That's handy. What latitude did you figure that out for?VidPro said:...you need ABOUT 15W to recharge a 7A 12V gell cell type battery, without tracking the sun, you can get away with as little as 3W to just top it off, and get it charged in a week, and a 5W to get it charged in 2 days, and a 10W to keep it going, if you dont run it out totally...