One automation for each battery was getting crazy. A temperature sensor in most rooms, motion detectors and a handful of door/window sensors. This blueprint creates an automation that manages all batteries dynamically. Really is amazing.
What blueprints do find useful?
https://community.home-assistant.io/t/low-battery-notifications-actions/653754
I’m not quite sure how reliable these battery indicators are. I have a thirdreality moisture sensor at 0% for a week now. Still the original battery too, so you’d think that was actually properly calibrated. 😆
So I just go with the unavailable and deal with it then. Though the notification automation that I made for that did break at some point. I need to figure that one out again.