There’s a field for most Zwave that tells how much it has battery but it’s no use. When Zwave device dies, the battery value just stays the same forever.
Same thing happens when you start HA. Devices that are dead simply don’t show in HA even when they should. (Actually I think HA shows the cached state of device )
Zwave devices all have a field that tells when was the last time device made a real connection. You can see that field in OZWCP. It also contains what kind of connection was made. If the device haven’t yet made the connection, the status shows Cache(something).
Every device should have these fields in HA. Then users can create alerts for dead devices. It would be quite simple, just alert when the last connection was more than hour ago if the polling time is one hour. If you have like 30 devices, it’s not meaningful to check every devices batteries manually. The battery value that devices show is not reliable.