Throughout daylight hours, the Solar 40 charges your battery. When needed the stored battery power will be used. 

 

How much will I need? It all depends on your lifestyle, but first install a 40W MASTER Panel and see how you manage. 

 

If you need more generating capacity, simply connect a 40W ADD-ON Panel. The system can be extended to a total of four panels - a capacity of 160 Watts.