What Battery For

Batteries for home devices

The battery each home device takes: smoke and CO alarms, thermostats, remotes, trackers, locks and cameras.

Smoke detector batteryThe battery in Kidde, First Alert, Google Nest Protect and X-Sense smoke alarms, and what the chirp means. AirTag batteryThe coin battery an AirTag takes, how to open it, and which bitter-coated batteries may not work. CO detector batteryThe battery in Kidde, First Alert and X-Sense carbon monoxide alarms, and what their chirps mean. Thermostat batteryThe battery in Google Nest, Honeywell Home, Sensi and ecobee thermostats and their room sensors. TV remote batteryThe battery in Roku, Fire TV, Google TV, LG, Samsung SolarCell and Apple TV remotes. Game controller batteryThe battery in Xbox, PlayStation 5 and Nintendo Switch controllers, and which ones you charge. Doorbell camera batteryThe battery in Blink, Ring, Google Nest and Arlo video doorbells, and which Ring pack fits. Smart lock batteryThe battery in Schlage, Kwikset, Yale, August, Level and Google Nest × Yale smart locks. Tile batteryWhich Tile trackers have a battery you can change, the coin cell each takes, and how to fit it. Scale batteryThe battery in Etekcity, Taylor, Ozeri, Withings and EatSmart bathroom and kitchen scales. Wireless mouse and keyboard batteryThe battery in Logitech, Microsoft and Apple wireless mice and keyboards, and which ones you charge. TI-84 calculator batteryThe batteries in the TI-84 Plus, Silver Edition and CE, and other TI graphing calculators, from TI. Security sensor batteryThe battery in SimpliSafe, Ring Alarm and ADT Command door, window and motion sensors. Grill igniter batteryThe battery in Weber gas grill igniters by model, where it sits, and the Traeger Flatrock’s 9V.

The battery at a glance

Batteries in home devices, from each maker
DeviceBattery
Smoke alarm (Kidde 20SDR, First Alert SMI100)2 AA (20SDR); one 9V (SMI100)
Kidde COB carbon monoxide alarm2 AA alkaline, not lithium
Google Nest Thermostat2 AAA alkaline
Roku remoteAA or AAA, as marked inside
Xbox Wireless ControllerAA (LR6), or an Xbox rechargeable battery
Blink Video Doorbell2 AA 1.5-volt lithium
Schlage Encode or Connect lock4 AA alkaline
Apple AirTagOne CR2032 lithium 3V coin
Tile ProCR2032; a 2018 or 2020 Mate takes a CR1632
TI-84 Plus4 AAA and an SR44SW backup cell
SimpliSafe Entry SensorOne CR2032
Weber Q grill igniterOne AAA

Each page lists more models.

Where we get our information from

The batteries come from each device maker’s own manuals, help pages and product pages. Checked against published data from Kidde, Google, Xbox, Blink and Tile (plus 7 more).

See all 19 sources
  • Apple Support, How to replace the battery in your AirTag (published October 14, 2026)
  • Kidde, Smoke Alarm, AA Battery Powered 20SDR (product page)
  • Kidde Support, What Causes Consistent Chirping?
  • First Alert, SMI100 Smoke Alarm user's manual (M08-179721, PDF)
  • Kidde, Battery Powered Carbon Monoxide Alarms user guide (G-000069-00: COB, COBD, COBDL, COB10, COBD10, COBDL10), PDF
  • Google Nest Help, Batteries for Nest products
  • Google Nest Help, How to change Nest Thermostat batteries
  • Roku Support, General battery handling and disposal
  • Xbox Support: Using batteries in your Xbox Wireless Controller; Charge your Xbox Elite Wireless Controller Series 2; What to do if your Xbox controller didn't include batteries
  • Xbox, Xbox Wireless Controller (product page)
  • Blink Support, Blink Video Doorbell Technical Specifications
  • Blink Support, How to Power your Blink Camera
  • Schlage: Encode and Connect smart deadbolt tip sheets (PDF), and the Encode BE489WB product page
  • Tile (Life360 Support), Replace a Tile Battery
  • Tile (Life360 Support), Tile Models
  • Texas Instruments Knowledge Base, Solution 11876: Batteries Used In Texas Instruments Graphing Calculators
  • Texas Instruments Knowledge Base, Solution 11885: Guidelines and Precautions for Replacing Batteries in TI Graphing Calculators
  • SimpliSafe Support: replacing the Entry Sensor, Motion Sensor Gen 2 and Motion Sensor Gen 1 batteries
  • Weber Consumer Care, What type of battery do I need for my igniter?

Elsewhere on What Battery For

HomeSizesCar keysHealthOutdoorsBackup powerGuides

Battery sizes come from battery makers' datasheets and device makers' own manuals and help pages. Check your device's manual or the old battery before you buy. If anyone may have swallowed a battery, call the National Battery Ingestion Hotline at 1-800-498-8666 or your poison center at 1-800-222-1222 straight away.