Battery box size

DFord wrote:
Seal the battery box and vent it to the outside to avoid problems.

They will be AGM and I am sealing and venting the boxes.

Seal the battery box and vent it to the outside to avoid problems.

I think I will go 1/2" clearance and insulate the bottom, the boxes will site on the floor of the pickup and be cold in the winter. I am wondering if I should look at venting them with a fan in the summer, I can see the truck getting into the low 100s in the summer.

Some battery cases do swell and contract slightly due to changes in temperature and state of charge. It's very slight but if you had the box too tight it may be a problem. Insulation isn't a bad idea. Heat mats? I don't know about that. I presume they would need to powered by the batteries to provide heat? That negatives probably outweigh the positives on that one. Pardon the battery pun.