Comment 32 for bug 838543

A similar bug is affecting me, and maybe my situation can shed some light. I actually DO have two batteries in my laptop. If one of the batteries is depleted when I resume from sleep, I see this "battery is critically low" warning followed by suspend, even though the other battery has plenty of power. While the machine is running, the first battery drains without any problem, so this seems to just be a wake-from-sleep issue. Likewise, if I reboot the machine with one battery drained, it boots fine.

So my uneducated guess is that there's some battery-low event handler somewhere that gets triggered on wake and doesn't properly check the total power in all batteries. It looks like other reporters are having (an unrelated?) problems with phantom batteries, which could be leading them to the same issue I'm having with real batteries.