That picture also shows a sheet metal strap I made to hold the wires on top of the generator box instead of behind the box. Now I can add water to the battery just by sliding it out from under the sofa. I do need to add a latch to the drawer, and am currently investigating several ways to do that.
If you have an AGM battery, all you would need would be the drawer slides and a way to mount a cover onto the battery.













