Don't Throw It in the Landfill: "How to Repair a Cordless Drill With Broken or Missing Battery for About $3 (or Less)"

Many people have the battery in their cordless drill go out, and simply throw it away. In fact I obtained 2 cordless drills with missing batteries at a yard sale in a free box, as you guessed for free. This instructable shows you how to turn a cordless drill with a missing or broken battery back into a working drill again.

The materials you will need for this are: (see above picture for images)

   • An AC 120 volt to DC 12 volt transformer or AC 120 to DC 18 volt transformer, these are the two main power supplies for cordless drills, however if your drill says another voltage then get the appropriate transformer for that drill. Basically you need a power supply that changes 120 volts AC into your drills voltage DC. ( This is about the only thing that will cost you money assuming you already had the drill or got it for  free)

   •  Screwdriver to disassemble the drill

   • Cordless Drill (obviously)

  • Electrical tape

Step 1: Take Apart Your Drill

This part is simple just remove the screws (save them!) and separate the two pieces of your drill carefully. You want to separate the pieces carefully, so you don't drop any mechanical pieces out of the drill. This will be probably different for your drill than mine.

Step 2: Cut the Wire Between the Trigger and the Battery Terminal

Between the battery terminals and the speed trigger there should be a wire, cut this wire close to the battery terminals and use wire strippers to strip about an inch off of it. See picture for further illustration on this.

Step 3: Cut the Plug Off of Your Transformer and Strip Wires

On your transformer if there is a circular plug (called a barrel jack), cut the 2 wires leading to it. Next strip about an inch off of the end of the wires leading to your transformer. Then twist the wire strands together. See the photos for a step by step illustration.

Step 4: Splice the Wires

Image 1:

Now that your wires are stripped to around the same length, cross them in an X form, where the center of the x is about midpoint of the 2 stripped sections of wire

Image 2: 

Whichever wire is on top (closest to you) bend away (or back) and then down, the wire will make a upside down L shape around the back wire.

Images 3 and 4: 

Now take the other wire, bend it towards you (or forward) and then down, twisting it around the first wire, making a M shape

Image 5:

There are two directions to twist, you do not want to twist the entire wire, just the splice. I recommend using your thumb and forefinger of each hand to twist the wire. One wire will go clockwise (or towards you) the other wire will go counter clockwise (or away from you), pinching hard, twist only the spliced section, slowly moving towards the insulation with both hands if you are using solid core wire, or thick gage wire once you get near the ends, I strongly recommend you wear gloves or use needle nose pliers to finish up the twist if you got close enough to the same length of stripped wire, and made your X close enough to the center of the two wires you should end up with both ends of the wire running out just at, or before the start of the insulation and a super strong splice.

Image 6: 

Wrap electrical tape around each set of wires individually being sure to cover any exposed metal so that it will not touch the metal from the other wire and then tape the two bundles together to make a clean, finished, and insulated job that will not short out.

Step 5: Reassemble Drill

This step is pretty self-explanatory, put the screws back in to where they belong and tighten them. This will be probably different for your drill than mine.

Step 6: Test

Another easy step, test the drill by plugging it in, pushing the trigger, and possibly drilling something. The picture is a file photo not my drill lol.