Beeping or chirping smoke detectors are beyond annoying. Usually, a chirp every 30 to 60 seconds just indicates a low battery ...

Nest's smoke detectors change colors when the batteries need to be changed, and give you nightly audio updates about the state of your home. "It lets you know you're being watched to keep you safe ...

which is much better than the mystery squeal that comes from most smoke detectors when the battery is dead. This is the second product from Fadell and Nest. The first product was the Nest ...