Temperature sensor that uses battery and ac power?

What is a good temperature sensor that uses z wave zigbee or something totally local that updates very quickly and can use battery and AC power simultaneously as to avoid power outages or changing batteries (at least often)

Have a look at this solution: GitHub - pvvx/ATC_MiThermometer: Custom firmware for the Xiaomi Thermometers and Telink Flasher
I’m using some Xiaomi Mi Thermometers now in combination with BTHome and Shelly Plugs as BLE proxies.