I'm going to try using NiMH batteries in the test system. They are plug compatible with the existing Gel Cell batteries but can be packed into a smaller space. Making this change would restore the volume of the wire storage area. If they work well, we could wait until the gel cells need to be replaced before updating them on the club system or we could swap them out early and use the gel cells as parallel power boosters/chargers. Even if we don't go with them, I think it is worth testing them.