Up until recently there used to be these special batteries you could put in your fire/smoke/CO alarm that would contact you on your smartphone if the alarms went off while you were away.
They don’t make them anymore, and if you want anything equivalent, it seems like you have to buy into an entire “smart home control system” or whatever they’re called, and I don’t need or want that.
It doesn’t have to be a battery, but is there some way I can set up my alarms to contact me without surrendering all my privacy? The alarms I have now also aren’t hard-wired into the house, which could present a problem, but that’s why the Roost batteries were so nice!
I have my smoke / CO detectors, KIdde Z-Wave units, tied to my Home Assistant setup. HA will push a notifier to my phone if the smoke or CO alarm goes off and it’s able to track the battery life and let me know I need to change them before they start beeping.