A solar charge controller regulates thevoltage and current coming from your solar panels which is placed between asolar panel and a battery .It is used to maintain the proper charging voltageon the batteries. As the input voltage from the solar panel rises, the chargecontroller regulates the charge to the batteries preventing any over charging.

       Types of Charge controller:

1.ON OFF

2. PWM

3. MPPT

       The most basic charge controller(ON/OFFtype) simply monitors the battery voltage and opens the circuit, stopping thecharging, when the battery voltage rises to a certain level.

       Among the 3 charge controllers MPPThave highest efficiency but it is costly and need complex circuits andalgorithm.As a beginner hobbyist like me I think PWM charge controller is bestfor us which is treated as the first significant advance in solar batterycharging.