NESE Battery Build Questions

I’m attempting to build a 12s3p pack using Molicel P42a and the NESE system.

My plan was to make two 6s3p modules and then connect them using bus bars. I built one 6s3p module so far:

I have a few questions:

I noticed after inserting all the cells that the longer tab strips (the ones that are connecting two parallel groups in series) seem to be angled up slightly. I wasn’t able to push them down, even after applying a lot of force. This doesn’t seem to be interfering with the lid of the module, but is this going to cause issues with the bumps on the tab strips not being centered on the cells?

Also, I noticed that on one of the plastic walls that separates two parallel groups, the shrink wrap from one of the cells is sitting on top of the wall, as if it has somehow gotten pulled out away from the cell. Is this normal, or am I damaging the shrink wrap somehow?


This is my first time building a lithium pack, so I appreciate any input. Thanks!

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The divider makes spacing off so the tab does not sit well. It will be off center but there is some allowance and should not cause any issues.
Dont know about the shrink wrap. I would inspect the cell.
Personally i would remove that separator and use some fishpaper beween S groups instead so everything lines up perfectly. I would also print at 101% for these cells as they are larger

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Thank you for your input. Is there a good procedure to safely remove the cells now that all of them are in the pack? I’d imagine it gets easier once one cell is removed, but I can’t seem to grip any of the cells tightly enough to pull them out now.

I take them out with the orange lego brick removal tool.

I put a small strip of fish-paper between my p-groups just enough to protect against possible side wall shorts. So far so good.

I usually bang them on my palm. Better be with leather glove or something :slight_smile: