NEST not holding a charge

[Lindsay_Stevens]

I’ve had my nest for appx 3 years, I’ve never had a problem with it since installation. Of course now it’s 3am in the winter in Buffalo and it’s not working. My system apparently doesn’t have a C wire but my nest has worked faithfully without one the entire time. Now all of a sudden it’s not turning on until I pull it off the wall and it says the battery is low. I don’t understand why it’s doing this all of a sudden. The wires it uses are y1, g, w1 and Rh. If anyone can help I’d really appreciate it.

[analogue_dsp]

I just started having an issue where my thermostat (which has worked well for ~4 years, if you forget about the fact it thinks it knows what I want) says it's power is low. I can press the button and it shows the temp, but turning it does nothing. Press again it shows the menu, but you can' t select anything, because turning does nothing. It says low power.  Am I right in assuming inside the nest there is a rechargeable battery that after n charges over 4 years will no longer hold a charge; and the recommended solution to that is for me to crawl through the attic and run another wire? 
If that is the case, I'm going to chunk it. This all seemed to start right after a firmware update was pushed. Maybe the "auto-sense" wiring is busted and it selected the wrong wires.? is that even a possibility?

[analogue_dsp]

Update: added a C wire, just pulled a 4 wire strand through using the old 3 wire strand, and hooked it all up. Not rocket science. However, it still sometimes is unresponsive to touch (but not network commands) and sometimes it drops off network (using google mesh router, 10ft away from nest is the master, no RF interference nearby, closest device is another 10 feet the other way). I swear it seems like something must have changed in software. 

[Lindsay_Stevens]

Yeah mine still won’t connect to the network. It works but I can’t use the app.

[Thuneyluviso]

Just wanted to chime in.  There are a couple of other things that can drain the battery when your Nest does or doesn’t have a c-wire.  I learned these the hard way after six years of owning one.  Yes it “should” be able to run on the battery, however, it uses the battery power to connect to wifi and if the wifi signal is weak, the Nest will continually try to connect to your network if it the signal keeps dropping.  Mine runs of a Gryphon repeater and when it went kaput, so did the Nest battery.  The second thing that can cause battery drain, specifically if your Nest is wired, is your HVAC system.  For example, if your furnace shuts down due to say, a clogged air filter, then the Nest will also because that’s where it is drawing its power from if it is wired with a C wire

Hope this helps.

[Polno]

Thank you, this is insightful and probably what happened to me.  I joined this community board because I was desperate to get my Nest going again in frigid temps.  You can see some of my posts from the winter.  Ultimately, I decided the battery was fried, ordered another one along with a tool kit that is necessary, but after days of cold, I just got a $30 thermostat and it works.  The Nest/new battery/toolkit is in a bag that might as well be trash, I doubt I'll ever go back.  The fact that Nest has no customer support was the final nail in the coffin for me.

[Thuneyluviso]

Glad to help.  My HVAC guy recommended an Ecobee a while back.  My Nest battery too was fried this weekend so I bought the Ecobee off Amazon.  So far, so great and there are some nice fine tuning tools the Nest doesn’t have.

[Greg_in_MI]

I saw some new replies recently so thought I would update mine. I uninstalled my Nest at the home with the furnace with no C-Wire but kept it in a box. We ended up buying a new home with a furnace with a C-wire. Even though the Nest battery wouldn't stay charged in the old home/furnace, once I installed it with a C-wire it has been running fine for 6+ months.