Another idea is to keep all your present underfloor storage for storing things (and you will have plenty of things to store!), and make separate underfloor pull-out trays for batteries. The advantage is that the batteries will be easily vented, being open to the road below (useful if any acid decides to spill out), and some simple vents in the top of their access door will take care of any hydrogen gas. I made my trays using 1-1/8" OD bearings running on 1" square tubing, and they're strong enough that when fully extended I can not only stand on their ends but even jump on them. I think it's important to be able to easily access all the batteries to water them and check their SG every fortnight or so. A friend of mine in the RV yard where I keep my bus has a high-dollar RV, but its battery compartment has no pull-out trays - he has twice in the last few years had to replace all his expensive batteries because one in the back, completely inaccessible, failed and killed all the others. If he had a way to easily check them he could have saved a lot of money and aggravation. I find it incomprehensible that a half-million-dollar RV did not have pull-out battery trays as standard!
If you put your battery trays next to the underfloor storage bay, you can keep the cables as short as possible, but still keep the expensive electronics such as inverters or charge controllers away from corrosive battery fumes. Yes, it's more work to do it this way, but we're only doing this once so why not do it so you don't have the "I wish I'd . . ." remorse later. After all, we're converting buses because we can make them functionally better than flashy mega-dollar RVs!
John
