Comment 573 for bug 59695

what a mess. re: "you simply can't run long enough on batteries for this to happen", well, it's easy to. Unplug your computer, use it for three hours wherever, then suspend/shut it down/ignore it and plug it back in for a while to recharge, then repeat. Do this every day. It's easy to have a habit of almost always running on battery.

P.S. personally "plugged in" is not a good match for "not in danger" -- even when plugged in, my computer can often easily slip out of my lap, but sometimes I run not-plugged-in on the top of a stable desk. So I have a bit of an issue with using "on battery" to mean "likely to be dropped while being used" (if it's not being actively used, then I'm guessing there probably will not be much disk activity so the disk/head might as well be parked anyway?)