The most commonly used smoke alarm battery has been the 9-volt alkaline variety, but with the rise of lithium use in batteries, that has changed. 9-volts were used because of their easy installation and relatively long life. Lithium manganese batteries, however, are unmatched in terms of their lifespan relative to their size. More and more, a smoke alarm battery offers a 10-year life, meaning you won't have to change it for a decade.
Long-Life Smoke Alarm Batteries
In actuality, 9-volt batteries are still used, although the chemistry involved in making the battery is different. As opposed to somewhat outdated 9-volt alkaline batteries, lithium manganese dioxide is the primary component. This more recent battery design is what gives new smoke alarm batteries their long life. 9-volt lithium manganese dioxide batteries feature the same specifications as traditional alkaline 9-volt batteries. Thus, their terminal position is identical, making them perfectly suitable for any DC-powered smoke alarm.
Despite the fact that new smoke alarm batteries are designed to last for a decade, it is always a good idea to be sure the battery is still operational. Smoke alarms are useless if without power. Periodic testing of the smoke alarm should become a ritual in your household so you can be sure the lifesaving detectors are always functional.