Battery for Nest Thermostat E, Learning Thermostat 2nd / 3rd Generation T3007ES, T3008US - (380mAh) Replacement battery
Cameron Sino Replacement Rechargeable Battery fit for Nest Learning Thermostat 2nd Generation (380mAh) : Amazon.ca: Electronics
Nest thermostat says it has a low battery and won't connect to wifi anymore. Checked the technical info and from what I've read, all numerical values check out that it should be