ST multi sensor in freezer

I read from several threads here that people seem to be having success with putting the smartthings multi sensors inside fridge/freezer so I bought one and placed it inside my freezer which is running at about 0F. It seemed to be working initially. Open/Close is reported correctly. Temperature was slowly declining tho it seems to need a long time to soak. It was in the freezer for three hours and still not at temperature. I have a thermopeanut in the same freezer stabilized in less than half an hour.

What’s the most concerning is that the battery readout dropped from 100% to 50% in three hours. I took the sensor out and let it back to room temp then took the battery out and reinserted it back in and it’s back to 100%

I checked that the cr2450 is rated down to -30C so it shouldn’t be an issue. Has anyone seen issue with this? I am not sure if I have a busted sensor or it’s something normal and wonder if I can safely ignore the battery readout. Thanks

I had one in a refrigerator for over a year no problem but my freezer is 0deg farenheit and I thought that would be pushing it. In the fridge it was very accurate. I had a professional fridge thermometer next to it nd they always agreed.

Pretty normal for a battery and I wouldn’t worry about it. Although this isn’t specific to the CR batteries it is about batteries:

“A battery that provides 100 percent capacity at 27°C (80°F) will typically deliver only 50 percent at –18°C (0°F). The momentary capacity-decrease differs with battery chemistry.”

I personally have mine in the fridge and I noticed the battery dropped after a couple hours but its been in ther working fine for 6 months now. Haven’t tried the freezer…figure if the fridge fails the freezer will too.

i had exactly same so its not just you, not sure where you are in the world but in the Uk frozen food is recomended safe at -17 ( 1.4f ) with probe between 2 frozen packages

Our feezer seemed to be over freezing so i put the St multi sensor between 2 packets of frozen things in the freezer, within no time the battery fell away to 18%. it worked and reported temps but after a couple of days i took it out, reset it and it went back to 100%, the sensor is now on front door, front light duties and battery is at 90% with a balmy 6deg (42.8f )

Thanks for all the replies. I put it back in the freezer and it’s been over a day. The battery status dropped to 30% in the first 10 hours then stabilized. The temperature reading and open/close status still functional at the moment.