Did someone steal the americium?
September 25, 2011 11:40 AM Subscribe
Why did my two smoke alarms stop working altogether when the batteries ran down?
posted by le morte de bea arthur to technology (7 answers total)
I have two smoke alarms which I installed on the same day, two years ago. One is in the downstairs hallway, one is at the top of the stairs. They are both the round white 9V PP3 battery powered ionisation type. I changed both batteries a year ago when the alarms started to do the beeping thing that indicates low battery power. I test both alarms regularly, and the one downstairs does occasionally go off if I overcook the bacon. So I know they've worked fine all this time.
Last week, one of my two smoke alarms started to do the battery beep again. I put in a new alkaline battery. The alarm didn't work. I tried another battery from a different batch. Still no luck. The alarm appears to be dead.
Then, today, the second alarm started to beep. I replaced the battery. Again, the alarm didn't work. So that alarm also appears to be dead in a manner identical to the first.
So what happened? Is this just coincidence, or is there some mechanism (inbuilt expiry or something) that would cause this apparently identical failure after a nearly identical time?