How does the Roost smart battery work with interconnected smoke alarms?

If your smoke alarms are interconnected, when one of your alarms sound, all of your alarms with Roost Smart Batteries installed will notify you. While installing only one Roost Smart Battery will enable smartphone notifications for all alarms, we recommend you install a Roost Smart Battery in every alarm so that you'll get an early notice of a low battery in any one alarm. No more 3 AM chirps!