Google Nest Protect Smoke Alarms Last 10 Years From Manufacture Date

Google Nest Protect smoke and CO alarms are designed to last 10 years from their manufacturing date, not from when they are activated. Three months before expiration, the device sends a push notification, and it will chirp continuously if not replaced after that date. The second-generation Nest Protect follows the standard 10-year lifespan for smoke and CO sensors. While Google discontinued the product in 2025, many units remain in use, and users generally report high reliability, though some have noted an 8-year lifespan in certain cases. New, sealed Nest Protect units are still available online, such as on eBay, with some working until the 2030s, but they can cost up to $200. Alternatives like the X-Sense SC07-MR offer similar smart features for $46, with optional professional monitoring.