On Mon, 19 Mar 2018 12:55:31 +0000, alan_m wrote:

I have some optical smoke
detectors and use fresh Duracell Industrial PP3 (they re-branded Procell
to Industrial a few years back). I put date stickers on my alarms on a
battery change and all the alarms I have all start chirping after 14
months (I replaced all my alarms, 5 off, at the same time).

Yes -- mine last longer, in my detectors:-)

Just checked: one "Procell", expiry date MAR 2018, in a ionization detector. Got
two optical detectors, with lifetimes handwavingly well greater than 14 months,
but not able to check now.

None of these were expensive!


Thomas Prufer