Long range temperture sensors don't archieve the advertised battery lifetime


We are using 30 IoT Long Range Wireless Temperature Humidity Sensors.

We’ve deployed them at a customer and were happy with the data we are getting. Unfortunately a few of the sensors failed quite early. In less than 16 days the sensors died. We thought it might be an error on our side so I did an experiment at my home.

I set up 5 sensors all configured to:
Interval: 30 sec
retry: 3 times
power: 4

On 7 Dec I installed them around the house. I configured them with 12v power and put in new batteries:
mignon 6106
FR14505 1.5v

Today 15-dec-2022 I’ve checked on them. I turned all of them off and let them warm up. One of the sensors failed already.

I’ve measured all the sensor’s bat voltages and the broken sensor’s batteries were 0.689V and 0.426V measured using a Brymen BM235. The measurement was done when the sensor itself was reporting 15 degrees Celsius when I connected it to a power supply.

I think this is not supposed to happen and I think it is related to the sensors. I’ve put new batteries in the failed sensor to see if it would fail early again.

With two other sensors, we have different problems. Those sensors can not be found with the gateway at all. As requested on the forum I’ve tried to flash the rf modules with a profile but they are not recognized when I put them in the gateway. Others sensors are recognized when I try the same.

I hope you can help me with these problems and if necessary replace the broken sensors.

Hope to find a solution!

I think scheduling a call and looking at your setup will be best. We now have close to a hundred thousand of these units in the field and didn’t encounter such an issue.
I can be reached at bhaskar@ncd.io