Fire safety experts recommend you replace your smoke alarm battery two times a year.
Fire alarm battery replacement.
A good rule of thumb is to change.
Replace the backup battery in a hard wire unit yearly whether it beeps or not.
Mark the date you changed your battery on the inside of the smoke alarm.
Buy a new smoke detector.
No one wants to realize once the inspector arrives or after their business has a fire that their panel is malfunctioning due to low or no battery life.
If you have an ac hardwired interconnected alarm you will need to remove the quick connect wire harness from the back.