I am convinced that the makers of battery-operated CO and smoke detectors must secretly want all of their customers to die of asphyxiation or burn to death.

1.) CO and smoke detectors are programmed with special factory-set timers to hit their low-battery warning state between the hours of 1am and 5am on a work night. Have you ever had one of these devices start its warning chirps at, say, 2pm on a Saturday? Me either.

2.) The battery cases on CO and smoke detectors are not made to be easily opened by bleary-eyed, sleep-deprived people in the wee hours of the night. They require a screwdriver, a chisel, or at least a determinedly-wielded butter knife to pry open, as well as intense illumination to read the “battery compartment instructions”, which were molded in 4-pt barely-raised type that blends perfectly with the rest of the case and is nearly illegible in direct sunlight, let alone the crappy 60-watt bulb in the hallway light fixture you’re standing under, squinting and cursing.

3.) By the time you’ve finally ripped off the battery cover and flung the handful of AAs to the floor to get the incessant, hellish chirping to stop, you’ve broken off some fragile but vital plastic tab that secures the batteries in place and without which the unit will simply not operate. You decide it’s probably time to replace the damn thing with a new one anyway, maybe a hard-wired unit that won’t awaken you at 3am the morning before an important work meeting, so you set it aside and decide to deal with it later. Much later. Months in the future, when your house bursts into flames (or your furnace starts pumping carbon monoxide through the vents), the plans of the evil smoke/CO detector companies come to fruition.