Great instructions for this 10A Solar charger controller, look on the Amazon item page for some awesome descriptions and instructions too. This is NOT a solar charger it is only for controlling the input and output of the charging of the solar panel. It did seem to have an issue overcharging my battery, not sure what that was about. It charged my solar panel and my light I had connected to it worked great! I love that it also has the 2 USB ports to charge phones or whatever I need. This will be handy when the power goes out. For anything bigger I will need a bigger controller.