Battery issues

[PogoBrian]

Hi guys!

We are having battery issues on our Nest Thermostat - after a year and a half of use with no problems, the battery died. I popped off the unit and charged with the USB port, which worked for a day or two, then died again. 

Is there any way to swap out the battery inside? Or is it possibly a wiring problem between the thermostat and the switch on the heating/cooling unit? If so, why would that suddenly be an issue after nearly two years of use?

Any ideas? Thanks!

[MelbaDT]

Hey PogoBrian, 

Thanks for reaching out and sorry for the delay. 

I'm afraid that if you have the Nest Thermostat E or the Nest Learning Thermostat, the internal batteries are not replaceable. And yes, a thermostat that drains battery faster than expected means that there is something wrong with the wires. It means that it is not getting enough power from your HVAC system so it eats up it's internal battery. Do you happen to have a C wire from your HVAC to your Nest thermostat?

Best, 

Melba

[PogoBrian]

Thanks Melba - that’s kinda what I figured, as when I switch the Nest Thermostat from another part of the house (a separate system) onto the troubled Nest’s base, it also loses charge. And the original Nest when mounted on the other base, charges and holds charge fine.

The Nest in question functioned properly and charged properly for at least a year, and nothing has changed with the wiring… why would it suddenly not provide a charge? 

There is a C wire, but I guess it stopped providing a charge for some mysterious reason…

[MelbaDT]

Hey there, 

I understand how you feel and that's a valid question. I also appreciate the fact that you've tried swapping the thermostat to the working one. 

Overtime, wires degrade and terminals loosen up like any other electrical and electronic devices. That's why it is always best to have conduct maintenance on them from time to time. Please reach to an HVAC technician or a a local pro for better assistance.

Best, 

Melba

[MelbaDT]

Hey there, 

Checking back in — how's it going? Have you had the chance to have your HVAC system checked by a professional already?

Best, 

Melba

[PogoBrian]

No not yet… it cooled off in the meantime, so it got bumped down the honey do list 😂

[MelbaDT]

Hey PogoBrian, 

Understood — keep us posted then as soon as a technician was able to check on it. 

Best, 

Melba

[PogoBrian]

Hi Melba - I have another question:

Under the technical info menu and “charge”, the numbers that show up all seem to be in the optimal range, specifically the “lin” value is at 200. Doesn’t this mean that there is sufficient power to the unit and that it should be charging?

Thanks! Brian

[MelbaDT]

Hey there, 

IIN value of 200 just means that a C wire is installed. I hope this answers your question. 

Best, 

Melba

[MelbaDT]

Hey there, 

I hope I was able to answer your last question. Let us know if you have more in mind. 

Best, 

Melba

[MelbaDT]

Hi, 

We haven't heard from you in a while so we'll be locking this thread if there is no update within the day. If you have any new issues, updates or just a discussion topic, feel free to start a new thread in the Community.

Best, 

Melba