The Venn diagram of people who don't change batteries, can't reliably make toast, and want a feature rich smoke alarm is non-empty based on this thread.
Re:Whatever happened to IoT smoke alarms?
by AstralStorm on Sunday April 11, 2021 @10:10AM
(#26770483)
Well, you could have a mains powered rechargable battery (or supercapacitor) backed detector.
Then again, it better be designed so that the sensor part is replaceable and it fails loud.
(Though neither supercapacitor nor nickel-* cells are very expensive, we put them in random MP3 players for $10 a pop.)
The feature richness is a scam though.
The half-life of commodity rechargeable batteries is significantly less than the half-life of Americium.
And people who don't proactively replace smoke alarm batteries are unlikely to proactively change the alarms...changing out an alarm is a bigger job than changing batteries.
A smoke alarm is not a consumer product.
You could replace the cheap detector part and keep the expensive smart part.
Of course the manufacturers would rather have you buy the smart part over and over again. Sounds like a great idea and now they have nothing.