Take a peek at my pics on Webshots.
I installed the battery in a sealed plastic and vented box under the seat along with the diaphram pump. I also store my jacks, hose and extension cable in there. That leaves all the other other compartments free for storage.
The battery is charged from the truck when we are are on the road and charged by a solar
trickle charger in the back window when we are parked. It has worked very well for us.
As far a having a steel battery box, avoid them like the plague. Use either plastic or stainless steel.