Nest 3rd gen Thermostat low battery issue after several years

[ErnieC6720]

After about 4 years, my NEST is now going to low battery and disconnecting from WiFi.  I can recharge with usb but doesn't seem to be charging on the wall.  Nothing has changed in my home.  Can these rechargeable batteries be replaced?  Could it be something else?  It hasn't happen before.  Maybe once after a power outage but never again.  Any suggestions would be greatly appreciated. 

[lrankine]

Got tired of messing around trying to get the Nest to work.  I've switched over to the Eccobee and am not looking back!

[BanjoBill]

I just purchased 3rd Gen today and am having the same issue...out of the box.  We checked the voltage on R and it is reading above 24 volts. Appears the last software was in October...Anybody have any new info??

[TXRick]

Take it off the wall and make sure you give it a good charge before using it. The AC or Heat might need to run for it to recharge the battery after that depending on your wiring setup.

[BanjoBill]

Thank you!  We'll give that a try

[EdB]

For me is the opposite. Having used AC or heat for 7 days and haven't needed to pull and charge. Was having AC run for 3 hours a day and that was enough to have low power.

[EdwardT]

Hi EdB,

Thanks for letting us know. Please let us know more about this so we could investigate further. Could you answer the questions I posted above?

Thanks,

Edward
 

[korella0707]

Hello I have the same problem. How can I fix my thermostat?

Thanks Ella

[TheTomasN]

I changed my transformer (not that the old one didn’t work) and I had the same issue. Right after some time the thermostat got disconnected for the network. I take it off, fully charge it for over a day and out it back. Still had issues. I am not monitoring it now but I know it get disconnected because I have the nest sensor as well and when battery is low the sensor disconnect. Then the thermostat charge up and good again. It’s like a circle. But the weird part is that I have 2 thermostats (one for each zone) , they both wired the same way but only one have the issue. 

[Scorpio1st]

• Same issue here with third gen nest , worked fine with no C wire for almost 4 years and now the battery won’t charge. I wonder if this is a software issue causing the battery to drain.?

[MichChiro]

Same issue here.  Around 4-5 weeks ago, I noticed our house was getting cold.  The Nest had the small, red light at the top blinking, indicating a low battery.  I charged it via the microUSB port on the back, and it was good for a couple days.  Kept having to charge it over and over again, and it would last progressively fewer hours.  I figured the battery was going bad, so I looked for a replacement.  I found out that Nest batteries aren't for sale (I think they just want you to buy a new thermostat!), but I was able to locate an OEM on eBay.  There are also third-party batteries that supposedly work, but they aren't the same rating.  Changed the battery and had the same issue, except it would last longer than my original battery that was apparently dead.  I ordered and installed a C-wire adapter from Amazon, as my system did not have a C-wire and it wouldn't be easy to fish one from the furnace.  Still getting a 'low battery' error when trying to connect it to wi-fi, but at least it doesn't die now and leave us freezing in the middle of the night!  I may charge it via USB again and see what happens, but I thought it was supposed to charge the battery while installed on the wall?  Like the previous commenters, I am struggling to figure out what changed.  I had no problems for several years until recently, as my thermostat never had a C-wire previously.

[MichChiro]

Update on my case.  The C-wire adapter has helped, but I have had to recharge the unit once this week.  I did order a 90-degree micro USB wire with a 10-foot USB extesion cable.  I am thinking, if this issue keeps happening, that I'll see if I can just plug the micro USB in, run the cable down through the wall where the current thermostat wiring is, and plug the USB into an outlet in the basement.  Not sure the micro USB connection will fit with how the Nest is on the wall plate, but I figure it's worth a try to keep constant power.

[MichChiro]

Finally solved my problem!  I ended up not bothering to try the direct USB route (not sure the wall plate allowed space for the 90-degree micro USB plug anyway).  Furthermore, I am fairly confident that the Nest had an internal problem and that it was never again going to hook up to my wifi router, which was admittedly a secondary issue.  The replacement battery ultimately failed just like my original to the point it would no longer hold any charge.  I ordered an Amazon wifi thermostat, which will be nearly free after my electric company sends me my $50 rebate.  It isn't as pretty as the Nest, but my house is now staying warm and toasty on these cold Winter nights!  The app walked me right through every step, including changing the wiring configuration.  I wish I could have easily solved my issue with the Nest, but I just want the system to work and can't afford any more hours of frustration than I've already experienced.  Goodbye, Nest--hello Amazon Smart Thermostat!

[ErnieC6720]

Has anyone gotten any response or fix from Nest/Google

[BanjoBill]

I called customer support and did a reset.  Problem was still happening.  They recommend returning the product and getting a new one. I did not return the product since I determined I had a seating issue with the display to the mounting plate... When the display was touched or moved it resulted in disconnection which prompted a restart.  I remounted the mounting plate and, knock on wood, the problem has not reappeared.

[WPearce]

I had the same issue. 3 furnaces 3 nest (gen 3) thermostats. When one started to show low battery I checked all these threads and tried everything. Turns out my AC was getting low on coolant and that was causing some sort of power issue to the Nest. Had the coolant toped off and everything was fine. (Hope this helps some)

[Cbeau7]

I’m trying the warranty route. I provided some basic info on their claims page and apparently they’re going to contact me. Not holding my breath but I’d like to get partially reimbursed somehow. A learning thermostat, 3 sensors and a C wire adapter kit is $300+ which is far too much to pay for something that continues to fail without explanation. If they send me a new one at least I might be able to sell it, but I’m sure I’ll still take a loss.

[aliseb]

I called Nest Customer Service, nothing they could/would do. I asked what to do with this expensive, non supported piece of hardware, not their problem after 2 year warranty ends. I did some more digging, charged the thermostat, popped it back on the wall and reset the system. I think the update in November stopped keeping the charge without the 5th wire. So far so good with the furnace, customer service was very polite, don’t expect any help though. Reset to original settings and see what happens 

[aliseb]

Just started happening at our house too. Any resolution on your end?

[Scorpio1st]

Unfortunately no, I had to pull the Nest out and use my old thermostat. 

[Troiano27]

Wanted to add my voice. Just started happening to me yesterday (1/12/22). I’ve had my nest (I think gen 3) for number of years. Has worked without issue. I tried charging last night. Left charged for 3 hours. Put back on base, booted up. Then shut down after about a min. If I flip the breaker for my heat/cooling unit. The nest will reboot, then shut down after about a min. I have zero reason to think this is something other than the nest. 

[Troiano27]

Update on my issue. Turned out to be an issue with the heating/cooling unit. Had a clogged drain and the unit shut off so that it wouldn’t flood my attic. Had a tech come fix the issue and all is fine now. 

[TheTomasN]

I spent over an hour on the phone and let me cut it short. They kind of confirmed that with the latest update the display is using more power then before so I need to install a common C wire and they will not pay for it. 

[pdespres]

Same behavior here with a E model... hooked up a Nest Power Connector but battery drains to the point of deactivating wifi...

[ampfever]

Need a C wire that goes to C terminal on Board in furnace.. Battery  will never charge without it. It will just drain over time.

[Cgaidica]

Having same issues as other posters here as of this morning. Thermostat I have installed is at most 2 years old and does not have a C wire. Trying to charge the thermostat via usb now and hoping it works given that I live in Michigan and I can’t have a non-functioning furnace over night in January!

[Natageowild]

In Michigan too and having this same problem. Of course when it’s 12 degrees in the middle of the night on a weekend this thing goes out. 

[ftheaxe]

i am having same issues with low battery and disconnecting from wifi with my gen3. i do not have a common wire connection but thermostat has been working for over a year or so since installed without needing a charge. recently i had to charge it with usb but a 2 hour charge held for a couple of months. now it doesn't hold for even 1 night. i know my HVAC unit works fine and my wifi is also not the issue. 

[Jumanji2023]

Exact same thing is happening to me - not able to connect to wi-fi 2 errors m5 and something else - won’t hold a charge, won’t connect to wi-fi and stopped working, trouble shooter through each error message…No luck. Not going to buy A new one. Hope google nest will exchange. Wish you all luck! Watch they will launch a nest 4 soon because this one is messed up. 

[Pundamilia]

I am extremely disappointed at the lack of Customer Service on the part of Nest/Google. Recommending buying a new Nest thermostat to solve the problem here is not a very customer-oriented solution the issue. Like others, I have been through the same cycle of recharging the battery to only last for a few days. I will be replacing it with another thermostat, but not with a Nest! The same goes for all the other Nest components in my house. I will also be discouraging anyone else from buying these unsupported products.

[Pundamilia]

BTW. I would like to recommend what Nest/Google can do with their "Welcome badge" and "1st Reply" badges, but I don't want to use that kind of language in this forum. Better that Nest/Google put the resources into better Customer Service and Product Support rather than gratuitous, insulting e-mail msgs.

[Natageowild]

Just spent my whole morning with support. Resulted in them ending the chat as I complained and suggesting I buy a new one as it was 6 months out of warranty. They had me rewiring, turning breakers off etc. A $300 thermostat should last more than 2.5hrs it makes the investment not worthwhile for the energy savings. 

[Scorpio1st]

I was able to solve this by installing a C wire 24 V power adapter from Amazon for $20. 
24Volt Power Adapter/Transformer,C-Wire Adapter Thermostat，Compatible with Honeywell ,Ecobee,Nest and Sensi Smart WiFi Thermostat Pro(25Foot /7.6M Cable) https://www.amazon.com/dp/B07L4DN5R2/ref=cm_sw_r_cp_api_glt_i_A3YKYWKPGPRJNHB3TPHS

[Pundamilia]

Thanks for your response Scorpio1st. Unfortunately, the external power adapter/transformer does not pass the WAF (Wife Acceptance Factor) test. It looks like there is an EcoBee or Honeywell thermostat in our future.

[JImmerKv]

I can confirm that the external power supply does not fix this issue.   My original installation required a separate 24v power supply since the Nest thermostat wasn't getting enough voltage from the boiler itself.  The Nest worked fine for several years with this configuration, but stopped working this week.  Checked the transformer, and its still providing >24v at the thermostat.   I was going to contact support, but after reading this thread I guess I won't bother wasting my time. 😞

Update:  Despite my prior comments I did try support.   After working with the live agent, I was instructed that my unit was out of warranty and they recommended purchase a new unit.  No discount was offered.  that's insulting for an expensive purchase that's only a few years old.    I will stay away from Nest going forward.   I also sent a comment to the Wirecutter reporting all of the problems that Nest users are having.

[WillBrad]

I have a 3rd generation Nest Learning Thermostat.  I got a "Nest App Low Battery" message and the Nest disconnected from my Wifi network.  I just spoke to a technical rep with Google who asked me to check the power to the unit.  You can find that by going to Setting on the Nest and turning it to technical info.  Press on power and it should not be below 3.6 - 3.7 V.  If it is you can pull off the Nest from the wall and recharge it with an Android USB charger.  I'm using  on for a Bluetooth speaker.  I was told to charge for an hour but warned that you can only do this manual recharging once or twice.  The battery in this model is self-charging and is not meant to be replaced, according to the Google rep.  If the manual recharging doesn't work I may need a new Nest.  The Google rep said my Nest's batter could have been depleted due to a power failure, which I don't think is my problem. 

[Pundamilia]

Thanks, WillBrad. After several days of pulling off the front of the Nest and re-charging it for a few hours and having if work fine until the battery got below 3.7, I called in a furnace technician who installed the 'C' wire and now the battery stays at 3.9xx without recharging. I was lucky in that there was already a fifth wire running between the house and the thermostat so that it was easy for him to install the 'C' wire without re-routing wires through the house.

[ampfever]

I have all this but yet I get a error message..then it goes back to normal. I think Nest has a STD.

[JSC]

what is your warning message as I get one also?

[jeepwran]

At least you got a message! Ours installed 2 and a half years ago just cut out with zero warning @4:30 am on a March 12th morning with unseasonable sub-zero temps.

[jeepwran]

Update, doing a factory reset did resolve the problem. Battery voltage reported under Technical Info had been hanging around 3.65. After reset 3.87.