When the thermometer remains idle for 20 seconds, it reverts to stand-by mode and will display the room temperature for 4 hours before shutting off. When it is on stand-by, even if the display stays on visualizing the room temperature, it does not remain active, which means that the consumption stays lower than that of a cell phone when not in use. The device autonomy with new batteries is of about 3 years or 10.000 measurements, depending on use.