The sole source of your energy is the sun. Controlling your solar-powered items does not have to be difficult and MPPT charge controllers help provide you with the extra boost you need to keep your equipment working efficiently. Maximum power point tracking solar charge controllers are nifty devices that use photovoltaic systems and convert the energy into useable energy for your home and other applications. A 10A controller has a conversion rate of 97 percent and a tracking rate of 99 percent, making this device powerful and almost completely accurate. The battery inside of the controller is a gel battery and is enclosed with a sealed box to protect it. The 40A charge controller quickly recognizes when it is daytime and when it is nighttime. Depending on the type of controller you choose to use, the max current varies and can range in levels from 10A up. There is a vast selection of MPPT charge controllers available for purchase on eBay. Do not risk losing too much solar energy and convert yours with ease today.