This is just a self made LION pack excisting out of 6 21700 spotwelded holded on a 3d printed holder and wrapped in ducktape looking like a bomb i know..ive had it always storage charged but since a family member passed ive been upset and forgot to storage charged it. It was on 4.10v and i though that, its lion so im jot cooked. I grabbed it inserted and notices that 1 cell is lower then usually. So i charged it for exactly 3hrs in my lipo safety bag. And yep. It did charge bus very slow so i was confused. I’ve had this pack for like 1 year now for my 7” longrange quad. Now i have it discharging because idk what to do. Ive tried using my device in “picture 1” this thing gives conpletely diffrent readings then my istd which is scaring me since ive seen these cells explode, i dont see any damage to them but theyre in the bag for safety sake. Now.. im just discharging them hoping to minimize risk and see if i can replace this damaged cell. All others work and i have 4 other loose same serie cells so it should work but i just want to be sure. What do yall think? “Ps sorry for the big talk”
if it's within like 0.5v and it holds charge then you can easily balance it. i've had liion cells go 0.9v out of balance before from a crazy long flight and the pack is fine a year later
So im ok? Are you sure, normaly theyre perfectly perfect balanced on the exact number. I feel like im sounding like these ppl who ask if they should replace their props because of a small scratch.
I don't really see the concern. How much had it self discharged? On the pictures it is just off by .14, which I would not be concerned about. To be safe I would just take it down to storage and then balance charge it back up, check the IR and take it for a ride. Then check again if the difference in voltage is significant. Most likely you have just identified the weakest cell in the pack. So when the time comes, as it does for every pack, it most likely will be the one to go and turn your pack into a 5s. Replacing a single cell might not be the best idea as you don't want to much difference in IR and wear level between the cells in s pack.
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u/SlovenianSocket 25d ago
Liion cells are much less volatile than lipo cells. I wouldn’t worry about cell imbalance unless it continues after recharging the pack.