

Where I live, smoke detectors come with a guarantee that the (9v) battery will keep them operational for at least 10 years.
When the battery is low on charge, they start beeping in regular intervals and from when the beeping starts it still takes a year or two for them to run out. Which you will surely notice at some point when you’re at home.
So I don’t really understand why someone would need a notification.
I guess a notification could be nice if you have a hearing deficiency, but instead you could make a calender apointment to replace them in 8 years just to be safe.
The alternative is getting smart smoke detectors that are compatible with home assistant and that know their own battery level.
Edit: this last bit still applies and is one way to do it
Then you’d need to selfhost home assistant on some always on device. And buy compatible smoke detectors.
https://www.home-assistant.io/
https://community.home-assistant.io/t/smoke-sensor-with-battery-status-in-ha/357762
Ooooh, that makes much more sense, thank you!