I completed a "little" project today that ended up being not quite so little as I had hoped.
Like many class C's, my motorhome has the house battery bank in a tray underneath the entry steps. The overall goal was to replace the (no longer functional) single 12V house battery with a pair of 6V golf cart batteries. The battery tray was clearly designed to be able to hold two batteries, so that should have been pretty simple.
Unfortunately, there's a propane line with an angle iron to protect it that limited the vertical clearance to an inch or so less than the height of a golf cart battery. The angle iron plainly serves no essential structural function.
One solution would be to splice some more tubing in the propane line (adding a couple of joints), form it into an upside-down U shape to clear the batteries, and remove or relocate the angle iron. I didn't really care to do this, though in hindsight it would probably have been quicker and easier.
The other solution was to rebuild/rework the battery tray to extend down a little more, and this is what I have done. I did also trim the angle iron somewhat lengthwise to gain a little additional clearance. (That was a rather laborious process, as many cutting tools would endanger the nearby propane line. I ended up using a jigsaw with a supplemental base to ensure the blade wouldn't go far enough to hit the line.)
Here's the new tray, bolted to the supports from the original one. The original was all welded together; the new one is bolted, as I have neither the tools nor the skills to weld. There are wooden strips (the gray bumper things) along the sides to keep the batteries somewhat centered in the rack; without them, the golf cart batteries can shift such that only about a quarter inch is supported on one end.
To hold the batteries down, I'm using a couple of nylon tie-down straps and buckles, attaching them to D rings with split chain links. The hooks that the straps came with were rather too large and cumbersome for the space available. I build up some wood blocks to guide the straps over the batteries without their running afoul of the filler caps, etc. Here are the wood blocks I made up for the tops of the batteries.
And here everything is all put together. Checking the water of the back battery (in particular) will plainly be inconvenient.