I was in dire need for a battery powered drill, but my good one was at my local Makerspace and I could not be bothered to drive over there at 0100 in the morning.

I remembered that I had bought one some 15 years ago in a supermarket. After I dug up my basement looking for it, I found it in the store-room with a dead battery.

I will show now what I did to reanimate it, for fun and... fun. ;-)

Step 1: Take Apart the Battery

The battery pack was held together with 4 screws. After loosening them, it fell apart into three pieces:

old batteries (dump)
top cover with contacts (need new wires to go to the new battery)
lower case (needs holes for battery wires to go through)

Step 2: New Energy

I decided to use a lipo battery pack as my new power source. My drill originally had a 12V power source, so I needed a 3 cell LiPo pack.

I had an old Macbook battery with a broken cell sitting on my desk for ages, and took the occasion to finally rip it apart to build a new battery out of it.

This is quite easy, but I found no instructable detailing how its done.

So I made one! =)

Step 3: Build Top Case Connector

Easy step, find a matching battery cable, solder it to the contacts in the top case.

Maybe your drill is old enough that it doesn't matter, but watch out for polarity anyways!

I want to have the battery connector outside of the plastic case, thats why I left the cables that long.

Step 4: Lower Case

Now I had a problem. I needed to drill holes to get a working battery for my drill. The battery was empty (after sitting on my desk for month).

Adjustable desk power supply to the rescue!

I put 2x two holes next to each other, broke out and filed of the middle to have two long holes.

Step 5: Assembly

The battery fits nicely. The reason why I wanted to put the wiring on the outside is:

I need a easy way to access the balancing port for charging and use of a lipo warner (recommended)
I want to be able to disconnect the lipo from the contacts

Happy drilling! :-)