Revive dead 18650 batteries (29) from severely damaged ebike battery pack

This pack is damaged by water. All of them are under 1 Volt which chargers refuse to charge. There are 29 dead cells. Some of them are heavily corroded. Can they still be revived and put back into service? Let's find out.

[rickdff]

Doood...I just fixed a couple of 18650s I had lying around and a Makita tool battery using you're technique. The magnet trick on the battery terminals to hold the leads is pure money. Thanks so much!

[Arubapower]

One of the best videos for 18650 batteries

[marbesky]

I have been doing this paralel charging sorcery since 2004 with many lipo cells and 18650s 95% worked perfect

[powerthoughtsontools]

I would have to review this video; but it is really commendable that you go through that whole process to truly determine a cell's potential for future use. Well done man! Would love to meet you!

[SailnowFun]

Just want to add my kudos for this procedure. I had a completely dead Iridium satellite battery that wouldn't charge. I didn't have a way to bridge the one that does work without a lot of hassle, so I used my volt meter's 9v output connection to do the same thing... 30 seconds. Worked perfectly, and the battery now accepts the charge.

[scltechhelp]

You are my Bob Ross of Batteries and narration! Awesome videos!

[aljsegovia]

Good explanation. I use to pre-charge those low-voltage cells with an old cell phone charger. It provides 5 vols, but the current is limited to 500 mA. 20 or 30 seconds are enough to achieve 2, 5 or 3, 0 volts. Voltmeter connected in parallel, just in case.

[bellapool]

listening to you puts me in the mood for some Pho & Banh mi

[Docbill]

I tried this on an mp3 player that would not power on - opened case, tested battery at about 2V (rated at 3.7), applied 4.5V for about 30sec at which point battery tested at 2.8V, re-connected mp3 to charger for 30min, reset mp3 which powered on, reconnected to charger and mp3 is accepting charge. Thank you so much for your help!

[luckylarz]

Good video I appreciate what you do and the Info you share! Thank you for the work you put in.👍

[SaitoGray]

I've been doing it with a cut-off USB cable, works fine too !
Thanks a lot, you saved my battery salvaged from dead laptops !

[mochapella]

thank you so much for your clear and methodical demonstration. much appreciated!

[Neilhuny]

I've looked at quite a few of these battery related vids and this is much the best imo

[Supercon]

Thank you very much
I have that same OPUS charger and was having a problem with some cells not charging because of their low voltage
This is exactly what I needed!

[JanErik]

Nice recovery of those cells. Clearly show they are not trash just cause they were drained completely.
I haven't tried with cells lower then 1V on the Opus, but i have tried with several cells in the 1, 12-1, 45V range, and they did all charge up properly to 4.2V, and didn't stop at 1.5V (I'm curious what causes the charger to stop at 1.5V only with some of these low volt cells though?).
An important thing to keep in mind is that while over-discharged li-ion batteries can safely be recovered, they are not all fully stable until ~3V from what i understand.
Below the stable voltage the charge current should be limited to around ~0.1C (ref. Sanyo ur18650f datasheet, as an example), so to be on the safe side i would maybe recommend to use a resistor to limit the current when paralleling cells to boost the voltage up to a level where the charger accepts it.

[amberyooper]

I'm glad I found this video! This gives me some really useful information for trying to salvage cells from battery packs that won't charge. I think that half the problem with battery packs that won't charge is due to failure of the charge controller in the battery pack. I could be wrong about that, but it would explain sudden failures of battery packs.

[Anonymous-itjw]

Thanks for this video. I have 3 chargers very similar to the ones you used, so I can test and bump up the voltage on my old batteries exactly as you did. I particularly liked your home-made box for safely removing battery corrosion using a Dremel-type rotary tool.

[exploitingtheirpower]

Your videos are so awesome very informative and entertaining. I was searching how to brake down e bike packs and came across your video I’m glade I did now I can start restoring batteries

[pointedspider]

i like to use a USB charger with a stripped USB cable to revive my batteries. Apply 5 volts for 10-15 seconds and it will raise battery voltage from 0.5 to 2.8-3 volts quick. i have some 18650s that i revived over 10 years ago by doing this and they are some of my strongest, longest lasting cells i have.

[anuruddhalogin]

Learned a lot from this video !
Thanks from Sri Lanka.