James's Weblog

I know these things save lives and all, but I really hate the ones we have in our home.

When their batteries get sufficiently drained, they emit a short, annoying, loud chirp once a minute. It seems to me that whoever thought this up never lived in a home with a smoke detector in every room. It takes around 10-15 minutes to track down which smoke detector is complaining, because:

• We have a lot of smoke detectors.
• The chirp is too short to get a good fix on the location immediately.
• Funny acoustics can play tricks.
• I have to wait a full minute to refine each guess.

Ten to fifteen minutes isn’t a long time, but it’s longer than it ought to be. Listening to the shrill, piercing chirp doesn’t make the time spent any more enjoyable. (And why do these chirps always seem to start in the middle of the night while you’re sleeping?) The chirps seem to go on forever; just how low on power can the batteries possibly be? At my old apartment complex in Berkeley, I listened to one go on for weeks.

What I don’t understand is that the smoke detectors are wired to get power from the house. The batteries are supposed to be used only as a backup. How are they getting depleted so quickly?

Of course, a good high-tech solution would be to connect all the smoke detectors to a network and to have a central monitoring system.

Better low-tech solutions:

• Use a rechargeable battery; signal a warning only when the battery can no longer retain a sufficient charge.
• Use visual cues instead of (or in addition to) the chirps for battery warnings. For example, a smoke detector could turn off its power LED when battery power is low (and thereby save electricity too); it could release a short, brightly colored ribbon and let it hang; or it slide open a hatch that reveals some brightly-colored material underneath.
• Use less annoying chirps and chirp more frequently. It’s silly to design a smoke detector that can signal a low-battery warning for several weeks. Even two chirps in quick succession would be a huge improvement.
• Get a dog.