Hardwired smoke detector vs. battery-operated One of the biggest decisions when choosing a smoke detector is whether to opt for a hardwired or battery-operated model. Both have their advantages.

That is what’s known as the “end-of-life” chirp: When your smoke detector lets you know that it can no longer do its job, and now must die (i.e. you have to replace it with a new one).

North Shore Fire Lt. Dan Tyk said smoke detector maintenance needs to become a priority. "We can preach a message all the time about changing your clock and changing your battery," he said.

This 4-in-1 smoke detector comes with a smart back-up battery, but that’s as high as it raises the bar. By Michael Brown Oct 26, 2016 6:00 am PDT At a Glance Expert's Rating ...