How to Repair a Rechargeable Battery

Updated February 21, 2017

No need to throw your used rechargeable batteries away. If your rechargeable battery no longer holds a charge, it can be repaired to work like new. Repairs on rechargeable batteries can work on cell phones, computers, appliances, cars, AA, AAA, D, A, C batteries and many others. The most commonly used rechargeable batteries include Nickel Cadmium (NiCd), Nickel Metal Hydride (NiMH) and Lithium Ion (Li Ion) batteries. Save money on new batteries by bringing your rechargeable batteries back to life.

Confirm that your battery recharger is working. If your rechargeable battery charger is not operating properly, the repair should be to the charger and not the battery. To test the recharger, place a working uncharged rechargeable battery into the charging station. If this battery successfully charges, then the other dead battery should be repaired.

Test your rechargeable battery using a digital multimeter or battery tester to make sure it has no charge.

Test a fully charged rechargeable battery on the multimeter or battery charger. This reading will be used as a level to target for fully recharging a dead rechargeable battery.

Put on safety gear including a long sleeved shirt, safety googles, and insulated gloves. This is a potentially dangerous procedure and all precautions should be taken to protect your skin and eyes.

Locate the positive and negative ends on the rechargeable battery. On a AA battery, the positive end is the raised or bumpy end, the negative end is usually flat.

Use the 12-amp, 5-volt AC/DC charger to revive your rechargeable battery. Place the black clamp on the negative end of the rechargeable battery. Quickly and lightly tap the red clamp onto the positive end of the rechargeable battery once or twice. The battery should spark.

Hold the red and black clamps in place for a maximum of two seconds. The red clamp should only be on the positive end of the rechargeable battery; the black clamp should only be on the negative end. Release and check the charge on the battery. A fully charged AA rechargeable battery should read between 1.2 and 1.3 volts on a multimeter.

Repeat the process in reviving your rechargeable battery until the desired charge is reached.


Try placing the rechargeable batteries in the freezer for 24 hours to see if that revives them before using the shock process. This procedure can also be done with a welding gun.


This battery repair process should be done by individuals experienced in working with electricity. It is a very dangerous process. During this process the battery could explode and spray battery acid. The battery could also catch fire. This article is for information purposes only. Any damage or injury done to persons or property are the sole responsibility of any individual attempting this process.

Things You'll Need

  • Dead rechargeable battery
  • Safety goggles
  • Multimeter or battery tester
  • 12-volt 5-amp AC/DC charger
  • Insulated gloves
  • Long sleeve shirt
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About the Author

Deb Katula has written and researched for Societe Generale, FIMAT, Nikko Securities, Chicago Mercantile Exchange and Arthur Anderson. She holds an MBA in economics and finance from the University of Chicago; a Japanese language fellowship from Harvard; and a Bachelor of Arts in business/psychology/Asian studies from Augustana College.