Nest 3rd thermostat low battery

[Abe2]

I been having low battery issues for a while. I charged the thermostat for several days via usb and the AC would work for 2 hours and the thermostat would shut off. 

I bought a nest adapter and installed it to the furnace and still same issue.

I bought a c wire and plugged it into nest (one wire to c and one wire to RC), it was powered on but no AC. Then I removed from RC, AC works but power was draining.

I'm not sure what to do next.

[moralesvicente]

Hello Abe2, 

Thanks for posting here in the community forum. I’m sorry to know that your Nest Learning Thermostat 3rd Gen is showing a low battery. Don’t worry; it's a pleasure to assist you. 

I am grateful for your time and effort in completing these troubleshooting steps described in the post, so let’s explore more options.

Help me out by answering the following questions to expedite assistance:

• Could you tell me what the battery level of your thermostat is? Go to settings, technical information, then power 
• When did the trouble first occur? 

In the meantime 

• Double-check if you have installed the Nest power connector correctly. If you have concerns, take a look at this video: How to Install a Nest Power Connector for Your Nest Thermostat. 
• If you are using a C wire connected to your thermostat, please make sure that this wire is connected directly to your HVAC system and then plug it into the wired configuration of your thermostat. A different way to connect a C wire is not recommended with this unit. 

To get additional information, check out this article: Learn about the common or C wire.

Keep me posted so I can provide you with more assistance.

Best regards,

Daniel 

[Abe2]

I had a technician come in and installed a c wire for me in my house. He said that NEST thermostats encounter low battery issues and require a c wire connection to have a dedicated constant power because when using AC and wifi it will draw more power. 

[moralesvicente]

Hi Abe2,

Thank you for keeping me updated.

I understand that a technician installed a C wire to your thermostat to ensure proper functioning. To expedite assistance, please let me know if the Nest thermostat is still losing power. If so, please tell me what the battery level is. You can find this information by going to Settings, Tech Info, and then selecting Power.

When does this behavior first occur?

Please feel free to share any additional details that you think might be relevant.

Best Regards, 

Daniel

[Abe2]

Yes the battery continues to lose power. After charging it via usb for 3 days, it would start at 3.6 volts, then it would drop to around 3.4 volts. Before, when I didn't have a c wire, the thermostat would shut down and I would have to charge it.

Since I have a c wire now, the thermostat doesn't shut down anymore and doesn't need to rely on the NEST battery, however, the thermostat always shows low battery and can't connect to wifi. I'm ok with this as long as I have AC in the house.

[moralesvicente]

HI Abe2, 
 
I’m sorry to hear that the trouble is still not resolved. So don't worry. 
 
To continue assisting you. Please provide the necessary information on this form. A member of our senior support team will follow up with you by email. 
 
Regards,
Daniel