Well, not epic battery life. But the epic life of a cheap mechanism.
In January of 1985 I built a clock in shop class at high school. I purchased the clock mechanism for $2 or $3 (I forget) from the teacher. Just a cheap, plastic mechanism that runs on one AA cell.
The clock has been in continuous use since. I’ve replaced the cell a few times, but the mechanism still keeps perfect time.
After some Googling, I think the battery mine uses is something like a CR123a or CR2 type battery (I’d have to actually look at the battery to verify exactly what it is), which now that I think about it I vaguely remember being what many old SLR film cameras used, I think. I also kind of vaguely remember those being called “camera batteries”, and I assume the CR stands for camera. So while somewhat more specialized than common AAs and such, it doesn’t seem to be complete unobtanium like something that was Radio Shack only.
I made a clock in junior high, 1991 or thereabouts, and with what is as best I can tell an identical mechanism (complete with smoked plastic back, ridged set wheel, etc.). It likewise has been going strong on my parent’s mantel for all that time. Seems to keep better time than anything else in the house.
Guess I can sleep soundly this winter! 
I tried to put in a “we’re not worthy” image and failed miserably. Some day.
C = lithium manganese dioxide
R = Round
CR = Round lithium manganese dioxide
CR cells may be button cells or “short AA cells”
IMHO old meters and old PC’s are more likely to use the CR2 than the CR123, which I think (but may be wrong) was more common in cameras.