All four Gen 3 Learning Thermostats have low battery

[Meiral]

I have four Generation 3 learning thermostats in my vacation home.  They have all started going offline and when I got here this weekend I saw that three of the four had low batteries. When I set them to warm the house, they say they will do so (e.g. “1 hour 5 minutes to get to 67 degrees” ) but then it’s like they forget what they are supposed to do once I walk away.  I have to go by each one every 20 minutes or so to remind it to keep on heating.   I’ve now charged each one using the USB charger for at least an hour.  One (which I charged for 6 hours) seems to be well charged (battery 3.732V Voc 35.88 V, Vin 28.5 V, Iin 20). But a second one (which I charged for 1 hour) is at battery 3.654, Voc 36.57 V, Vin 8.73 V (??!!), and Iin 20 mA.  

I’m not sure what’s going on and what to do next.  Do you have advice?

[zoeuvre]

Hi Meiral,

Yikes! For how long does that thermostat with 3.654 V last after you charged it? Also, check on the following: 

1. Ensure that your thermostats are within range of your Wi-Fi network and that the network is stable. You can try reconnecting the thermostats to your Wi-Fi network or resetting the Wi-Fi settings on the thermostats to establish a reliable connection.
2. It's unusual for the Nest Thermostats to require frequent recharging if they are hardwired. The battery on the Nest Thermostat is primarily used as a backup power source in case of a power outage. If the batteries are draining quickly, it could indicate a problem with the power supply or the thermostat itself.
3. Make sure your thermostats are running the latest firmware version. Outdated firmware can sometimes cause issues with functionality and connectivity. On your thermostat, go to its Settings > Software.

Let us know how it goes.

Best,

Zoe