If the author is reading this, I did a ctrl-f in your writeup for "battery" and "life" and didn't find anything specific about how long the batteries on these last. Can you elaborate a bit more on the battery types in use and lifespan? Charging? Since use lithium? 18650? CR2032 or CR2477 size coin cells? Any other details would be very interesting to read.

My biggest barrier to doing something like thins in my home automation setups is that I already have an extensive schedule of things that need periodic disposable battery changes (like CR2477 cells in zigbee humidity/temperature sensors), and I'm really hesitant to add even more into my house. In addition to things like battery-backed smoke detectors in every bedroom, etc, which need periodic 9V replacements on a schedule.

In fact I've started looking at going the opposite direction, where I can run a cat5e cable from my utility room, down and across the ceiling of my basement, and come up in a location where I can install an 802.3af to arbitrary DC voltage DC-DC converter (3.3, 5VDC, 12VDC out, or similar) as a PoE splitter, to make some of these things not dependent on batteries. Same idea as how you can find 9V or AA battery to direct DC wiring "dummy battery" battery eliminators now. Obviously such an approach wouldn't work for garbage bins but that's how much I am trying to eliminate having dozens of batteries to replace, as they're already all over the place with window and door sensors.

What hardware do you recommend for 802.3af to arbitrary DC power? Granular configuration and remote monitoring are considerations in my use cases.