What does a charge controller do?
A charge controller, charge regulator or battery regulator limits the rate at which electric current is added to or drawn from electric batteries. It prevents overcharging and may protect against overvoltage, which can reduce battery performance or lifespan, and may pose a safety risk.

What size charge controller do I need?
The most common pv charge controllers come in 12, 24 and 48 volts. Amperage ratings can be between 1-60 amps and voltage ratings from 6-60 volts. So if your solar system’s volts were 12 and your amps were 14, you would need a solar charge controller that had at least 14 amps.

What is PWM charge controller?
Pulse Width Modulation (PWM) is the most effective means to achieve constant voltage battery charging by switching the solar system controller’s power devices. When in PWM regulation, the current from the solar array tapers according to the battery’s condition and recharging needs.

Which is better PWM or MPPT?
PWM is more complex, but does not have any mechanical connections to break. The most recent and best type of solar charge controller is called Maximum Power Point Tracking or MPPT. MPPT controllers are basically able to convert excess voltage into amperage. This has advantages in a couple of different areas