How to achieve up to spec battery compression?

Brucey said:

You can use poron 4701 foam sheets and compress it ~25% from original thickness to achieve the target psi.

Click to expand...

Like this guy.

I used Poron 4701-50-15250 from McMaster-Carr (SKU 86375K234). Then I tested the compression. Adding extra layers of foam is the same as putting springs in series, so you don't want or need a layer between each cell. One 1/4" sheet per four cells is about right.

See starting at this post in The big ol' compression thread

Note that my side panels are measured and cut with that specific amount of compression in mind. In other words, I have to use bar clamps to put the second end cap on so that the screws will fit into the holes in the end cap. No springs, just a hard case. Yes, it should be 10mm end caps, but I needed every inch I could get. Each 16S battery is made from two 8S compressed boxes next to each other. This photo was taken before the BMSs were added on the layer above the batteries. You can see the Poron foam between the end cells and the white end caps. It is the same on the other ends.

A closer look at the frames. The edges of the cells have Kapton tape on them, and the cells have FR4 sheet between them. The Poron foam is visible between the last cell and the end cap.