On Sun, 27 Nov 2011 16:36:55 +0000, Chris K
wrote:

Bought and early Casio lithium powered digital watch circa 1980 labelled
'5 year life'. Buttons stuck quite quickly making it impossible to
operate light or change settings so it was put to one side. Came across
it earlier this year and it was still going after 30 years - probably
because the light had never been used.

Don't know whether there are any records for this but this must be near
the upper limit.

Chris K

I couldn't find any statistics for digital watches.

Incidentally, Smart Meters require similar long battery life. 10 to
20 years specified battery life is typical. Here's one product that's
been going for 25 years:
http://www.tadiranbat.com/pdf.php?id=waterworld-article
They use lithium thionyl chloride chemistry.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558