homeassistant @lemmy.world GreatAlbatross @feddit.uk 3w ago

Long-term feedback: SONOFF SNZB-02D humidity/temperature sensor

I thought I'd pop this up here, as I've now had mine almost a year.

I've had sonoff zigbee sensors for a while, and wanted to try this slightly updated one with a display.
To cut a long story short:

It works
It communicates and pairs with HA ZHA integration out of the box.
I've not had any issues at all since I bought it.
The display is clear
The bracket sticks to the wall, then the sensor magnets into the bracket. The sensor also has a fold-out stand for placing on a surface.
After almost 1 year on the included battery, it's showing 60%
I paid about £12, they're now around £14

Battery use should obviously be taken with a pinch of salt, but I would not be surprised if it's still trucking after 2 years.

Accuracy is fine for consumer level gear

I also discovered (after updating to HA latest) that temperature and humidity thresholds can be set on the device.
And that it will show symbols on the display when these limits are breached. By default, it shows a snowflake when it's under 19'C.

So, yeah. For areas where people are likely to want to check the temperature quickly, they're neat little dooberies.

34 comments

I use them in my terrariums, it's nice to have the display when you're there as well as history in HA
I've been running three of these for about the same length of time - two things surprised me, but both are documented in their manual. First, the working temperature is -9.9℃-60℃/14℉-140℉, so if you plan to use one in an environment colder than ~10℃, the readout will flatline. Second, they use a CR2450 battery, which is a little more difficult to find where I live than a CR2032.

Neither of these are criticisms, just things I wish I had noticed sooner.
- CR2450 has nearly 3x the capacity of the CR2032 (620mAh vs 225mAh) so the benefit of using it is that you'll have to replace it far less frequently.
  
  But there is a difference in physical size that one might want to double check.
This is actually really helpful. I have a cheap one from Tuya, that also has a display, but the battery is empty after like 2 weeks and I don't wanna keep constantly changing it, so it's always off. This sounds like a great replacement.
- I only go Tuya if there is absolutely no Zigbee alternative. I've got curtain bots on Tuya which were fine when it was one curtain but now they barely respond to automations anymore.
  
  And you could probably replace whatever Tuya does with Esp32;)
  
  I only buy ZigBee devices from Tuya, they do that too
  
  Tuya make Zigbee products too... They're just not good Zigbee products. I don't think they're officially Zigbee certified and have some weird behaviour, similar to some of the older generation of Aqara devices (their newer ones are fine though)
- We have this in the living room. It uses 3 AAA batteries and they're still 90% after several months.
  
  https://a.aliexpress.com/_mq6wiRv
  
  The one I have uses only one of those little puck batteries (or whatever they're called)
  
  Would you say they're accurate enough? Ive been thinking about getting something like this especially now that the temperature varies so much here in the UK.
- I keep wondering if I should open a little non-profit shop, specialising in "cheap home assistant stuff that isn't awful, that I've tested".
  Then I remember the absolute chaos involved in running a shop...
I've thought about getting the third reality ones that do the exact same thing pretty much.
- I love my 3r stuff.
  
  I've had one of their smart plugs for about two months now and I'm very happy with it so far.
I also have several of these as a replacement for some Tuya sensors I added a power supply to because they ate through batteries. The Sonoff not only has a way better battery life, they also feel and look nicer and the readings are far better. The Tuya sensors were all off by several degrees and the Sonoff are way closer to the real temperature. I cannot recommend them enough.
If you want accurate humidity I would highly suggest getting a Sensiron SHT45 and attaching it to an Esp32 with Esphome. These things are fine if you just wanna prevent molds in your apartment, but absolutely useless for anything middle than that
- I'm currently eyeing up an Airgradient One, which uses the SHT40.
  Unfortunately, I don't have enough tinkering time at the moment to roll out much more kit.
  
  In honesty, I use the relative humidity readings as more of a "it's dry" "It's OK" "it's moist", than expecting any sort of accuracy!
  I've even considered mapping percentage ranges to "moist, normal, dry" in HA.
  
  I mean, for most applications +-5% accuracy is perfectly fine. I use them to monitor humidity inside my grow tents, so I need very high precision for VPD calculation
I replaced the battery on mine in under a year despite it reporting 92% or something like that... Using with Hubitat Elevation with the default update rates or slower. Very disappointed in the battery life otherwise, a great sensor
I'm waiting for the Ikea Timmerflotte. Any day now...

34 comments