Note and mark the silver cardboard insulator where the wires go from the terminal, through the silver insulator and into the battery pack. Again, noting where these wires go will make the battery pack easier to assemble.

Use a voltmeter to check which leads on your cordless drill battery pack are positive and negative. Mark these as positive and negative to assist you in later reassembly.

Wrap the exposed metal band with electrical tape to insulate it during the battery-reconditioning process. This metal band will be hot during the reconditioning process, and wrapping it will protect you from injury.

Prepare for the reconditioning process by locating the positive and negative ends of the first cell. Prior to reconditioning this cell, prepare your 12-volt power source and put on safety glasses, insulated gloves and a long-sleeved shirt for protection.

Release the alligator clamps and use the battery tester to determine if the battery cell is fully charged. If not, repeat the zapping process. The cell can be zapped up to 10 times.

Access the batteries by cutting off a portion of the shrink wrap covering the batteries. You will need access to the tops and bottoms of the batteries. The cells within the shrink wrap are internally banded together. Leave these bands connected.

Open power tool battery case by removing the screws on the outside of the battery case
with a Phillips head screwdriver. Organize the screws and any springs or additional items that fall out of the case in a small container.

Test the cell again with the battery tester to verify that the cell has been repaired and will take a charge. If the cell still does not take a charge, repeat step 8 for a maximum of 10 times until the battery holds a charge. If the cell will not hold a charge after 10 attempts, it will have to be replaced entirely.

Choose one of the battery cells that you marked with tape in the previous step to be repaired. Locate the positive and negative ends of the cell, which can be identified by their flat or raised surfaces, respectively.

Remove the Dewalt battery pack from the Dewalt cordless tool. Use a small screwdriver to open the Dewalt battery case. Set the screws aside for later reassembly.

Prepare to "zap" the cell back to life using the 12-volt power source. Hold the black alligator clamp to the negative end of the battery while holding the red alligator clamp to the positive end of the battery. Hold this link for no longer than two seconds.