Great point. That got me thinking about redundancy too. If one goes out we should be able to limp along with the fridge on the remaining one until we locate some new ones.
John, I've built a couple and when I posted about them lots of others chimed in. If you search the home builds section you will probably find even more. Any welder can build one easily for your van if you decide to go the frame rail route.
Thanks, Robb had a small aluminum box built but we'd need a bigger one, a second one or a new one in the back. We'll look through the threads here. I talked to Chris today so we may end up with his rear skid plate/battery mount system. Maybe keep the existing house battery box for a great hiding hole or rarely used storage bin since it's not the easiest to get to.