Reviving a 0v lithium ion battery - Page 1
Forum section: electronics / beginners

author: Lycaon
author_rank: Contributor
timestamp: December 27, 2015, 05:50:57 am
content: I've got a box full of salvaged 18650 Li-Ion batteries that test at 0v to 0.1v and I've come across some videos on Youtube of people using a bench power supply to revive them by running them through their preconditioning phase. Essentially, they run 10 mA or so into the battery until the voltage on the power supply goes up to 1.5v or 2v but what they don't specify is what they set the power supply voltage to. The only info I've seen is actually from one of Dave's videos where he mentions in passing that he preconditions at 20% voltage, and that the 60% used by the chip he is looking at was way too high.This video in particular is the one I keep rewatching:Anyone know the proper way to do this? Yes, I know the batteries will likely lose capacity, yes I know it's potentially dangerous. I've got precautions in place

author: Maxlor
author_rank: Frequent Contributor
timestamp: December 27, 2015, 06:35:31 am
content: it doesn't really matter what the voltage is set to on your power supply when you're running it in constant current mode. If you want to charge the batteries up to 2V, maybe set the voltage to 2V then so it stops the current once it reaches those 2V. Be wary though: if the battery voltage recovers on its own to higher than the set voltage, the PSU will be forced to sink current, which most don't support. I don't think you'll damage the PSU in this scenario, but you're in an area outside of the operating conditions of the PSU, so it's essentially undefined how it'll behave.On another note, if you measure 0V from a li-ion, it might just be that its protection circuit has disconnected it from the terminals to prevent a deep discharge. Depending on how that protection circuit is designed, you can recover the battery by simply charging it. Or the protection circuit might act like a fuse and never reconnect the terminals.

author: sleemanj
author_rank: Super Contributor
timestamp: December 27, 2015, 07:15:39 am
content: If they are unprotected cells and really at such low voltage, imo, dump them, even if you recover them to a normal voltage there will be marginal capacity and a much increased risk of unpleasant failure modes. Just not worth the risk.If they are protected cells that have just shut down for undervoltage, no problem.

author: Psi
author_rank: Super Contributor
timestamp: December 27, 2015, 07:37:24 am
content: yepCharge at ~50mA for ~1min then disconnect and measure the cell with a meterIf the voltage is under 2.4V throw the cell away, it's stuffed.If the voltage is above 2.4V put it back on charge until 4.2V.You may want to do a capacity check, if you have the gear, just so you can see how much capacity the cell has vs what its supposed to.

author: AlfBaz
author_rank: Super Contributor
timestamp: December 27, 2015, 08:18:21 am
content: Quote from: blueskull on December 27, 2015, 07:59:34 amor just sand bag them with some left over KFC

author: rck77
author_rank: Newbie
timestamp: February 21, 2021, 06:36:32 pm
content: In case someone is wondering about a battery pack at zero (0) volts, vice a single cell, here's something I found that worked.A 12v Battery Pack was at 0V and wouldn't take a charge.Manufacturer Miady recommended starting up the sleeping BMS with a 9-volt battery across the terminals.I tried this -- it worked! Battery read just over 10V on voltmeter. Immediately connected to charger. Charger recognized battery, began charging.==> I wonder if this same technique (at 3.7v?) would work for a protected cell?(By the way ... my charger says that to enable "spark prevention", it will produce no charging current until it senses at least 3v _from_ the battery.

author: nigelwright7557
author_rank: Frequent Contributor
timestamp: February 22, 2021, 11:53:09 pm
content: Quote from: sleemanj on December 27, 2015, 07:15:39 amI have a battery powered drill i left for a long period.It was dead when I tried to use it.So i put it on charge for a couple of days.When I tried to use it lasted just a few seconds before going dead again.I looked up rejuvenating batteries and it recommend shocking it with 25 volts and supplying over current for a while to get it working again.It didnt work, same old routine worked for a couple of seconds then died.So just bought a new battery.

author: Rerouter
author_rank: Super Contributor
timestamp: February 23, 2021, 01:34:43 am
content: For lithium charge way slower than usual and see if the voltage comes back rather quickly. I usually do 10mA. If the voltage is really slowly climbing its likely already failed partial short and is gone. Which can be confirmed by disconnecting the power supply waiting a few minutes and measuring the voltage.I've brought back dead flat cells a few times. But generally its only been cylindrical cells that came back with most of there capacity. But the esr did take a hit compared to spec.