what amperage? 2, 10, 50....yeah I posted that question a while back. I got a good answer worht trying but I haven't tried it yet.
Hook the ground of a car battery charger to the ground on the drill battery. Hook the positive of the drill to a file. Scrape the positive lead of the charger over the file. The little jolts of power from the lead alternately making and breaking contact is supposed to clean up the battery. I think I have that right. ANyway, what's the worst that could happen?