Probably 20+ years for a lithium coin cell... basically the shelf life of the cell. I have a card of 24 year old CR-2032's that are still above 3V, and no sign of leakage.
BTW, never handle a coin cell (particularly in watch applications) with your fingers... your grubby fingerprints are rather conductive and can discharge a cell surprisingly quickly. Also note the clock chip has 512 bytes of RAM in it. ---------------- > Assuming you are going to run it off a battery. What’s the self discharge rate on a reasonable battery? _______________________________________________ time-nuts mailing list -- email@example.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.