Well I finally got a few hours to assemble my 250 A123 cells into modules. Once I got the system down it went pretty quickly. I have the cells assembled into 4 modules. 3 identical ones made of 3p18s that will go behind the seats where the gas tank used to go. The other cells get mounted in a single module of 3p29s that goes up front where the radiator used to be. I went back and forth on how I was assembling the modules but the final design just uses bolts nuts and washers do make it very DIY friendly. If people are interested I can post specific details on the tab connections.
Once I had all the tab connections I needed a way to mount them. I made up some quick end plates with some L brackets so I can connect cables to clamp them together.
For cables I actually had a bunch of left over flight control cables. I simply cut them down and spliced them together. I originally going to use some eye bolts but happened to have these cables.
I also cut up some .008 aluminum into 8" squares to act as cooling fins. I slid them in between every other cell.
This greatly increases the heat transfer from the cells. Individually the cells will be just fine but when you stack them together you decrease the cooling surface area by several orders of magnitude. To solve this aluminum uses the large surface area from the sides and conducts the heat away to the fins. The fins stick out 1" from either end of the cell for convection to wick the heat away. Keeping the cells cool is critical to maintain cell life. This is a fair weather car so I won't be driving it in the cold but this also could be used for heating if you needed.
This pack still needs some adjustment but I wanted to get it made before I left town for a few weeks.
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