BATTERY LAYOUT SCHEMATIC

This my Battery Pack, 2 levels, one on top of another. The lower level is in the original aluminum container that came with the truck (old US Electricar AC conversion). The upper level is a metal box I've constructed that will roll back and forth on rails and 'V' groove stud rollers when access is needed. The normal bed is being removed and replaced with a custom made one. I'll also but some aerodynamic faring on the back.

The upper level has a 'cold plate' incorporated into it, as suggested by Lee Hart. It is a sandwich of .080" aluminum plate, some 1/4" copper tube that snakes back in forth in a reverse spiral pattern and a 1/2" layer of soft foam. The weight of the batteries will be distributed over the area of the .080" plate and compress the 1/4" tube into the soft foam. The in/out of the tubes will be connected to the existing radiator system.

This is a pic of the tubes tied down to a piece of cardboard so I could bend them to the pattern. The reverse spiral is neat because the in/out are located together. The battery box is about 46" long x 40" wide x 15" high. The walls and bottom have 1.5" of extruded styrene insulation and there is white Coroplast as a protective membrane/cover on the outside.