

I don’t have any answers - but now I wonder if your idea would be easier when working with one of the fancier smoke detectors with voice alerts. Those have pre-recorded voice alerts that “speak” when an alert occurs, rather than beeping. Those pre-recorded messages must be stored somewhere in the smoke detector.



Yes.
Not only that, the current generation of smoke detectors have sealed batteries so you can’t even open them up to change batteries or anything. So once they expire in 10 years they start their incessant “I’m dying” non-stop beeping - that’s when you dispose of the entire smoke detector and buy a new one.
I’ve read that they don’t detect smoke as well after 10 years anyway (e.g. even more false alarms) so it’s probably for the best to get rid of old ones.