The thick black smoke alerted me, only took 5 minutes of an overheating LI drill battery for this...
What brand of battery/charger was it? Not that it totally matters, just curious.
Sears Craftsman 12 volt drill driver. The battery was totally dead, I took the charged battery out of the charger and put the dead one in and walked out of the garage to fix my busted mailbox. I always tell people to keep an eye on the charger for a couple minutes to make sure the battery is taking a charge and not overheating the charger or battery. I was an engineer in the Motorola Battery Division from 1996-1998 when LI batteries were fairly new, I should have known better but I was pissed that someone smashed my mailbox and rushed out of there...