Sally got solar.

Solar panels and controllers are way cheap now, I got a 100w renogy panel, charge controller, mounting brackets and 20 ft of cord all with free shipping from Amazon for less than $200!

Took little time to install, goes straight to the batteries that charge our 12v stuff.   Should be able to keep it charged and the controller will know when it's full or low. 

Fun project, I am going to do a bit more today like install a digital battery meter and maybe drill holes for solar cords....