The type of battery used in smoke detectors can vary, but the most common types are 9V and AA batteries. Previously, 9V batteries were the most common, but nowadays, it is more common to see two or three AA batteries in smoke detectors. AA batteries have about three times as much energy as a 9V battery, but its important to check them consistently and replace them every six months. Some smoke detectors come with a built-in battery that lasts for 10 years, eliminating the need for battery replacements.

Its important to know what type of battery your smoke detector uses and to replace it regularly to ensure that the detector functions properly. The battery in your smoke alarm should be something that you can rely on. First Alert recommends a 10-Year Sealed Battery Smoke Alarm, which contains lithium batteries that last for the life of the alarm.

If your smoke detector starts to chirp, its a sign that the battery is dying and needs to be replaced immediately, regardless of where you are in the 6-month replacement cycle. Its recommended to replace smoke detectors every 8-10 years, even if they have replaceable batteries.