. It regulates and controls the charging and discharging conditions of the battery, and controls the power output of the solar cell components and the battery to the load according to the power demand of the load. It is the core control part of the entire photovoltaic power supply system. It is specially designed for the power supply system of communication or monitoring equipment in remote areas. The controller's charge control and load control voltages are fully adjustable and can display battery voltage, load voltage, solar array voltage, charge current and load current.

Almost all solar power generation systems powered by batteries require a solar controller. The role of the solar charge and discharge controller is to regulate the power delivered from the solar panel to the battery. Battery overcharging, at least significantly reduces battery life, from damaging the battery at worst to the point where it cannot be used normally.