Cordless drills run primarily on a detachable and removable Black & Decker cordless drill battery pack. When your cordless drill stops holding a charge, there are a few factors that come into play. But most commonly, you can trace the issue back to your battery pack or external battery charger. While you can rebuild the battery pack, it is a complex procedure. In many cases, you can solve the problem by repairing the battery charger itself.
Remove the battery pack from the charging unit. Do this by pressing on the release buttons on either side of the battery pack. Disconnect the charger's power cord from the nearest electrical outlet.
Blow out all dust and debris from within the charger's contacts with a can of compressed air. Use a medium-grit file to file down the contacts slightly. This is only to clean the charger's contacts of any accumulation of dirt or battery acid.
Apply some rubbing alcohol to a clean wash cloth or paper towel. Thoroughly wipe down the inside of the battery charger's compartment. Allow five minutes for the alcohol to dry.
Plug in the battery charger and insert the battery pack into the charger. You may have to remove and re-insert the cordless drill battery for Milwaukee several times before making a connection, depending on how much dirt has accumulated on the charger's contacts.
Refer any major electrical repairs to a power tool repair technician. Dismantling the charger yourself will void your drill's warranty.