Hi Jane & Tom, I'm coming at the electrical supply problem from a different direction than you are. My "problem", which really isn't much of a problem, is that I want to run my GPS continually, and also want to run my SONY CD player for a little Vivaldi or Mozart when I'm sailing. What I am doing is installing an electrical panel with cigarette lighter socket in the starboard side of the porta-potti area. This panel has a voltmeter so I can monitor the status of the battery. (WEST Catalog item) I intend to buy a motorcycle battery. They are about 3 1/2 inches wide x 6 to 7 inches long x 7 inches high - depending on model and capacity. Then I'll build a fiberglass battery box to fit in the bow compartment, along the aft wall, just under the lid. With this combination, I will have adequate 12 volt power for my GPS / CD player, and when the battery voltage drops it will be easy enough to remove the battery (weight maybe 15 lbs) and take it home to recharge it. This should work for you as well, and give you a the possibility of running naviagation lights when needed. Connie M15 #400 LEPPO