Set up two of these with no problems, monitoring alarm state and battery % on my dashboard.
Batteries went bad on one in my garage. The alarm chirped, but given that HA looked fine I thought it was a bad backup battery on garage door opener next to it. Finally figured it out and took the alarm’s batteries out, but HA dashboard hasn’t changed. Looking at it in Devices, only “Last seen” and “Node status” indicate anything different from the other one I have.
How do I approach fixing this? Do I need an automation to notify if “Last seen” and “Node status” change state? Did I miss something about basic practices that would have led me to have done more?
Given the importance of smoke alarms, this is a major issue for remote monitoring and others should know about it.
You would need to automate this yourself, HA doesn’t do anything with “last seen” on its own. The allowed threshold for missing device updates is different for every device and every person.
“Batteries when bad” is also a specific scenario that may not be noticeable except for checking “last seen”. For the more common case of Low Battery, that was something you could previously automate but no longer can for the time being. https://github.com/home-assistant/core/issues/150898
Last Seen should update whenever the node wakes up. If last seen is older than 3x the wake-up interval then I generate an alert. I use 3x as occasionally wakeups are missed on battery devices. It’s not common, but it happens for reasons I don’t know.
