What powers a smoke alarm?

Smoke alarms are powered by battery or they are hardwired into the home’s electrical system. If the smoke alarm is powered by battery, it runs on either a disposable 9-volt battery or a non-replaceable 10-year lithium (“long-life”) battery. A backup battery is usually present on hardwired alarms and may need to be replaced.

These batteries must be tested on a regular basis and, in most cases, should be replaced at least once each year (except for lithium batteries).

Show All Answers

1. Why should I have a working smoke alarm?
2. What powers a smoke alarm?
3. What types of smoke alarms are available?
4. Where should I install smoke alarms?
5. Are smoke alarms expensive?
6. Will the Fire Department assist in installing smoke alarms?
7. What kind of maintenance do smoke alarms require?
8. My smoke alarm goes off because of steam; what should I do?