Szerintem itt a megoldásod:
I use Debian with the laptop-mode-tools package, which seems to be the trigger for the problem (the actual cause being some ACPI bug in the kernel, apparently). Until that gets fixed, this was my workaround (based on https://bbs.archlinux.org/viewtopic.php?id=133108). The solution is Debian-specific. It includes a solution for another problem (error messages about the intel gigabit module e1000e slowing down shutdown)
Create a file called shutdownfixes.sh in /etc/init.d, as root:
### BEGIN INIT INFO
# Provides: MIHAI
# X-Stop-After: $network
# Default-Stop: 0
# Short-Description: Things added by Mihai for shutdown.
# Description: Things added by Mihai for shutdown.
### END INIT INFO
echo -n "Preparing PCI busses for shutdown..."
for i in /sys/bus/pci/devices/*/power/control; do
echo on > $i
echo -n "Removing e1000e module..."
lsmod | grep -q e1000e && rmmod e1000e
And make it executable:
chmod ugo+x /etc/init.d/shutdownfixes.sh
Then install it:
update-rc.d shutdownfixes.sh start 8 0 0 .
And the next shutdown on battery should be clean. Hope this helps someone.