How to replace Nest Protect's batteries

When it’s time to replace your Google Nest Protect’s batteries, you can follow the steps in this article to learn how.

Note: If you’re adding your Protect to the app and you get a notification that the batteries are low, the voltage may have temporarily dropped. Go to Troubleshoot when Nest Protect batteries seem low during setup.

Protect requires lithium batteries

Both battery and wired Protect require Energizer Ultimate Lithium AA (L91) batteries.

Protect (Battery) requires 6 AA and Protect (Wired) requires 3 AA as backup batteries. In case of a power outage, Protect (Wired) will use its backup batteries.

Don’t use rechargeable or alkaline batteries. If you do, they will quickly drain and will need to be replaced soon after installing them.

Using other types of batteries than the ones recommended by Nest will be detrimental to the smoke and CO alarm operation.
Don’t mix and match batteries.
Don’t place new batteries in with old batteries.

How to tell when you’ll need to replace Protect’s batteries

When your batteries are getting low:

Protect will pulse yellow when you turn off the lights at night.
You’ll get a message during Nightly Promise.
The Nest app will notify you.
When the batteries are very low, your Protect will chirp until the batteries are replaced.

You can also check the battery life of your Protect at any time.

Check the battery charge level

Check Protect’s battery level

Open the Nest app.
On the home screen, select the Protect that you want to check.
Here you’ll see the battery status and the last time the battery level was checked by Protect’s Self Test.

Nightly Promise

Protect’s Nightly Promise lets you know everything is working, and that the batteries are at a safe level. If the batteries are getting low, you’ll see a yellow light and you’ll get a message telling you to replace the batteries soon.

You can also check the battery level at any time with the Nest app.

Wired and battery powered Protects both use batteries (wired has batteries for backup power) but each have their own unique behavior depending on their battery charge level.

Battery powered Protect

When Protect has less than about a year of battery life remaining, it will give you a warning that the batteries are getting low. Protect will pulse yellow when you turn off the lights at night and after you press the center button it will say “The battery is low. Replace the battery soon.” You will also receive a message in the app.

Protect will pulse yellow again and send you a second warning in the app when there’s only a few months of battery life left. When Protect has only a few weeks of battery life left, it will chirp until the batteries are replaced.

What you'll see and hear from Nest Protect

Wired Protect

When there’s a power outage, wired Protects use their backup batteries to keep all features up and running. If the backup battery charge is low, the Protect light ring will glow yellow. When you press the center button, Protect will say: “Nest Protect battery is low. Replace it soon.”

We designed wired Protect for multiple years of battery life. If you have a consistent source of power, the backup batteries should last the life of the Protect.

What you'll see and hear from Nest Protect

Replacing your Nest Protect's batteries

Each kind of Nest Protect has different instructions for replacing the batteries. To check which kind of Nest Protect you have, see the article below.

How to tell which Nest Protect you have

Select the kind of Nest Protect you have to see how to replace your Nest Protect's batteries:

2nd gen battery powered Nest Protect

1. Remove your Nest Protect from its backplate. Turn it counter- clockwise until it comes loose.
2. Push the battery door button in the direction of the arrow. The door will spring open.
3. Replace all of the batteries with new Energizer Ultimate Lithium AA batteries (L91). Be sure to match the positive "+" and negative "-" ends of the batteries with the markings in the battery compartment.
4. Close the battery door. It will click into place. For your safety, the battery door will not close until all 6 batteries are inserted.
5. Using the notches on the bottom of your Nest Protect as a guide, place your Nest Protect against its backplate, and turn it clockwise until you feel the backplate grip.
6. Press the Nest button twice to test your Nest Protect. This will help make sure you've replaced the batteries correctly. Learn about Safety checkup

2nd gen wired Nest Protect

1. Turn the power to your Nest Protect off at the breaker box.
2. Remove your Nest Protect from its backplate. Turn it counter- clockwise until it comes loose.
3. Detach the power connector.
4. Push the battery door button in the direction of the arrow. The door will spring open.
5. Replace all of the batteries with new Energizer Ultimate Lithium AA batteries (L91). Be sure to match the positive "+" and negative "-" ends of the batteries with the markings in the battery compartment
6. Close the battery door. It will click into place. For your safety, the battery door will not close until all 3 batteries are inserted.
7. Reattach the power connector.
8. Using the notches on the bottom of your Nest Protect as a guide, place your Nest Protect against its backplate, and turn it clockwise until you feel the backplate grip.
9. Turn the power back on at the breaker box.
10. Press the Nest button twice to test your Nest Protect. This will help make sure you've replaced the batteries correctly. Learn about Safety checkup

1st gen battery powered Nest Protect

1. Remove your Nest Protect from its backplate. Turn it counter- clockwise until it comes loose.
2. Using a Philips screwdriver, unscrew the two screws from the battery door.
3. Replace all of the batteries with new Energizer Ultimate Lithium AA batteries (L91). Be sure to match the positive "+" and negative "-" ends of the batteries with the markings in the battery compartment. Push down the small latch at the bottom of the battery compartment so that you can insert the last battery and properly close the battery door.
4. Reattach the battery door. Slide it into the tabs located on the opposite side of the batteries and replace the screws. For your safety, the battery door will not close until all 6 batteries are inserted.
5. Place your Nest Protect onto its backplate and turn it clockwise until you feel the backplate grip.
6. Press the Nest button twice to test your Nest Protect. This will help make sure you've replaced the batteries correctly. Learn about Safety checkup

1st gen wired Nest Protect

1. Turn the power to your Nest Protect off at the breaker box.
2. Remove your Nest Protect from its backplate. Turn it counter- clockwise until it comes loose.
3. Detach the power connector.
4. Using a Philips screwdriver, unscrew the two screws from the battery door.
5. Replace all of the batteries with new Energizer Ultimate Lithium AA batteries (L91). Be sure to match the positive "+" and negative "-" ends of the batteries with the markings in the battery compartment. Push down the small latch at the bottom of the battery compartment so that you can insert the last battery and properly close the battery door.
6. Reattach the battery door. Slide it into the tabs located on the opposite side of the batteries and replace the screws. For your safety, the battery door will not close until all 3 batteries are inserted.
7. Reattach the power connector.
8. Place your Nest Protect onto its backplate and turn it clockwise until you feel the backplate grip.
9. Turn the power back on at the breaker box.
10. Press the Nest button twice to test your Nest Protect. This will help make sure you've replaced the batteries correctly. Learn about Safety checkup

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