First Alert is a name you see in nearly every building code for a reason. Their SMI110 smoke alarm centers on a single, practical promise: a full decade of protection without a battery change. The built-in lithium power cell is sealed inside, designed to last the entire lifespan of the unit. You install it, test it monthly, and forget about the low-battery chirp for ten years.

This model uses Precision Detection technology, which is First Alert’s way of saying it’s smart about smoke. It’s engineered to distinguish between fast-flaming fires and common cooking fumes. In practice, that means significantly fewer false alarms from your toaster or a smoky pan, while maintaining a rapid response to actual emergencies. The test/silence button is a single, large pad—easy to find in a panic or to hush a nuisance alarm.

The unit is a simple, low-profile white disc that blends into most ceilings. Installation is straightforward, but note that its 10-year lifespan is non-negotiable. When the battery expires or the end-of-life chirp begins, you replace the entire alarm. This is a trade-off for absolute, maintenance-free reliability, and for most homes, it’s a worthwhile one.