The Smart Battery will work in most smoke and combined smoke/carbon monoxide alarms that presently use a common 9V battery. This includes both 9V battery-powered alarms as well as AC-powered alarms with 9V battery backup.
For a list of alarms with known issues, please see our Help Center article: Are there any alarms that do not work with the Roost Smart Battery?
Please note that we do not offer any warranty for Roost batteries used in smoke or combined smoke/CO alarms older than 10 years based on the manufacturing date on the alarm. If an alarm has no manufacturing date, we cannot warrant the use of the Roost Smart Battery in this alarm.
Please see our Help Center article: When should I replace my smoke alarm or smoke/CO alarms?
You may also want to see our Help Center article: Where else can I use the Roost Smart Battery?