Will the Nest gen-3 run without a battery?

[OGoldman]

My Nest thermostat will not operate, stuck in a continuous "need to restart" loop that's alleged to be because of a dead battery.

My system has a C wire, and I measured the voltage across it at 26V. I removed the battery pack from the thermostat. Every replacement I've seen has bad reviews, I don't like the fire risk of a no-name battery in the wall.

Will this thing run without the battery? Is there a hack to allow it to, or to allow the use of regular batteries by running a wire into the Nest through a drilled hole? I have the connector off the battery and can solder to it. Would the 4.5 V from three AAs damage the unit?

[zoeuvre]

Hi OGoldman, 

Yikes! The Nest Learning Thermostat will not work without its built-in battery, and its built-in battery is not recommended to be removed. Regarding the dead battery issue of your Nest Learning Thermostat, this could be caused by an unstable Wi-Fi connection, interferences, or power-sharing issues that lead to the thermostat's low battery. With this, a few questions: 

1. Are you located in North America or Europe? 
2. When did the issue first occur?
3. What is the make and model of your heating, ventilation, and air conditioning (HVAC) equipment?
4. Are the power breakers on, and do you receive power to your home?
5. Is the thermostat's display seated properly?
6. Are all the wires of your thermostat seated firmly in its terminals (with no loose or exposed wires)?
7. Does the thermostat charge with a USB cable?

I'll look forward to your response. 

Best,

Zoe

[Darchibald73]

Zoe, hi there,

I saw this post and have the same symptoms as OGoldman. Would you be able to help support me in this 'identical'  problem?

1. Are you located in North America or Europe? (North America, Harlingen Texas)
2. When did the issue first occur? (5 day ago, on Tuesday April 2)
3. What is the make and model of your heating, ventilation, and air conditioning (HVAC) equipment?Bryant, forced air heat pump)
4. Are the power breakers on, and do you receive power to your home? (Yes all breakers are on and there is power to all, I have C wire connected)
5. Is the thermostat's display seated properly?  (I assume Yes, because it functions properly, just not with the wi-fi, because battery is low)
6. Are all the wires of your thermostat seated firmly in its terminals (with no loose or exposed wires)? (yes I double checked their security and fully seated)
7. Does the thermostat charge with a USB cable? No / Yes (there is no indicator light saying it is charging, however - after 3 hours on the charger - when I replace and check the power settings it shows 3.8 after charging whereas before it was  3.2V) but charge only lasts a couple hours and is not sufficient to connect to wi-fi.

[OGoldman]

Thanks for the reply.

North America

It finally failed last week.

AC is a Carrier NXA648GKA100. Furnace is a York TG9S080C16MP11A. Both irrelevant.

All power is on.

The Nest was seated properly.

The wires are all perfectly secure, and the C wire is delivering 26 volts (I checked it).

It does not charge with a USB cable.

This is a well-known situation that is widely discussed online. The Nest thermostat is a disposable product, according to Google (from https://support.google.com/googlenest/answer/10119271#zippy=%2Chow-to-replace-the-batteries 😞

Note: You cannot replace the batteries for the Nest Thermostat E or Nest Learning Thermostat.

Disgraceful.

[sicsacol]

Hi OGoldman,

Thank you for the information. To provide you with better support and gather more details about this issue, please fill out this form, a team will contact you as soon as possible.

Let me know once you're done 

Sincerely, 

Jonathan

[OGoldman]

I did fill out the form and submit it.