Dodgy battery level reports from z-wave motion sensors - is this normal?

I have a couple of Z-Wave Fibaro Motion Sensor Gen5 (4-1) and they’ve worked well since about November. one went off line today and I’m confident that the battery needs replacing. Now, whilst this battery has lasted much longer than an Everspring SP103 (which lasts about 3 months in comparison), what I find confusing is that the Fibaro was reporting 81% battery right up to the moment it died. I had seen something similar with the SP103 but had hoped that the newer Fibaro would be more reliable. Unless I’m missing something in the config, the battery level reports don’t seem to be worth anything. Any views?

This is my experience as well, hardly any battery operated device seems to be able to report its battery level as it should regardless of vendor…and it doesn’t seem to be a binding problem, IMHO.

I see the same disappointing behaviour - just yesterday a FGMS001 Motion Sensor went from 100% battery to off-line and dead in about 24h!

Inaccuracy would be understandable if different battery chemistries were involved (e.g. alcaline, NiCd, NiMh, etc) but the 3.3v cells are only one type.

The best mitigation I’ve seen is a rule to warn of lost devices by adding all battery devices to a group and monitoring when they last communicated.

ISTR a forum post, or a design pattern.

I Have bluetooth devices, and on a cold night will do almost exactly the same thing. Will hit about 80% then just go off line.

I did have a rule that would warn me and send a notification, but I haven’t migration it to my new system. Was about the only thing I could do about it.