How to Fix and Repair Rechargeable Batteries

By Deb Katula

Use a battery tester to check your batteries' power levels.
i battery tester on white image by JoLin from

Many appliances, tools, toys and electronics run on batteries, making them more portable than ever. Rechargeable batteries have become a popular power option as they last longer and are considered "greener" than other battery options. But eventually even rechargeable batteries fail to hold their charge. Rechargeable batteries can be fixed by zapping them with a high volt of electricity, a concept which is similar to that of jumping a car battery.

Gather your dead rechargeable batteries. Check their power levels on a battery tester or a digital multimeter to make sure they have been fully discharged.

Use a 12-volt 5-amp AC/DC charger to repair rechargeable batteries. Using the appropriate safety precautions (see Warnings), place the black charger clamp on the negative side of the battery.

Lightly tap the positive end of the battery once or twice with the red clamp on the 12-volt charger. Sparks may shoot out of the end of the battery.

After tapping the rechargeable battery, place both clamps on the appropriate positive and negative ends of the battery and hold for a maximum of three seconds.

Test the charge on the rechargeable battery once again with a battery tester or digital multimeter. Repeat the process until the battery is fully charged.