Alarms with traditional (alkaline) batteries are fine. But those batteries must be changed at least once a year—and you may experience a “chirping” sound when the batteries are dying, which will require your immediate attention for safety.
Instead, we recommend you get alarms that have long-life lithium ion batteries. Many alarms now come with these batteries sealed inside them; the packaging may read “Always On” or “Worry Free” or “Hassle Free.” This type of battery is designed to last 10 years, which is the average lifespan of a smoke alarm. (You can also get 9V lithium ion batteries to upgrade your existing alarms.) With lithium ion batteries, you won’t have to change the battery every year, and you won’t hear “dying battery chirps” as often. But you WILL still have to push the test buttons on your alarms every month!
NOTE: If your alarm came with a lithium ion battery sealed inside and the alarm starts to chirp, replace the ENTIRE alarm right away!
