10 AH sounds pretty optimistic, even assuming an ideal charging regimen, which is a lot of assuming in a vehicle app. A "large deep-cyclebattery like the Optima" would be much more likely to give satisfactory service, given good treatment - Which includes not baking it every day in a vehicle with the windows rolled up... --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .