I haven't heard that, but I assumed one of three things went when it happened: 1. the Nest was fully charged when I bought it and then was unable to charge itse

I haven't heard that, but I assumed one of three things went when it happened: 1. the Nest was fully charged when I bought it and then was unable to charge itself enough from the fan running and went dead, 2. something happened to the wiring on my heating system to cause it to not charge, or 3. something happened to the Nest itself. The first assumption was addressed by several heat and air contractors on Youtube, so I hooked up the common 24v wire to ensure it would charge and it immediately started working again. This required me to hook up the wire on the heating unit itself, and the Nest. Given I've worked with electronics and have built parts of houses, done wiring, plumbing, etc., it was a 5 minute job for me. The Nest was built to provide a feature by which it could charge itself off the latent, low power current that runs through the fan wire while it is running. This is one of those cases where more features equals more things to break when you push.