A solar charge controller is an electronic device used in off-grid and hybrid off-grid applications to regulate current and voltage input from PV arrays to batteries and electrical loads (lights, fans, monitors, surveillance cameras, telecom and process control equipment, etc.). The controller safely charges and maintains batteries at a high state of charge without overcharging. A good solar charge controller can extend battery life, whereas a poor quality charge controller can cause battery failure and which causes the entire off-grid system to shut down. Solar charge controllers are also commonly called solar charge regulators.
A solar charge controller is available in two different technologies, PWM and MPPT.
An MPPT solar charge controller stands for “Maximum Power Point Tracking”. MPPT can monitor the voltage and current of the solar panel in real time, and track the maximum power so that the system can charge the battery at the maximum power all the time.