WalkIntoTheLight
Flashlight Enthusiast
Does anyone know why a "bad" 18650 cell, suffering from very high self-discharge, would suddenly hold onto a charge like it was perfectly healthy?
I have a button-top Samsung 30Q cell (the button top was added after-market) that is only a few months old. I tested it as a good cell when I got it, and it would hold a charge fine. About a month ago, it started suffering from very high self-discharge. It would drop about 0.1v per day, sitting alone on a shelf. I obviously got concerned about it, and figured it must have a small internal short or something like that. When I charged it, it still had its full capacity, the only problem was that it wouldn't hold onto a charge very well.
I decided before getting rid of it, I'd maybe use it for some experiments or something that I wouldn't use a "good" cell for. I started charging it every day, to top it up (while in a metal can for safety). It would always drop to around 4.07v by the next morning. If I left it, it would continue to drop at a steady rate.
Suddenly, I notice that it's no longer dropping voltage, and is holding steady at 4.17v. Huh????
Does anyone know why a cell would go from "good" to "bad", and then back to "good" again?
I have a button-top Samsung 30Q cell (the button top was added after-market) that is only a few months old. I tested it as a good cell when I got it, and it would hold a charge fine. About a month ago, it started suffering from very high self-discharge. It would drop about 0.1v per day, sitting alone on a shelf. I obviously got concerned about it, and figured it must have a small internal short or something like that. When I charged it, it still had its full capacity, the only problem was that it wouldn't hold onto a charge very well.
I decided before getting rid of it, I'd maybe use it for some experiments or something that I wouldn't use a "good" cell for. I started charging it every day, to top it up (while in a metal can for safety). It would always drop to around 4.07v by the next morning. If I left it, it would continue to drop at a steady rate.
Suddenly, I notice that it's no longer dropping voltage, and is holding steady at 4.17v. Huh????
Does anyone know why a cell would go from "good" to "bad", and then back to "good" again?