I have had my Nest now from about 1.5 yrs and have not had any problems until this week. All of a sudden my Nest battery would not keep a charge. My system did not have the C wire connected so it was siphoning power from the cold/heat wires. If I plugged it into the USB it would charge up fine but I could watch it slowly drain to below 3.6 volts and watch all the features disable one by one. This morning I connected the 5th unused wire to the C connection on the HVAC unit and the Nest. Now the Nest seems to be keeping the battery charged to 3.91-3 volts.
I am also seeing periods of time where the Nest is not connected to the network on the iPhone app. If I go to the Nest it shows connected. It's not a problem with my internet connection either as I am able to access this site from the same wifi access point when the App reports no connection to the Nest. That is a new problem as well. The battery shows 3.91V on the Nest so it's not an issue with the Nest cutting off wifi to save power. I have a Cisco (Linksys) wifi router.
So what changed? I see there was a software update around June 21st, 3.5.1 which I am on. Did something change that now requires a C connection to keep the battery charged properly? I even reseated all the wires on the nest just to make sure they were getting good connections before connecting the C wire. Even after the reseat it was draining the battery. If it hadn't been working flawlessly for 1.5 yrs I might understand the need for the common power, but the sudden change has me wondering about the software update because that is the only thing that has changed with the setup. I also see that "Wi-fi connectivity bug fixes" is on the software update list for 3.5.1, so I am also wondering if that has introduced my random access issue as well.
I want to let you know we’re aware of issues with Wi-Fi connectivity that started with the 3.5.1 software update and we’re aggressively investigating it to find a fix. Check out the statement from our Community Manager, Brian at the link below.
We’ll be sure to let the community know when we’ve got updates to share.
Tyler if you’re having issues with connectivity since the update, I’d recommend you restart your Nest if you haven’t already.
Please give support a call if you’re still running into trouble so we can give your issue the individual attention it deserves. You can call us at 855-4MY-NEST (855-469-6378). Our support team is available 7 days a week from 5 am - 9 pm pacific.