According to Google, most recent code consider wired and wireless interconnect to be equal and there are no state building codes that require wired interconnect.
Home Depot has several models
https://www.homedepot.com/p/Kidde-10-Year-Worry-Free-Hardwired-Combination-Smoke-and-Carbon-Monoxide-Detector-with-Voice-Alarm-and-Ambient-Light-Ring-21029893/305261308
Requires WiFi to set up. But not to work as a detector or to interconnect.
Not here in PA. Wired or wireless interconnect is acceptable.
The nest battery version claims 10 year life,, their hard wired version claims 10 year for backup (which generally makes sense since it's hardwired)
It uses bluetooth and wifi to onboard to the nest app, after that it's local. It uses 802.15.4 at 2.4 GHz for the interconnect which doesn't require wifi itself. (you can turn off all the wifi in your home and it still works just fine). The only time it uses lan is when it notifies the app on your phone.
firmware version 1.30 is out - supposed to fix the appearance of falling of the network like mine does.. i will flash it soon.. but I cant get it to respond right now since its "fallen" off the network 
Firmware: 1.30 (released 11/2023 as OTA)
I updated a few days ago (went fine), but I didn't have any falling-off issues previously (well, that I'm aware of anyway!)
Mine's always been paired S2 -- no idea if that matters or not.
The update for the Z38 extender has the same release notes, so must be same bug they're squashing there too.
Is that before even starting? Can you power cycle the device and hub?
Or try the drivr version of the updater. Z-wave S2 device - how to (maybe!) update firmware with HE It says the directions are for S2 but could for any security.
I did the 1.3 update over the past weekend no problem (was and still am using Jeff's driver).
I used the steps in the post Jeff linked above since my ZW stuff is all S2, but those steps should work just fine with no-security devices too.
I'm not using security.
Won't the built in app work with no security?
I've updated several other Zooz devices with it.
It should. But I haven't used it in a long time, so I don't have any recent experience to compare.
Yes, it should, but the driver may work since the built in does not seem to want to.
I have no idea what the problem is, I am just giving suggestions of possible solutions.
It's got 8 pending changes.
I thought this was acting okay, but I didn't check test the smoke detectors for a while.
Then, I see the post above, and though updating firmware wasn't a bad idea.
Oy.
I forgot which box I put it in.
Sounds like you may have experienced the issue which that the firmware update fixes! Falling off the network. Check the "last activity" a the bottom of the device page, although I think possibly doing a configure might mess with that which I assume you did, to get the pending changes message,
Yeah, I did something, refresh or configure, that put a new date there.
How do I recover?
edit: For something that's smoke detector related, you'd think reliability would be a priority, geesh.
Did you try to power cycle it yet? That would be step 1.
If that does not work I assume you need to pair it again, either try to exclude and include or factory reset it and do a z-wave replace to get it back into the same node. If you try the exclude and it does not remove the device from the hub, the replace would be your best bet to avoid creating a ghost.
I just tried that while you were typing.
That did it; it's synced.
It's now updating.
It could've been off line for months.
Geesh. Another reason to regularly test the smokes.
Get this app, problem solved. I would have been notified within 24hrs if the device did not respond to the hub. My drivers are specifically coded to work well with that app and only post events if the device responds (the only exception is if you press configure).
Does it consume a lot of resources?
I'm trying to avoid as many apps as possible.
Was just going to ask about this... Jeff, one of the reasons I asked about the Refresh thing back up in post 59 was that I remember having issues with my Z55 and Device Activity Check -- DAC kept saying it was offline each check-in.
And based on all this 1.3 release-notes stuff, heck, maybe it was offline that whole time lol... But at the time, I thought it was maybe because doing a device Refresh didn't show anything in the logs.
When you gave me that line 437 tweak, I booted DAC back up and it's all been great since then.
Now I suspect that was all just a coincidence and my Z55 may actually have been offline back then. Who knows I guess.
It only runs a check once a day (at a time you configure), and only takes a few seconds. So I would say it is pretty light. It does not subscribe to any device events so the other 23.9 hours of the day it just sits there doing nothing.
I just use it for a few key things -- my Zen55 here, water leak sensors, and a few of my not-often-used contact sensors. To me, the peace-of-mind provided is well worth whatever resource draw.
Download the Hubitat app
