Door / Window Sensor 8 utilizes a 1/2 AA CR14250 3.0V lithium battery. Because this is a specialized size, it is rarely stocked in standard brick-and-mortar stores in the United States and is best sourced online.


Important Battery Specifications: When purchasing a replacement, ensure the battery meets these exact specifications to avoid damaging your sensor:

  • Size: 1/2 AA (Half-AA)

  • Type: CR14250

  • Voltage: 3.0V

  • Chemistry: Lithium Manganese Dioxide (Li-MnO2)

(Note: Do not confuse this with ER14250 batteries, which are 3.6V Lithium Thionyl Chloride and may damage the device, or rechargeable 3.7V batteries).


Where to buy in the US: The most reliable way to purchase these batteries is through major online retailers. Searching for "CR14250 3V battery" will yield the correct results. Below are some links we've found:


Amazon: Usually offers multipacks from battery brands like EEMB or PKCELL.

Specialty Battery Retailers: Websites like BatteryJunction or DigiKey carry high-quality cells.