12 watt Solar Panel (battery maintainer) Mounted on storage shed roof near boat. Took 50' extention cord and cut 18" off female end and attached it to a small solar controller (picture 3) in Lazerette attached to main cranking battery. Attached the long piece to the Solar panel. When connected (pic 2) I have automatic battery maintenance. I leave switch on both so the whole system is maintained. A small switch was added to turn off the battery combiner during solar charging.