While I was on a roll, also got the second battery put in. I had an extra battery case which I removed from the fifth wheel that I traded in on this one.
First I turned the battery case around that came with the fifth wheel and used the existing vent hole that Keystone had already put in. By turning it around I gained more space because the vent hole is off center and this moved the case more towards the right side of the compartment giving me room to install the second case. I require a certain amount of room to the left of the batteries because this is where I store my folding chairs and patio rug. To install the second battery case, I used a key hole saw on my cordless drill. It cut through the metal bottom like butter. Screwed down both cases then added a "Y" (which I also had left over from my previous fifth wheel) and connected the vents together, hooked up the batteries and finished. Here's some pictures:
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Linear Mode
