After an upgrade to powersave-0.13.4, kpowersave shows a missing battery, and interestingly it show 'Battery 1' as a label.
Could it be the readings are being made from /proc/acpi/battery/BAT1 and not from /proc/acpi/battery/BAT0 as it should?
Don't restrict bugs without any reason. Just leave the checkboxes alone.
This version is not in portage any more, reopen if you can reproduce it w/ 0.14.0.
powersave-0.14 fixed the problem