Witch temp/hum sensor is best to use for battery powered sensors?

[Cliff Karlsson]

I know there are a lot of different temp/hum sensors but witch kind is best to use in a battery powered sensor?

[AWI]

@Cliff-Karlsson use an i2C model BME280/Si7021/ SHT21/ HTU21. These work on low voltages and consume minimal. You can find boards with or without voltage regulator and/or pull-up's on Ali. Take a look at a great study which compares many of the sensors available.

[bjacobse]

I use HTU21 without power regulator. directly battery operated with 2 pcs AA batteries/elements, have been working for a few months now.
Just set sleep to maybe 5 min and do reading, if reading = old reading goto sleep again. else send reading to controller.
This saves your battery usage

[chrille]

@AWI I fully agree! The AM2302 (aka DHT-22) does not work, when the supply drops slightly below 3.3V, while the AM2321works at much lower voltage. I have used the AM2321 for more than 6 months to monitor my greenhouse