How to Refurbish a Thinkpad 380ED battery

[IdentityCrisis]

More or less the title. I have never returned a battery, and wanted to know how to disassemble the battery. B/c I don't fe batteries and don't want to do something wrong and poke a battery lmao. Thanks for reading!

[panips]

Strongly recommend that you find an expert or the rebuilding service instead of DIY.

But if you insist...
Nothing special, just like all other kinds of battery packs, you need plastic opening tools like a thin spudger, a lot of Isopropyl Alcohol, and patience.
Usually there is no screws but the case is glued. Apply (as much as you can) IPA and slice through the adhesive with a thin/non-metallic tool, and then gently pry along the seams. The case is most likely held together by plastic clips, try not to break them. Once the case is opened, apply even more IPA and wait until you can remove the battery pack w/ control board which are glued on the case.
It's okay if you break the case, but keep all pieces so you can still tape them together.
!!Be extremely careful when working with the internal components!!
Take pictures before starting your work, from different angles. And, my two cents, use 16650 flat top rechargeable battery instead of 18650 ones.
You should desolder the connections from the positive polar, remove battery one by one until you have all of them disconnected, clean the control board and use a spot welder to rebuild the battery pack from the negative polar. I cannot remember exactly but I don't think you need to do a hot-swap for old batteries earlier than 2000. But it is always good to remove the battery in the right order [1 to 8] but rebuild them in the reverse order [8 to 1]

=================control board============================
|_____________|_____________|_____________|_____________|
[+(1)battery(2)-][+(3)battery(4)-][+(5)battery(6)-][+(7)battery(8)-]

Usually the batteries can be placed perfectly into the case, but since the case is likely broken (or deformed), a smaller battery should be easier to fit. And, don't forget the thermal fuse.
Again, it's dangerous working on Li-Ion battery. Be extremely careful and have yourself well protected. Make sure you know what you are doing and you have all protection ready, like heat proof mat, glasses, or even a foam extinguisher. Otherwise please find a battery rebuilding service to do it...