Ah I see. Even when protected from UV? I did put a piece of foam under the batteries to help with stretch and Insulate it a bit.Because the webbing tends to stretch and deteriorate over time. Then it comes loose at the worst possible time.
Ok, I was trying to stay away from a metal strap... I guess I might have to.Ratchet straps are just about one step above bungie cords. A typical set of J-bolts and a bracket across the top is the best and most common way to secure batteries. I would also consider a tray of some sort that will keep them from shifting around.
They are sealed agm's.If those batteries are flooded lead acid, you will want a tray under them in case the electrolyte solution boils out of the vents during charging. I also concur with the switch to steel straps and J bolts.
Totally agree on planning for worst case. I just didn't even see that as an issue. One of the reasons I post for ideas like this.Unsecured batteries are never a good idea and storage batteries like those tend to be ignored for long periods of time so it's possible they could come loose and you may not even know there was a problem until something went very wrong. Honestly, if it were my rig, those would be stored outside the box, a firewall separating them from the living area, have a tray that held each battery securely without letting them touch or rub against each other and would be securely bolted down so they can't shift, move or come loose in an accident. They may be sealed now when they are new but there is no telling what may happen in the future and a busted could cause all sorts of problems and an accident may be bad but it could get much worse if a battery gets loose and starts a fire. Worst case scenario, but sometimes you have to take that into consideration when you are building something you are going to be away from home in and sleep inside. I'm sure Lance never thought their RV would burn to the ground from having R/C batteries rupture while charging but bad things do happen. Not saying your batteries are in any way similar to R/C batteries, just that things can get unpredictable in general. Just my .02