Low battery disables Matter completely. Why?

[Treyus30]

Got Matter set up a few weeks ago on my Nest Thermostat. Batteries were changed about a week before that for a low battery message. Yesterday I noticed that it said "very low battery" again, which I thought was odd since I just replaced them. No matter (haha), I thought, just a quirk, doesn't affect operation. Today I realized my Home Assistant was not connecting to it anymore and the Matter config is disabled on the Nest itself due to the low battery issue.

This seems absurd.. The unit has power. If this will not be fixed through a firmware update, I'm ready to make a little AC-DC 3volt circuit to fool it into thinking there's a battery.

[AxelD]

Hi Treyus30,

Thanks for posting in the community! Sorry to hear that Matter got disconnected form your Nest Thermostat due low battery. No worries, help is here! I'd like to ask you a few question to gather more information:

1. What type of Nest thermostat do you have? 
2. Is there a wiring report or error message on your thermostat and/or app?
3. Do you see a blinking LED light? If so, is it red or green?
4. Were there any modifications to the internet configuration (for example: added extenders)?

Keep me posted.

Regards,

Axel. 

[Treyus30]

1. Nest Thermostat (non learning)

2. No wiring errors. Voltage is around 39V.

3. No blinking.

4. No changes to internet config after setting up the Matter connection.

I did notice the guide at https://support.google.com/googlenest/answer/9240096/#Matter does state this may be an intended feature (battery low may disconnect Matter). Why this is is beyond me. An oversight? A method of corporate control? Poor decision making?

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Troubleshoot Matter issues

These steps cover the following help codes: M26

A M26 error means that your Nest Thermostat can't connect to a 3rd party app that supports Matter-enabled devices. There are a few reasons this might have happened.

• Your thermostat's battery is too low
• The Wi-Fi is unavailable
• Your thermostat wasn't first added to the Google Home app
• Your thermostat is already paired to the maximum number of 3rd party apps
• Your thermostat shows a "Matter linking is currently unavailable" messages"

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I threw new AAA batteries in and now it's happy to connect again, but can't. Says Matter server is unavailable (it's not as all my other 9 Matter devices are working properly).

[Treyus30]

Another update: the new batteries say "very low" after a restart again. I threw in yet another new pair, and it still says very low, battery voltage on the Nest says 2.5volts. The batteries test above 1.5V each on my multimeter. Seems my Nest is defective in addition to the Matter disablement issue.

[AxelD]

Hi Treyus30,

Thanks for your reply!  I appreciate the details you provided. If you've replaced the batteries and the device still indicates a low battery, it might be malfunctioning.  Please fill out this form, and an agent will contact you as soon as possible with further troubleshooting steps.

Regards,

Axel.