Today, I changed the batteries in all my smoke detectors. I noticed that the battery light in one was blinking. Instead of only replacing the one with a new normal 9v battery, I ordered a pack of 10-year lithium 9v batteries and replaced them all. Now I don’t have to worry about changing them for a handful of years.
Edit - Funnily enough, dinner put them to the test. I was going to test them tomorrow when the kiddo is at daycare.
Where are you getting smoke detectors that last that long?
It really depends, but more and more of them last 10 years and have a battery built in. I’d say most of them now last 10 years. At least, in the US.
I’ve seen them say that on the packaging, and then 6 years later they’re emitting their EoL alarm.
That can happen if the device is installed in a less-than-ideal location. UV, dust, debris, etc can affect the lifespan of the detector.