How frequently should smoke alarm batteries be replaced?

Smoke alarm batteries should be replaced twice a year to ensure that the devices remain functional and can effectively detect smoke and provide adequate warning in the event of a fire. This semiannual replacement aligns with safety recommendations from organizations like the National Fire Protection Association (NFPA) and the United States Fire Administration (USFA).

The rationale behind this recommendation is based on the fact that batteries can lose their charge over time. By changing them twice a year, ideally coinciding with seasonal time changes, you are creating a reliable schedule that helps ensure the smoke alarms work when needed most.

Additionally, it's important to regularly test smoke alarms monthly to verify that they are functioning correctly; however, replacing the batteries on a twice-a-year schedule provides a good compromise between regular maintenance and practical usability for most households.