Frequently asked questions

• Will it survive winter on an open balcony?

  Yes — the official working range reaches down to −20 °C. Near that limit the maker is upfront: deviation may widen to ±0.7 °C, battery capacity sags and the screen can ghost on refresh; as the air warms, the display returns to normal.
• What exactly does the IP65 case put up with — showers, rain, irrigation spray?

  Water jets from any direction: the official test uses a 6.3 mm nozzle at 12.5 litres per minute. Shower spray, rain under a canopy and greenhouse mist are all normal duty. Submersion is off the table — for liquids SONOFF makes the SNZB-02LD probe.
• How often do the numbers update and how accurate are they?

  The screen refreshes every 5 seconds; rated accuracy is ±0.2 °C and ±2% RH. Data reaches the app the moment a threshold is crossed, otherwise at least hourly; both the interval and the thresholds are adjustable in eWeLink, which also offers calibration.
• Where should it hang in the yard to read true?

  In the shade: under the eaves, a canopy or on a north-facing wall — in direct sun any thermometer overstates. Out of the box you get the rope through the loop and the magnetic back for metal; the maker itself pictures it under the eaves and in an RV.
• Which battery does it run on and what does frost do to it?

  A 3 V CR2477 coin cell, pre-installed — just pull the insulation tab. On default reporting it lasts over two years. In hard frost the capacity drops and, as the maker warns, never fully recovers — keep a spare for an outdoor unit.
• What does it pair with — I run Home Assistant and an Echo speaker?

  Both. The official list: SONOFF ZBBridge-P/U, NSPanel Pro, iHost and the ZBDongle-E/P sticks — the route into Home Assistant via ZHA or Zigbee2MQTT. Echo Plus 2nd gen, Echo 4th gen and Echo Show 2nd gen pick up temperature, though Amazon's hub passes no humidity. Philips Hue and FritzBox gateways are not supported.
• Will I get an alert if the greenhouse cools overnight?

  Yes: set temperature and humidity thresholds in eWeLink, a push arrives when one is crossed, and a scene can start a heater through a smart plug — the +5 °C example comes from the maker itself. Any Zigbee 3.0 hub from the compatibility list will do.