I decided to mount the two new batteries under the floor near the spare tire in the back. They were just going to take up too much room inside the van and too much of a pain to vent. The next step was trying to figure out how to mount them under the van. I found some metal pieces in my neighbors shed that she was kind of enough to donate to the cause. I get a lot of joy out of cobbling together found parts to make something useful. I hope to get this electrical wrapped up in a week or so.