I have a couple of ruined kobalt batteries just as you do, and must have watched the same video because I also attempted to restore them with no luck.
I have an older battery powered leaf blower which I discovered has some faulty circuitry which causes batteries to excessively discharge over time even when its not being used, to the point that it will 'kill' the pack.
Now I just remove batteries from all tools whenever I'm not using them. Its safer that way anyhow.
Yes, one tool did in both of these batteries. Weirdly it only seems to affect four amp hour batteries. If you put one of those in it, it nukes a brand newly charged battery in about 30 seconds, but a 5 amp hour battery lasts a good 20 minutes. Four amp hour batteries are ruined.
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