Solar Charge Controller is an electronic device that manages the power going into the battery bank from the solar array. It ensures that the deep cycle batteries are not overcharged during the day and that the power doesn’t run back to the solar panels overnight and drain the batteries. Some charge controllers are available with additional capabilities, like lighting and load control, but managing the power is its primary job.
A solar charge controller is available in two different technologies, PWM and MPPT. An MPPT charge controller is more expensive and highly efficient than a PWM charge controller, and it is often worth it to pay the extra money.