There are two battery box harnesses on each battery box as shown below. Like a lot of the other parts I made these out of wood.
They were build around a central shaft that was simply a rectangular piece of hardwood. I started by cutting four of these to the correct dimensions. Next is the larger part at the top. To make this I started with a piece of MDF cut to he correct height and width, and long enough to make all four pieces. I used the router table to cut a groove down the center which will fit over the center shaft.
Next I cut the four pieces to length and marked up where the angles need to be.
Instead of trying to cut the angles I made them on my mini belt sander.
Here is a look at the final piece
Attached to the front of this piece is a little faceted rectangle. I started this with some rectangular pieces of hardwood.
I used the belt sander to create the angled on the edges.
Since this part overlaps the angled section I needed a small wedge to fill that area in.
Here is what these parts look like when assembled.