Resetting the memory in a NICAD battery will revive dead rechargeable NICAD batteries. The resetting process will not only revive the NICAD battery but also enable the battery to hold a charge for a longer period of time. As NICAD rechargeable batteries are used and recharged, crystals build up within the battery, blocking the ability of the battery to hold a charge. Resetting the memory in NICAD batteries is a process in which NICAD rechargeable batteries are "jumped" like a car battery to remove the crystal build-up, allowing the battery to work like new.
Test the NICAD batteries using the battery tester to determine whether the NICAD batteries are fully discharged.
Locate the negative and positive nodes on the NICAD rechargeable battery. The negative node is on the flat end and the positive node is on the raised, bumpy end of the battery.
Put on all recommended safety gear.
Attach and hold the black clamp from the 12-volt battery charger to the negative end of the NICAD battery.
Rap the positive end of the battery with the red clamp from the 12-volt battery charger. This may cause the battery to emit sparks. It is part of the process of resetting the NICAD battery's memory.
Hold both the black and the red clamps on the appropriate negative and positive ends, respectively, of the NICAD battery for 1 to 3 seconds maximum. Release both clamps.
Retest the NICAD battery with the battery tester to determine whether the NICAD battery's memory has been fully reset.
Repeat the NICAD battery resetting process if necessary.
Take precautions to protect your skin, eyes and hands during this hazardous process. This hazardous process is best performed by an experienced electrician.
Do not overcharge the battery, because doing so may lead to a fire, explosion, or spraying acid if mishandled. If you attempt this dangerous process, do so at your own risk. You could injure yourself or others, or cause damage to property.