What powers a smoke alarm?

Test Your Alarm MonthlyThere are two types of power sources for smoke alarms:

  • Battery: Battery-powered smoke alarms run on either a disposable 9-volt battery or a non-replaceable 10-year lithium ("long-life") battery.
  • Hard-Wired: Hard-wired smoke alarms are connected to the home’s electrical system. A battery back-up is in place in case of a power failure and may need to be replaced periodically.

Test Your Alarms

Smoke alarms should be tested once a month by pressing the test button located on the device. Batteries should be replaced once a year (except for lithium batteries)....for safe practices, change your batteries every time you change your clocks!

Show All Answers

1. Why do I need a smoke alarm?
2. How do they work?
3. Where in my home should I install them?
4. What powers a smoke alarm?
5. How much do they cost?
6. Where can I purchase them?