Sonoff SNZB-02 temp/humidity sensor disconnects

Since moving my wifi accesss point to wifi ch.11 yesterday (to get it away from the Zigbee Bridge on Zigbee ch.11), another sensor disconnected overnight.
So, the disconnects don’t appear connected with wifi interference.
Temp2 disconnected 4am 12-20-2020

After removing this Temp2 sensor from HA, and rescanning for it, it got re-added.
Look at the insane drop in battery power (Voltage)!
Temp2 shows wild voltage swings 12-20-2020

How does a micro power sensor go from 100% down to 40%, overnight???
Can we trust the power metering in these devices?
When I remove the batteries at test them with the appropriate 3V lithium setting on the battery tester, they show they have a charge in the green, good range!

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I’ve been using a couple of these for a couple of weeks now using a cheap CC2531 adapter on Zigbee2MQTT with no issues whatsoever, both still report 100% battery too

I know it’s not much help but thought the information may be useful in some way…

Last night I put a new battery into the sensor I am calling Temp2.
I rescanned (without removing it from the HA devices list) and it showed 100% battery.

When I checked it this morning, I discovered that it didn’t stay connected very long!
There were no more reports from the Temp2 sensor after the re-scan step.

So, I did another device re-scan (without removing it from the HA devices list) and it reconnected with a battery percentage of 47%! WHAT?? It’s a new battery!!
image (1)

Next, I tried removing the Temp2 device from the HA devices list and then doing a re-scan to add it back to the HA database. After doing that, the battery was reported at 100% again.
image (2)

There’s something significant that happens when you remove the device from the HA database, and re-add it!
Results like this point to a software/firmware problem rather than a hardware problem.

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I’m running an HA x86_64 OVA virtual machine in VMware.
I’ve seen some python zigby-related error messages in the HA log
zigpy log errors

From the Terminal in the HA interface, I’m trying to locate python, zigpy and bellows.
They are supposed to be in the following locations but are NOT there!
/usr/local/lib/python3.8/
/usr/local/lib/python3.8/site-packages/zigpy/
/usr/local/lib/python3.8/site-packages/bellows/

Where are they??

I’ve had good success with a couple of the Sonoff SNZB-02 sensors, but a third one is not measuring the temperature (just sends 0). They’re so cheap I hardly care. I’ve got a slightly more expensive AQara device arriving soon which does air pressure as well, I wonder if that will prove more reliable.

Update: The Sonoff sensor is now working properly after a couple of resets. The AQara sensor - WSDCGQ11M - arrived, and is working well. It’s a physically smaller, neater looking unit than the Sonoff (and it comes in a much larger box), with a smaller capacity battery (CR2032 vs CR 2450). deCONZ/Phoscon recognises it as a Xiaomi multi-sensor, so Home Assistant is happy with it.

I updated Home Assistant to the latest version (2020.12.2) on Dec.24, and the disconnections of the SNZB-02 sensors stopped.
I’m crossing my fingers that the the update was the fix!
I will keep watching for disconnections…

I don’t think so. I have two SNZB 02 and the latest version of HA, and one disconnect earlier this week, the other disconnected yesterday…
I’m waiting to receive my Conbee II stick to try with Deconz or Zigbee2Mqtt instead of ZHA with the Sonoff ZBBridge

DOH! I had a disconnection of my Temp2 sensor overnight.
Yesterday, I was altering the configuration of my Zigbee network by adding a Sonoff S31 Zigbee outlet, with the desire to have it be a repeater for the Temp2 sensor.

After pairing the Sonoff S31 outlet with the Sonoff Zigbee Bridge, it didn’t appear to be automatically providing repeater support for the Temp2 sensor. ZHA_MAP diagrams were my evidence of this.
image

So, I tried to manually pair the S31 with the Temp2 sensor, and it appeared to be functioning as a repeater with a strong signal connection between the S31 and Temp2.
S31 repeating Temp sensor

But, this morning, the Temp2 sensor was disconnected AGAIN, so I don’t know what went wrong.
It sure appears that Zigbee just barely works. :roll_eyes:

Having the same issues with a SNZB-02 and the sonoff zigbee bridge flashed with tasmota.
It happens every few days to once in like 2 weeks. I’m not sure how zigbee works, but i’d think that if one of the reports by the temp sensor gets missed by the gateway because some interferance or range issue, it would be able to pick up later reports again. It seems that once it fails, it doesn’t get any reports from then sensor at all anymore, even when you place the sensor next to the zigbee bridge.
This seems weird to me as they don’t have a constant connection, and it’s not like the connection has been dropped or someting.

EDIT: I also have a lidl led bulb that is connected to the sonoff zigbee bridge, and this never loses the connection, even when the power to the bulb gets cut, and later gets powered on again it reconencts to the gateway just fine.

2 weeks ago I added an IKEA TRADFRI repeater to the ZB network and within 5 minutes it paired itself with temperature sensors and started repeating their signals back to the Sonoff Zigbee Bridge!

The whole ZB newtork performance improved after adding just 1 of the TRADFRI repeaters!
Even the Sonoff S31 started automatically pairing itself with nearby temperature sensors shortly after adding the TRADFRI repeater.
Until the TRADFRI showed up, the S31 had been acting like a slug - not automatically pairing and repeating. To anthropomorphize, it’s like the S31 saw there was competition, and so it started behaving like it should have, all along! :laughing:

The other benefit I’ve observed, none of the Sonoff temperature sensors have disconnected since the addition of a TRADFRI repeater!

I just added another TRADFRI repeater this morning, and I’m watching hour to hour as temperature sensors re-pair themselves with the new TRADFRI.

Hi everyone,
I am having the same issue with my multi-sensor Sonoff SNZB-02 and Conbee 2 device. The Conbee 2 is already working well with another device (Aquara door sensor) but after I paired the Sonoff sensor with Phoscon, it would actually work during only a few hours and after that, both the temperature and humidity would remain constant even though I know they aren’t.
Going back to Phoscon where the device is listed, and I can read the last update is from several days ago. It’s like no temp/humidity data has been pulled since that time, event through it should have.
Any idea what’s the problem?
Can it be installed with a different method than the deconz addon in HA?
Thank you

I have the same issue with a Conbee 2 & Zigbee2MQTT…
And also with the SNZB-04 devices, but less often.

I did a video on the SNZB-04 and mentioned in it that I bought three. One drains the battery in a matter of days, one just stops responding (light doesn’t flash opening the door) and so I have to re-pair it. Am dropping the Sonoff devices and replacing with Aqara ones. I was running Conbee II with deConz, tried with Conbee II and ZHA, now using Sonoff Bridge with Tasmota and ZHA, still getting issues with the Sonoff SNZB-04. My Aqara sensors have been reliable so will switch from Sonoff to Aqara.

As an FYI, I just learned of a January 2021 update to the zigbee radio firmware for the Sonoff Zigbee Bridge. The update version is ncp-uart-sw_6.7.8.
see Tasmota/tools/fw_SonoffZigbeeBridge_ezsp at development · arendst/Tasmota · GitHub

This update fixes battery drain problems with IKEA Zigbee devices.
I wonder if it will fix the disconnection of the Sonoff SNZB-02 temperature sensors?

Some caveats of the update process are mentioned in this thread.
The key to the update is to change the Module type to 75.

All I did was change the Module type to (75), in the Tasmota Configuration page, and then was able to upload the new file without upload errors.
After the update, you then need to switch the Configuration back to the custom configuration (0) so it will function as a Zigbee bridge for ZHA, again.
Type 75

Thanks for the details. My Sonoff had already been updated with the 6.7.8 radio firmware and the battery issues were still hit or miss along with a few other ‘quirks’.

I bought one of the Tube Coordinators with ethernet on it and received it today and re-paired all my devices. A few were a PITA about getting on the network and I went back and finally deleted my zigbee.db and started again fresh. Things seemed to go better after that.

Have one device that keeps jumping off the network and I need to work through that issue still. I have plenty of routers in the network and the mesh is looking pretty good.

We’ll see how this goes - the Tube hardware ended up costing about 3 times as much as the Sonoff, but if it solves the problem, I guess it is worth it. The Tradfri remotes seem to pose a bit of a challenge to ZHA once in a while.

I’ve also had a bunch of issues with the Sonoff PIR’s and Temp sensors (Sonoff SNZB-02)

Dropping out, consuming batteries in a month and have always had my Conbee II on an extended USB cable, conversely the Aqaras have been fantastic. The Sonoff Windw/Door sensors have also been pretty good overall 1 out of 6 failing completely.

My advice stay away from them, they’re cheap and nasty.

Not wanting to necro this thread but I wanted to chime in on my experience as well. I have the same issues with the Sonoff SNZB-02 together with the Sonoff Zigbee 3.0 USB Dongle Plus V2. No battery drain or anything but just random disconnects where I have to fully delete and pair the sensor again in order to make it work.

I got a couple of window sensors as well, those work like a charm. But the temperature sensor is just unreliable.

I have same issue with my SNZB-02. It just work some time and after just stuck at last value of temp and hum. I try to use it with zigbee2mqtt and tuya but same behavior. Most tragic is that I bought a lot 20 devices and they work all in the same way :expressionless: .

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I also have/had issues with SNZB-02 + Sonoff Zigbee Bridge (though curiously not in another setup with the Sonoff USB Dongle).
The sensor would lose connection with the bridge every day or so and need repairing.

Then I replaced the CR2450 battery with two AA batteries using this sonoff temperature sensor battery hack and since then the sensor kept its connection - fingers crossed it stays that way.

Maybe the lower internal resistance of the AA batteries helped the matter…