The Nest Thermostat receives power from your HVAC system. It also uses 2 AAA alkaline batteries as a backup, or to supplement if your system can’t deliver enough power.
You can’t replace the batteries for the Nest Thermostat E or Nest Learning Thermostat. Instead, charge the thermostat with a USB cable.
This article only applies to the Nest Thermostat.
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How to tell which thermostat you have |
Low battery warning during setup
During initial setup, you may get a low battery message. This can happen if the batteries are loose or there’s a piece of the battery tab still stuck to the contacts.
- Pull the thermostat display off the base.
- Make sure you’ve completely removed the battery tab. Pull out the batteries from the back of the thermostat display and check that there aren’t any pieces of battery tab left.
- Put the batteries back in and make sure they are fully seated and facing the right way.
- Push the thermostat display back onto the base until it clicks into place.
- If the low battery message doesn’t go away, replace the batteries with high-quality 1.5 V AAA alkaline batteries from a known manufacturer.
Low battery warning after setup
Repeated low battery warnings
If you repeatedly get low battery messages from your thermostat, or if there’s another power-related message, you may need to check the C wire connection or install a C wire to provide consistent power to your thermostat and prevent the backup batteries from draining. Some systems, including heating-only, cooling-only, zone-controlled, and heat pump systems, require a C wire or the Nest Power Connector. Go to g.co/nest/cwire for details.
- Replace the batteries by following the directions in the section below so your thermostat can control your system (and you can stay comfortable) while you check the C wire.
- After you put in fresh batteries, go to Fix or connect a C wire for additional troubleshooting help.
How to replace the batteries
Important: Use only high-quality 1.5 V AAA alkaline batteries from a known manufacturer.
- Pull the thermostat display off the base.
- Remove the old batteries from the back of the thermostat display.
- Insert the 2 new AAA alkaline batteries.
- Push the thermostat display back onto the base until it clicks into place.