Around 2 am on Saturday morning, my wife and I were awakened by a high-pitched chirping noise. It turns out that the batteries in our carbon monoxide detector were running low, and it wanted them replaced immediately. So, I thought I would compare this behavior to how some other products in my house alert you about low batteries:

– Alarm clock: Says “low battery”, or the screen gets dimmer until you figure out the message
– BlackBerry: Shows a low battery icon on the screen for a while, and eventually beeps when it gets critically low
– Nokia phone: Beeps annoyingly until you plug it in

There’s certainly a lot of variance here. The best practice seems to be a two-phase notification. First, provide a polite reminder that the battery is running low, such as showing a battery icon on the screen or sounding a periodic, moderate beep. Then, if the user still hasn’t taken care of the issue, you can break out the loud and annoying version. When you do this the wrong way, and come in with guns blazing as soon as the battery runs low, you’ll cost users a little bit of their sanity — and in my case, a good night’s sleep.