You might try one of these suggestions. Using Z-Wave JS ping to detect dead battery powered nodes - #2 by freshcoast
The wake-up interval defines how often a battery device “checks in with the hub”. That wake up is reflected in the Node Status sensor. Are you sure it never changes? When it does change it’s usually a second or less. Device wake-up can be configured from hours to days. I do have a door sensor (Hank) that doesn’t wake up.
If your device never wakes up, then you’ll have to rely on any entity that you expect to update sometime. For example, for the door sensor if you know the door should be opened at certain times each day, you could make an assumption based on that time, e.g. door hasn’t been opened for X hours. You could use the last_updated attribute of the entity, which should change when the door is opened, or just trigger off the event.
None of the solutions are fool proof. If HA is offline when the sensor is supposed to update, you won’t know and it might look like it was “offline” based on the criteria you’ve set.