I seem to have portable drills that have battery packs that eventually fail. Sometimes I can get replacement battery packs but sometimes I can't. I have seen workable drills with bad batteries at yard sales for just a few dollars. Recycle and reuse them.
In the example I show here I actually bought these cheap drills for the battery packs and chargers so I had the drills but no batteries.
Almost any drill powered by 9 VDC to 18 VDC battery packs can run off a car battery. Just add a convenient length of low voltage wire and a couple of battery clips and you have a handy recycled drill to use anywhere there is a 12 volt battery. I carry one in my car and have another one in my boat.
Some soldering is required but the whole project shouldn't take more than about 30 minutes.
Obviously I should have searched Instructables before I published this. There are already a number of IBLs you can find by searching "12 volt drill". So now there is one more. (:
Step 1: Tools and Parts
Drill with dead or missing battery pack
Landscape low-voltage 16/2 wire (Lowes #210913, 50', enough for 2-5 drills) $13
Battery clips (Lowes #29745) $3