About Charge Controller
A solar charge controller 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. How they perform in a system is very different from each other.
What is MPPT & PWM?
The MPPT (Maximum Power Point Tracking) solar controller is the shining star of today's solar systems. These controllers actually detect the optimum operating voltage and amperage of the solar panel array and match that with the battery bank.
A PWM (Pulse Width Modulated) solar charge controller is the traditional style. They are robust, inexpensive and widely used in solar panel applications. PWM shunt controllers are used less often and mostly in applications where electrical interference is an issue.