How long will my neighbor's smoke alarm chirp?

Question

I know that smoke alarms will chirp once every minute when the batteries need to be changed. The problem: it is my neighbor (who appears to be away for the summer) who has the dying batteries. For the past three days, his alarm has been beeping once every minute. These hot summer nights, his window is open and so is ours. How long will the !@#$% beep before it runs out of enough juice to beep like this?

Answer 1

If the windows are open, then someone is taking care of the place, soooo go knock on the door and hand them a new battery if you have extras. Some people are oblivious to what the noise may be and they will probably appreciate your help.

Answer 2

If the smoke alarm is a battery powered one, it will beep until all the energy in the battery is used up. That could be for a full mounth. If the alarms are hard wired(110 AC) they will beep until someone changes the battery, or the power is shut off(beeping will last about 12 hrs.)

Answer 3

mine beeped for like a week.