Actual protip: occasionally, lithium ion batteries appear to completely fail. Sometimes that's not because they've failed, but just because they dropped below a certain arbitrary voltage level and the controller isn't allowing the cells to charge. In this case, you can apply the correct voltage at a very low current to raise the voltage above that threshold and like magic the battery comes back to life.
Happened to me 2 times this week. First with a drill battery, second with the battery out of a rugged Samsung tablet. Both were perfectly fine and normal once I returned the cells to their minimum voltage.
Now, be careful: it's important to limit current and voltage because if there's something wrong you don't want your cell to blow up in your hands!
Happened to me 2 times this week. First with a drill battery, second with the battery out of a rugged Samsung tablet. Both were perfectly fine and normal once I returned the cells to their minimum voltage.
Now, be careful: it's important to limit current and voltage because if there's something wrong you don't want your cell to blow up in your hands!