SwitchBot IP65 Indoor Outdoor Hygrometer Thermometer Wireless, 394ft Bluetooth Range, Refrigerator Thermometer, Dewpoint/VPD/Absolute Humidity Sensor, Free Data Storage Export, 2 Years Battery Life

I purchased this to track the temperature in a portable cooler while multi-day camping in 80+F weather. I'm using a Bodega battery powered cooler that reports its temperature on its control panel. Since the cooler's temperature sensor must be inside a cooler wall, I wanted to know what temperature the food at the top middle of the cooler was maintaining while camping.In testing the SwitchBot at the bottom of the cooler, its measured temperature agreed with the cooler's measurement after a long equilibration period of 1hr as the thermometer adjusted from 79F to 32F. The cool down time was measured from data recorded in the SwitchBot app. Overnight measurements averaged 32F in a range from 30-34F in perfect agreement with my expectation and the 32F set on the Bodega cooler.The SwitchBot app has a logging function for tracking temperature changes. The thermometer stores measurements until the app connects and downloads the stored data. It is not necessary stay connected to the bluetooth to track recent temperature history. I'm not sure how long 'recent' is but it seems long enough for my purposes.Overall, the app works well on my iPhone. It connects to BLE quickly and provides displays of up to 31 days. I am satisfied with the purchase for my use.The SwitchBot thermometer also agrees well with two other trusted thermometers at 78F without calibration. When I initially received the thermometer, I thought that the thermometer required calibration of up to 4-6F after a 30 min wait both at room temperature and with the suggested 30 min time. I left it overnight and the next morning noticed that I needed to eliminate that calibration to match my other thermometers. An equilibration time of 30 minutes might be appropriate for small changes in temperature, but a much longer equilibration is required for large changes. My thermometer does not require calibration.

These feel really great, especially for the price.The packaging is very well thought out, pull tabs everywhere you need them, etc. The actual build quality also seems fine, the shells feel robust and the battery cover has a gasket to keep moisture at bay. Batteries are included and pre-installed, just pull the little tab to turn it on.Functionality wise, Home Assistant will pick these up without any additional work as long as you have bluetooth enabled, so no need for hubs or apps.They expose three sensors, temperature, humidity, and battery. The listing shows stuff like dew point and VPD but these are just calculated, there's no special sauce on the device itself. The update rate is 4s, but the device has a decent amount of thermal mass so the measurements are slow to react to fast changes. This is normal for this class of sensor, but noting it in case someone wanted to use it for more precise stuff. I threw a sensor in my refrigerator and it dropped at around 10F/5m, to give you a sense of the reaction time.

Update: They are currently fixing the app. Will update to final rating after all is fixed. The Bluetooth data loading is still slow, but it won’t fail in background anymore and delete all data. Graph scrolling is still slow, since they scroll the whole graph, not just the marker, like Govee. Not sure how they will fix that.Original:App is wayyy slower compared to Govee. Scrolling graph is jumpy and not smooth. Downloading weeks of data over Bluetooth frequently fails and archives disappear randomly.

UPDATE: SwitchBot reached out. They honored the warranty and shipped me out a replacement quickly. I would recommend they update their website with the detail that they will warranty items bought through their official Amazon store. Solid customer support!!Generally these work well and seem accurate. They are easy to setup and use either in their app or as I have them setup in Home Assistant. I had 1 out of 6 completely die in less than a year. It was a unit used indoor and never moved, so hardly a tough service environment. New batteries and no light and can't reset it. Just dead.Battery life is strong as long as you have a bluetooth receiver/BLE proxy very close to them. Otherwise, life is about 8 months, which is reasonable. Get rechargeable NiMH AAAs with a charger on Amazon for $20 and you'll be in batteries for these for life.