The message
from Matt contains these words:

Absolutely. The zinc-air PP3's despite costing an arm and leg and
theoretically offering a higher mAh than alkalines are useless for low
current applications such as smoke alarms.

The local fire brigade in association with the local council gave away
loads of smoke alarms with "10 year" lithium PP3s fitted. About three
years later the batteries are dying.
This wouldn't matter except that there's a pop-rivetted retainer over
the battery so you "can't" replace it.

--
Skipweasel
Pay no attention to that man behind the curtain.