Can We Bring POWER TOOL Battery Back from the DEAD?

Cordless power tools are great, especially with Lithium batteries (18V/20V or even more). Until these batteries turn out completely dead, that is. So in this episode we'll take a look at one such battery pack, specifically Ryobi P102 One+ 18V system. We'll see what's inside and try to bring it back to life. Can we resurrect another one?
Unlike previous generations of dumb batteries (e.g. NiCd etc) that slowly deteriorate, and you almost always can charge them to SOME capacity, Lithium batteries have a battery management system (BMS) that can turn off the whole pack suddenly and completely, and may also prevent it from charging ever again. Often this happens when battery hasn't been used in quite a while, and charge fell down below a certain level.
Now, there are good reasons why it is done this way, as there are some dangers in managing deeply discharged Li batteries. However, with some precautions, more often than not these batteries can be brought back into service, sometimes even without significant deterioration in capacity. Even when the pack is beyond salvation as a whole, often it is just a single cell that is an issue, and the rest of the cells can be salvaged and reused. So let's see what we can accomplish in this case!
If you're working with Li batteries, be very careful and make sure you're doing it as safely as you can. There is a mandatory disclaimer that these batteries are potentially dangerous - they can release toxic fumes, ignite or even explode. So don't do it unless you're certain that you can handle scenarios like that. You have been warned.
Don't forget to like and subscribe if you found this useful and would like to see more. Let me know in the comments what you agree/disagree with, what you liked, what you didn't like, if you have any questions, if you know of a better way of doing it, or if there is something that I absolutely should not be doing or have done ;) All constructive feedback is welcome! ;)
Disclaimer:
This video is only for entertainment purposes. Any injury, damage, or loss that may result from improper use of tools, equipment, or from the information in this video is the sole responsibility of the viewer.
00:00 Intro
00:23 Problem: battery pack is completely dead
01:18 Initial test
02:47 Open the battery pack
04:58 What's inside?
05:21 Cells measurement
06:41 I have created a monster! ;)
08:05 Balanced connection, jerry-rigged
10:39 Balance charging attempt
15:25 External charging outcome - oops!
18:31 Test in OEM charger and cordless drill
19:38 Reassemble the pack
20:39 Success - thanks for watching!

[@zoeyzhang9866]

Nice sharing! Any interest in any cooperation? (PCBWay)

[@JustMakeItNow]

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[@zoeyzhang9866]

@@JustMakeItNow I can see you are really good at repairing, if you need, we'd love to sponsor some free PCBs and achieve any collabs together, what do you think?😄