These are the ones I got, just because they are only $9 each, with a display as well. Each one has 2x AAA battery, so I'd expect they'll last quite a while. HA also reports on battery level - https://www.amazon.com/dp/B0872X4H4J
They are bluetooth, but I already had an ESP32 for other sensors. Seems to work great w/ Home Assistant / ESPHome so far!