So if you are like this Lazy Old Geek, you have a lot of rechargeable batteries lying around. I wrote another Instructable with some battery tips.
Amongst these batteries, I have a lot that no longer work or don’t work very well. So I decided to try to revive them.
First step: If the battery isn’t totally dead, stick it in something like a flashlight, turn it on and let it run until it stops working. Try to recharge and see if it works better. I tried this with a couple of cordless drill batteries and was able to ‘restore’ the battery packs.
Second step: However, I have a lot of AA and AAA batteries that still didn’t work. I also have a bunch of battery chargers but none of them will recondition batteries very well, so I decided to make my own.
Well, after years of diligent research (well, actually it was more like days and not very diligent), I decided this method had the most promise:
Okay for the technically challenged, the basics are:
1. Fast discharge the battery from 1.2-1.4 volts, down to 1 volt.
2. Discharge it slower to about 0.4 volts. Then recharge and see if it works.
This may have to be repeated several times.