Craftsman Not-So-Cordless 13.4v Drill

This may void your warranty :-)

Short summary

Both battery packs for this drill were dead, and re-packing was not something I wanted to deal with this weekend. I have two battery pack cases, so I used one to make an external power adapter for the drill.

The 12v battery has a fully-charged open circuit voltage somewhere around 13.2v, which is safely within the nameplate rating on the drill. However, unlike Ni-Cd, the voltage droops quite a bit based on the load. With a fully-charged battery and the drill running unloaded and flat-out (no PWM, trigger fully depressed), the voltage droops to 12.3v.

Hot glue was used to cement the battery contact assembly in place.

An in-line 20A fuse keeps things from melting should I touch the wrong things together. :-)