The most basic function of a solar charge/discharge controller is to control the battery voltage and open the circuit. It also stops charging the battery when the voltage reaches a certain level. Older controllers mechanically turned the circuit on and off, stopping or starting the power delivery to the battery.
In most photovoltaic systems, controllers are used to protect the battery from overcharging or over-discharging. Overcharging can vaporize the electrolyte in the battery, causing malfunctions, while over-discharging can lead to premature battery failure. Both overcharging and over-discharging can damage the load. Therefore, the controller is one of the core components of a photovoltaic power generation system and a major part of the balance of system (BOS).
In short, the functions of a solar controller can be divided into:
1. Power regulation function;
2. Communication function: 1. Simple indication function; 2. Protocol communication function such as RS485 Ethernet, wireless, etc. for backend management;
3. Comprehensive protection function: Electrical protection against reverse connection, short circuit, overcurrent, etc.
