How to Restore a NiCad Battery

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Things You'll Need

  • Dead rechargeable NiCad battery

  • Trickle charger

  • Digital multimeter or battery tester

  • Protective eye-wear

  • Protective gloves

  • Long-sleeve shirt

As you use nickel-cadmium (NiCad) rechargeable batteries and continuously recharge them, they hold less and less of a full charge over time. Within the rechargeable batteries a dendrite crystal substance, also known as battery charge memory, builds up and decreases the charge capacity. Eventually, when the rechargeable battery no longer holds a charge, the dendrite crystals have built up. To repair NiCad rechargeable batteries, you need to remove the dendrite crystals using an electric current.


Step 1

Locate the black and red clamps on the trickle charger.

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Step 2

Test the NiCad rechargeable battery to make sure it is fully discharged.

Step 3

Locate the positive and negative ends of the NiCad rechargeable battery.


Step 4

Protect your eyes, hands and skin before beginning the rechargeable battery "jump start" process. This is a dangerous and hazardous procedure.

Step 5

Hold the black clamp on the negative end of the battery.


Step 6

Tap the red clamp on the positive end of the battery one or two times. Sparks may crack from the end of the battery.

Step 7

Immediately hold the red and black clamps on the battery for 1 to 3 seconds only.


Step 8

Use the battery tester or multimeter to determine the battery charge.

Step 9

Repeat the process until the battery is fully charged.


Do not overcharge the battery or it may explode, catch fire or spray acid.


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