Last Updated on 15 July 2025 by Maelle
Many appliances, tools, toys, and electronics run on batteries, making them more portable than ever. Rechargeable batteries have become a popular power option because they last longer and are considered “greener” than other battery options. But even rechargeable batteries eventually lose their charge. Rechargeable batteries can be repaired by zapping them with high voltage, a concept similar to that of a car battery. That’s why tout-reparer.fr offers you its guide: How to Repair Rechargeable Batteries. Steps to Reuse Rechargeable Batteries:Step 1 Gather your dead rechargeable batteries. Check their power level on a battery tester or digital multimeter to ensure they are fully discharged. Step 2
Use a 12-volt, 5-amp AC/DC charger to repair rechargeable batteries. Taking proper safety precautions (see warnings), place the black clamp of the charger on the negative side of the battery.
Step 3
Lightly tap the positive end of the battery once or twice with the red clamp of the 12-volt charger. Sparks may fly from the end of the battery. Step 4 After tapping the rechargeable battery, place both clamps on the appropriate positive and negative ends of the battery and hold them for up to three seconds.
Test the charge of the rechargeable battery again using a battery tester or digital multimeter. Repeat the process until the battery is fully charged.
How to Fix a Dead Rechargeable Battery
Items You’ll Need
Freezer
Dead Rechargeable Batteries
Plastic Wrap
Aluminum Foil
Digital Multimeter or Battery Tester
12-volt AC/DC charger
- Protective gloves
- Safety glasses
- Rechargeable batteries are used to power countless games, toys, and devices. Families can spend small fortunes just trying to keep their game console controllers working. Unfortunately, even rechargeable batteries don’t last forever. There are a few tricks to try when trying to revive old or dead rechargeable batteries. Just because rechargeable batteries are dead doesn’t mean you should throw them away.
- Reviving Dead Rechargeable Batteries
- Wrap each dead rechargeable battery individually in plastic wrap. Group the foil-wrapped rechargeable batteries together and seal them tightly. Place the discharged rechargeable batteries in a freezer overnight. Remove the discharged rechargeable batteries from the freezer. Allow them to warm to room temperature. Check the charge in each battery using a battery tester or multimeter. If a battery hasn’t recharged, you may need to recharge it.
- Recharge Rechargeable Batteries
- Gather all the dead rechargeable batteries you want to revive. Identify the positive and negative ends of the battery. The positive end always has a raised end, while the negative end is flat. Put on all safety equipment, including safety glasses, gloves, and a long-sleeved shirt.
- Locate the red and black clamps of the 12-volt AC/DC charger. Place the black clamp on the negative end of the battery.
Hold the black clamp in place on the negative terminal of the battery. Take the red clamp and lightly tap the positive end of the battery. Sparks may occur at this point. Tap the red clamp again to reach the positive end of the battery and hold it for no more than two seconds.Remove all clamps and test the battery charge with a multimeter or battery tester.
Tips
Always wear eye, skin, and hand protection.
Warnings
This is a dangerous procedure. Anyone attempting this process does so at the risk of injury and/or property damage. The recharging process must be performed by a person familiar with electrical work.There is a risk of fire, explosion, and battery acid splatter during the charging process.
How to Test 1.5-Volt Batteries with a Voltmeter
Most batteries used in toys and electronic devices are 1.5-volt alkaline batteries. These batteries, commonly referred to as A, AA, AAA, C, and D, come in different sizes but all have the same voltage. If your household is like many others, you have several of these batteries lying around, and you may have lost track of which ones are good and which ones are no longer charged. You can use a voltmeter to quickly test them.
Step 1
Turn on the voltmeter and set the meter’s range to 2 volts DC.
Step 2
Place the battery on a flat, stable surface so that it doesn’t roll when you drop it. You’ll need both hands to test the battery.
Step 3
Place the positive (usually red) lead of the voltmeter on the positive terminal of the battery. The positive terminal of the battery is located at the end marked with the “+” symbol.
Step 4
Place the negative (usually black) lead of the voltmeter on the negative terminal of the battery. The negative terminal of the battery is located at the end marked with the “-” symbol.
Take note of the voltage indicated on the voltmeter. A new, fresh battery can display a voltage of up to 1.58 volts. Batteries displaying a voltage below 1.3 volts may begin to show reduced performance, and batteries below 1.0 volts should be replaced.
You now have all the information you need to repair rechargeable batteries! The entire tout-reparer.fr team remains at your disposal in the blog’s comments section.
