Review on AcuRite 00515M Digital Wireless Fridge and Freezer Thermometer with Alarm and Max/Min Temperature - Ideal for Home and Restaurants by Jay Campbell

I took their advice and paid heavily for the recommended lithium ion batteries which should perform better in cooler temperatures . They failed immediately (no signal). I then used standard alkaline batteries and they have worked great ever since. I use them in both of my freezers (instead of the one in the fridge) which go down to -6F and have been working great for months. There is a freezer in my storage room, about fifteen meters from the display case. and the other is in my kitchen just 25 feet from me, but to reach that 25 feet it has to go through a chimney (two rows of brick and metal) and another wall. I really like how the decimal digit is 1/4 the height of useful digits. The decimal is actually useful if you want to make sure the device is working - the signal sent out every minute necessarily reflects a temperature change of at least 0.1 degrees per minute. I found a major flaw with this device that forced me to downgrade my rating to 4 stars. If the signal from the sensor is lost, the displayed temperature will flash. If you change the batteries in this sensor, it will never connect again. You have to reset everything by removing all batteries from the display and both sensors and starting over. This means you have to re-enter the maximum/minimum alarm settings. They have a button on the back to toggle between C/F (how many times do you have to do that?). This button must be remapped to pair the device with the sensors again.