Perhaps 35 years ago I thought to replace an alkaline battery pack for a PC's CMOS memory and RTC with a 3v coin cell. The first step was to solder leads onto i

Perhaps 35 years ago I thought to replace an alkaline battery pack for a PC's CMOS memory and RTC with a 3v coin cell. The first step was to solder leads onto it. The second step was to leave the room in a hurry. The cell blew its end cap off and smoked vigorously for a while but no real damage was done.