When a lithium-ion battery is over-drained, its protection circuit turns it off, making it dysfunctional to be used, or recharged by the charger.
This may happen due to overuse or leaving the battery for too long on the charger. For example, using an impact wrench for too long can drain the battery voltage so low that the charger would fail to recognize the battery for charging. Here are a few methods of reviving lithium-ion batteries that appear completely dead.
- Using another battery:
For example, your 18V impact driver with a Makita 18V lithium-ion battery has stopped working. When you put the battery on charge, the charger renders the battery unserviceable. In this case, you can take another 18 V battery (does not matter what brand it is), and connect the batteries with the help of metal clips. Make sure the positive end is connected to positive, and the negative end is connected to the negative end. It can be dangerous if they are not connected in the proper order. Once they are connected, the voltage of the dead battery raises. You can then disconnect the batteries and connect the battery to the charger to check if it is being recognized by the charger. If the battery’s volt levels have been raised enough, the charger will recognize the battery and start charging.
- With the help of an AC adapter (for example an old phone charger):
You can fix a dead lithium-ion battery up in few minutes.
- Cut the end of an old mobile phone charger that is not in use.
- Separate the two wires and remove their cable covers. They are going to play the role of booster cables. Never mix up the positive and negative ends. The striped or solid white wire is the positive end, and the black wire is the negative end.
- Remove the screws of the battery pack.
- Open the battery case.
- Remove the two plastic pieces on the sides. They help in removing the battery from the drill when they are pressed in.
- Pull out the battery pack.
- Check the volts level with the help of a multi-meter. For example, an 18V impact wrench would have an 18V lithium-ion battery. In this case, set the multimeter on 20 volts to get the most accurate reading.
- To check the voltage levels, connect the red probe to the red terminal (positive ends) and the black probe to the black terminal (negative ends) and check the reading on the multimeter.
- Take the ac adapter/the old mobile phone charger that you used to create a booster, and touch the black wire to the negative terminal and the white or stripped wire to the positive terminal. Keep doing this on and off for about a minute.
- Check the voltage of the battery with the help of the multi-meter. The boosting process would have raised the voltage levels.
- Put the battery pack inside the battery case and secure the plastic and the screws.
- Connect the battery to the charger to check if it is getting charged now.
One most important point to remember if you own a power tool that runs on the lithium-ion battery is that never completely discharge the battery. A completely drained lithium-ion battery cannot be recharged by the charger.