The most basic function of the solar charge and discharge controller is to control the battery voltage and turn on the circuit, and when the battery voltage rises to a certain level, stop the battery charging. The older version of the controller mechanically completed the opening or closing of the control circuit, stopping or starting the power delivered to the battery.

Controllers are used in most photovoltaic systems to protect batteries from overcharging or overdischarging. Overcharging can vaporize the electrolyte in the battery, causing failure, while overdischarging the battery can cause the battery to fail prematurely. Overcharging and overdischarging may damage the load. Therefore, the controller is one of the core components of the photovoltaic power generation system and the main part of the BOS of the balance system.
1. The use of single-chip microcomputer and special software realizes intelligent control;
2. Accurate discharge control using battery discharge rate characteristic correction. The end-of-discharge voltage is a control point corrected by the discharge rate curve, which eliminates the inaccuracy of simple voltage control over-discharge, and conforms to the inherent characteristics of the battery, that is, different discharge rates have different end-of-life voltages;
3. Fully automatic control such as overcharge, overdischarge, electronic short circuit, overload protection, and unique anti-reverse connection protection; none of the above protections will damage any components or burn insurance;