If you design a product that might wake me up in the middle of the night, you should meet the following bar: I, or someone I love, must be in danger. Not a hypothetical “If the power goes out and if something in the house is still managing to produce CO without power” type of danger, but something more actual and imminent.
Smoke and CO detectors seem to have been designed with a severe disregard for how the customer will react to the various interaction points other than a true emergency. I can remember several times in my adult life when a chirping detector has induced me to get out a ladder in the middle of the night and climb up to check on various possible sources of the chirp, all in a semi-alert state.
Last night, the culprit was a CO detector that happened to be plugged in to the wall in our master bedroom, perhaps about 3 meters from where I sleep. The acoustics of the alert sound on this device seem to have been designed to make it echo and reverberate around the house, which is great for an a alarm, but again is horrible for a low battery warning. In my efforts to find the noise that only repeated every minute or two I got out two different ladders, stood on the ladder near the upstairs smoke alarm, then the downstairs one, then climbed into the attic to check that one, then stood in the room listening for the chirp again, then up to the attic to see if maybe there was another alarm up there that I didn’t know about. Thankfully my wife happened to look down at the right moment and correlate a chirp with this CO detector plugged in to the wall.
I know that I should have probably replaced the battery at some point, but honestly I had totally forgotten about this particular detector. It’s one of 3 CO detectors in our house, and I’m pretty sure that it’s been 3 or 4 years since the battery was changed because it runs off house power and the battery is just for power failures. The end result of this particular warning was that the device was unplugged and batteries removed so that we could get back to sleep.
This morning as I tried to get back to sleep I was wondering how many middle-of-the-night ladder injuries are attributable to low-battery chirps. I’m guessing that the low battery behavior is probably design-by-regulation and that manufacturers like First Alert don’t have a lot of latitude to make this better, but I see that Nest Protect is trying to solve the UX gap, although at quite a premium on price.