For the readings, I only really care about catching compressor failure within hours, as opposed to say, days, so for a freezer that's normally set to -18, I figure I'll just do something like "alert if temperature remains above -14 for >2 hours." Of my 4 fridges/freezers, only one has auto-defrost, so I guess I'll have to take that into account there.
The YoLink system works great! I was able to spot an issue causing my chest freezer to very slowly increase in temp (roughly -10 to +10 F in a month) and move the contents before losing the food. Across 5 temperature sensors, I've needed to replace batteries on 2 in 16 months.
For the readings, I only really care about catching compressor failure within hours, as opposed to say, days, so for a freezer that's normally set to -18, I figure I'll just do something like "alert if temperature remains above -14 for >2 hours." Of my 4 fridges/freezers, only one has auto-defrost, so I guess I'll have to take that into account there.