Fire alarm batteries are one of the most important components in the entire fire alarm system, because if they don't work properly, things like the horn would not sound, rendering the entire system useless in its role of warning people. Such small objects with such as important responsibility should not be neglected or overlooked.
While this may seem like a small matter, you might be
surprised to learn that not many people actually remember about
their fire alarm batteries. Whenever a fire alarm battery goes
dead, the system alerts you by emitting a weak alarm, and most
folks then simply switch the alarm off, throw the dead battery
away, and then forget to replace them. This often happens at
night as well, and the annoyed building occupants just pull the
batteries out in frustration and then forget about replacing
So, it might probably be good advice on the part of fire alarm companies to suggest that the alarms be tested once a month. Since it takes only a moment, you will quickly know whether the batteries need to be changed or not. There should be a test mode button on all smoke detectors to test the batteries. Also, it is suggested that the batteries be changed once a year, while the fire alarms should nominally be changed every decade or so.
Are there any fire alarm batteries that could last a long time, maybe a decade without flat lining out? This is possible today, with nine-volt lithium batteries that can indeed last a decade, so you don't have to worry about changing the batteries every year. These batteries also come with safety mechanisms for family friendly home usage.
At the end of the day, you need to be certain that your fire alarm batteries are working alright so that your fire alarm system gets to do what its meant to - Protecting your home from fire.