A solar charge controller is simply a device used to regulate the way solar panels applyelectrical charge to your batteries. It is the charge controller that regulatesthe charging of the batteries. It detects when to allow the maximum availablecharge that the solar panels can produce to be applied to the batteriesand it also detects when the battery is fully charged and cuts off the chargesupplied by the solar panels.

       Some solar regulator have some other functions like providing an outputconnection where you can attach your D.C (direct current) loads. Thismeans that you can connect lights and other devices that use DC directly viathe charge controller to the solar panels without using an inverter. Some alsoprovide USB outlets to connect your USB devices directly to your solar panel.These are secondary functions of the solar charge controller though.