Google Nest Community

This thermostat has been disconnected for about a year. just reinstalled, trying to connect to the internet, it says "low battery". Will it charge now that it's back on the wall?

We had an older Nest Learner thermostat, got a new furnace and a new thermostat, and cannot get it to work.We installed our new Nest Learning thermostat, I followed the directions for set-up and got the message on the Nest app on my phone that I was ...