I recently replaced the Lithium Ion cells in an ebike battery for one of our empowered riders. But unfortunately after a few months it made its way back to me. It had been working great but recently even though the charger showed it as charged it would not last more than a few minutes before seemingly being flat.
I was curious as the cells were only a few weeks old and should not be draining that fast. Maybe a bad cell was in order?
Anyway I quickly opened it up, but right away I could see the issue..
But after a bit or clean up with Isopropyl alcohol and some new taps welded on its looking and working a lot better
Interestingly this battery case did not have any sealant and relied on a very tight fit of the lid to case. but it was stamped with ( DO NOT GET Wet) so i think it is really only designed for dry weather riding. Most new batteries are much better at keeping the water out. Hopefully this one was saved just in time.