Now that I have an enclosure that I can work with, I need to put the actual battery together.

I have a spotwelder that I built a few years ago which thankfully still works. I already made a few tests during shaver-repair and plan on spot-welding the new pack together over the weekend if I find the time. All cells are still very well balanced (down to 0.01V) and can be welded together without any additional balancing action on my part. I'll double check each cell again, though, just to be safe. LiFePo4 won't burst into flames but hot wires are also not needed here.

Once I have the cells welded and the pack somehow stabilized, I'll try and solder the power cables to the nickel strips and run the wires through the hole in the top cover straight to the screw terminal. I did it this way so that the power doesn't go through the bolt but instead connects directly to the leads to the motorcycle. I hope this will generate less heat, stressing the PLA less. Honestly, this is going to be an issue. I'm aware of it but I don't like it either. But it was the material I had available at the time of printing.

After (maybe before) the power cables are attached, I'll solder the 4S balancer into place. It says it doesn't like high capacity packs but since it's probably analogue it will just take longer to balance. And since I don't draw much continuous current from the pack and also have the pack sitting for long periods of the time it will (hopefully) eventually balance.

Then, I'll run the ground wire to the pack and the positive lead from the pack to the battery shut-off switch and from there to the positive lead of the bike. All this, in theory, should be pretty straight forward. There will be a bit of improvisation and probably incorrect terminals but that's an issue for a later day.