Can I Fix Dewalt Batteries?

Zap It

• One trick to revive a dead DeWalt battery pack is the voltage zap technique. This trick relies on the likelihood that only certain cells in the battery pack are dead. A portable tool battery is made up of individual cells wired together in series to produce the voltage required to run the tool. A dead cell in the pack can stop the flow of current to the rest of the cells, leaving you with a battery pack that appears totally dead.

Test Cells

• To repair the DeWalt battery pack, remove the screws holding the top of the pack and lift the top off. Inside, you will see the interconnected cells. Draw on paper how the cells are arranged. This will help when you reassemble the battery pack. Note which ends are soldered together and the polarity of the cells at each connection. Use a battery tester to check each cell in sequence. Some will test OK and others will not. Mark the bad cells. After you are done testing, use a soldering gun to desolder the bad cells and pull them out of the pack.

12-Volt Jolt

• Take the red lead from a 12-volt battery charger and touch it to the positive end of the bad cell. Then touch the black lead to the negative end and hold them there while you count to three. Retest the cell. If it still tests as bad, repeat the 12-volt zap. In most cases, the cell will be revived. Repeat the zapping on each bad cell. If they all test good, resolder the cells back into place and reassemble the whole battery pack. If some cells stay dead after zapping, replace them with cells known to be good and reassemble the battery pack. Charge the repaired battery pack with the DeWalt charger overnight. It should be good to go.

Recondition Pack

• If your DeWalt or other power tool battery pack holds a partial charge, you can try another trick that may recondition it. Run the tool with no load until the battery is discharged. Charge the battery back to full capacity with the tool’s charger. Run the tool with no load once more until the battery again is discharged. Recharge it again. Hopefully, it will be good to go. This reconditioning process can resurrect power tool batteries that haven’t been used for several months. It also is good preventive maintenance and should be done once a month to ensure long life for your battery pack.