A PWM (Pulse Width Modulation) solar charge controller is a device used in off-grid solar systems to manage the flow of power from solar panels to a battery. Its primary function is to:
Prevent the battery from overcharging by regulating the voltage and current coming from the solar panels.
Control the discharge of the battery to prevent it from over-discharging, which helps to prolong the battery's life and improve the overall performance of the system.
Some models also feature a built-in microcontroller, an LCD display to show charging status, and USB ports for charging devices.