It seems the batch of Energizer CR2032 lithium cells I bought a while ago reached the end of their shelf life:
In point of fact, I replaced three CR2032 cells this month, all with anomalously short lives: one month counts as a complete failure. The Energizer date code
YA isn’t helpful in determining when they were manufactured or what the shelf life might be.
Admittedly, I bought that batch in late 2009, so they might have used up most of their shelf life on somebody else’s shelf. There’s no way to know.
It’s not clear one can buy known-good cells from any supplier these days, as the counterfeiters evidently get genuine holograms from the same factory as the Brand Names.