Saving a depleted battery pack

Hey guys

I have a 10S3P li-ion pack which was working great, right up until I left it plugged in while away for a month. The whole pack is now only reading 1.5v on my multimeter :grimacing:

Do i have any chance of saving it?

Thanks James

If the whole pack is reading 1.5, you’re fucked. However, it’s posidble that a parallel group failed and is screwing your reading up. Tear it down and check each parallel group individually, but I wouldn’t get my hopes up.

Make sure it’s not the BMS that died, if it has a bms

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There is no BMS :scream:

Oh so you left it plugged in and turned on?

Technically the cells might be able to recover but I would never use them in anything high discharge again, USB power bank or something only.

Charge each cell at 50ma to 2.7v then 250ma to full, then discharge at 500mah, recharge at 500, discharge at 1A, charge at 1A, if at any point the cell gets hot it’s garbage, if it goes through all that no hotter than the charger itself, it’s ok for low power use. This is a little test procedure I came up with salvaging new old stock laptop cells for my PowerWall, alot of those cells were in the millivolts, but were fine

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Damn, guess it’s time to build a new pack. Maybe they could be used as fireworks?