Solar Charge Controllers

A solar charge controller regulates the amount of charge going into a battery from a solar panel to prevent overcharging, which can damage the battery. 

There are two types of charge controllers:
PWM (pulse width modulation) and MPPT (maximum power point tracking). PWM controllers are cheaper and simpler, but MPPT controllers are more efficient, allowing for up to 30% more power to be generated from the solar panel.