@sven gotta be honest, still like my nest protects combined with my ecolink firefighters. Been very reliable and hard wired. Though that's a very good deal on those smoke detectors.
Not always an option, and these are battery powered.
Edit: but I’ve moved on to the ecolink firefighter with dumb battery powered detectors too 
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That's why I mentioned hard wired. That said, I still like the nest protects (available in battery only form as well). It would be nice if first alert came out with a hard wired version as well. (also wish there were other manufacturers that would do z-wave/zigbee)
Yes these are battery powered. I have been using these for quite some time and wanted to add them to some different rooms.. One thing I did learn though is that these have a set expiration , i think it is 7 years after activation, then they will constantly beep until you hit them with a baseball bat. While I understand that all detectors should be replaced for safety, I don't know if the Ecobees have the same limitation.
