Xiaomi WSDCGQ11LM sensor on Zigbee2MQTT 1.16.2 does not show temperature below -25 Celsius

[AndreyOsadchiy]

I

In my region, temperatures were established from -35 to -40 degrees Celsius.

From the Xiaomi WSDCGQ11LM Sensor, I cannot get the temperature below -25 degrees Celsius.
At the same time, I get up-to-date readings of pressure and humidity without any problems, that is, there is a connection with the sensor and it transmits some readings

Debug info

Zigbee2MQTT version: 1.16.2
Adapter hardware: CC2531

[kevincaradant]

What idea to live in Russia also :D. (I'm joking of course)

However, I think that the WSDCGQ11LM is not a good idea for you because it can work at very high temperature (60 degrees) but not very low (only -20). You are lucky that it works until -25 but you will be stick with that :(

On google, I found this: Temperature detection range and accuracy: -20 ℃ ~ + 60 ℃, ± 0.3 ℃.

BTW: Your battery will work only few days, maybe few months at this temp. I can see 2865 ( around of 30% battery level), at this level, you risk to have some issues like bad data or also the device could leave the Zigbee network ect, just for your knowledge about low battery on Xiaomi devices (< 2900mV). This sensor is not very recommended for freezer at -18 degrees (battery life very short) so winter in Russia, don't expect to much from it :p

[AndreyOsadchiy]

The battery is not a problem. If the device transmitted at least some temperature readings below -25, then it would be possible to connect it to batteries located inside the room (for example, 2 AA cells via a pair of wires) or use a CR battery with a temperature range of -40 degrees Celsius ...
In the Russian-language forums on zigbee devices, I saw a mention that it is zigbee2mqtt that filters the sensor data and cuts off readings below -25 degrees Celsius.

Interestingly, when the temperature rises, the battery capacity also returns to normal.

[kevincaradant]

alright maybe there is also an issue with Z2M in this case. I let others investigate ')

[Koenkk]

The min temperature was indeed limited to -25 as sometimes this sensor provided unrealistic values
(e.g. -100). (#798)

I've extended this range now to -65 till +65.

Changes will be available in the latest dev branch in a few hours (https://www.zigbee2mqtt.io/how_tos/how-to-switch-to-dev-branch.html)