Solar panels produce an electric current through the photoelectric effect of light. Due to the properties andlimitations of materials and light, the generated current is a curve with volatility.If the generated current is directly charged into the battery or directlysupplies power to the load, it is easy to cause damage to the battery and load,which seriously reduces their service life. Therefore, we must first send thecurrent into the pwm solar charge controller, using a series of special chip circuits to digitally adjust it, using three-stage charging, to ensure the safe operation of the battery life. When supplying power to the load, the current ofthe battery is also let to flow into the solar controller first, after itsadjustment, and then the current into the load. The purpose of this:

       1,It stabilizes the discharge current

       2, It ensures the battery which is notdischarged

       3,It monitors and protects load and battery