If you have a dead rechargeable battery, don't throw it away. Try the following trick that might bring it back to life. At least you have nothing to lose.
Usually, Ni-Mh rechargeable batteries , if not charged properly, may retain a “memory” or even refuse to be recharged altogether. So if you have a Ni-Mh rechargeable battery that no longer refuses to charge, then before throwing it in the recycling bin, try the following trick. All you will need is a second rechargeable battery in good condition and…. barbecue tongs!!!
Take a fully charged battery to the one that is “dead” (of the same type) and hold them so that their two negative poles are joined. Then hold their two free positive poles between a pair of barbecue tongs. In fact, just short-circuit the two positive poles. Not for long, but only for 30 seconds. See how it is done, exactly, in the video below:
This trick doesn't promise that it will work every time or on every battery, nor that if it works once on a battery, it will work again for that battery. Nor that it will revive the battery with the same charge power it had before it died. However, you simply don't lose anything by doing it. You were throwing it away anyway.
Anyway, we wish you good luck.
