Please help! Replacing batteries

Hi, I bought 2 Powershift Inboard Batteries but they were dead.
So I have two new unworking batteries… I opened the case and saw they use LG H4 cells.
Do you think it could be possible just to replace the LG H4 unworking cell with healthy LG H4 using the same BMS? Can I use LG HG2 or Samsung 25R instead? I don’t have the BMS software, so I would just take off the old cells and weld the new ones. Please help me, thank you!!!

It’s a bit of a risk in not knowing if somebody tried to run it with the dead cell or how many times they charged through it - other cells could be damaged - but in the grand scheme of things, the only damage should be total capacity down by some percentage. Not knowing why the cell died always sucks…

If you want to replace it, use the same model of cell. Do not mix. Mixing will work, but it’s dangerous.

Ok, thank you S5300!!! All cells are dead, so I will replace all of them.
The question is, can I take off the unworking LG HE4 cells (2500mAh) and weld new LG HG2s (3000mAh)? I would be using the same original BMS and electronic. Do I have to do something else besides taking off LGH4 and connecting new HG2 cells?

Thank you!!!

I could not recommend using LG HG2’s in one p-group of a battery with the rest of the p-groups being composed of LG HE4’s. Internal resistances could differ and cause issues.

However, truthfully, I’m not sure and I’m making an educated guess.

I recommend you buy new LG HE4’s and weld them in. Hopefully somebody else can chime in.

It should be less than $20 shipped for new cells…

Thank you s5300!!!

Were you able to get this working? I would be interested in paying you to complete one for me. I have several Powershift packs that no longer work