I got this battery box from bestconverter.
I modified the door by removing the piano hange and replacing with channel and drawlatches so I can access the box without interfering with the propane tanks.
It holds two type 31 AGM's so we've got considerable 12v
staying power. Since I am currently towing with a F350 DRW I'm carrying the spare tire in the back of the truck instead of the tire bracket that was in this location. Also, I don't need a weight distribution setup. If I did I would add spacers to allow enough room under the box for the frame brackets.