This solution seems to work great (part of my .xinitrc):
while true; do # Set root title sh $HOMEDIR/.xsetroot # Check battery level BATT=$( acpi -b | sed 's/.*[charging|unknown], \([0-9]*\)%.*/\1/gi' ) if [ $BATT -le 5 ]; then # Beep echo -e "\007" >/dev/tty10 && sleep 0.2 echo -e "\007" >/dev/tty10 && sleep 0.2 echo -e "\007" >/dev/tty10 && sleep 0.2 # Blink echo 'on' > /proc/acpi/ibm/light && sleep 1 echo 'off' > /proc/acpi/ibm/light fi # Update every 30s sleep 30s done & It beeps 3 times and flashes the ThinkLight every 30s, in case the battery level is below 5%. --Danilo