On Aug 24, 2:35*pm, wrote:

.....And shouldn't be a problem as mine are mains supplied. The
interlink is wire.

I had very strange symptoms with my Kidde alarms, and found it was due
to the neutral not making contact at one of the (interlinked) alarms.

All alarms still worked, and the nuisance beeping was neither a normal
"alarm", nor a low battery warning, nor localised (or even always
present!) at the poorly wired alarm.

Cheers,
David.