Adds a low battery cron job

- See https://bbs.archlinux.org/viewtopic.php?id=138755

lowbatterycron.sh

@@ -0,0 +1,11 @@
+#!/bin/bash
+
+BATTINFO=`acpi -b`
+BATTERY=/sys/class/power_supply/BAT0
+REM=`grep "POWER_SUPPLY_CHARGE_NOW" $BATTERY/uevent | awk -F= '{ print $2 }'`
+FULL=`grep "POWER_SUPPLY_CHARGE_FULL_DESIGN" $BATTERY/uevent | awk -F= '{ print $2 }'`
+PERCENT=`echo $(( $REM * 100 / $FULL ))`
+
+if [[ `echo $BATTINFO | grep Discharging` && "$PERCENT" -lt "10" ]] ; then
+    DISPLAY=:0.0 /usr/bin/notify-send "low battery" "$BATTINFO"
+fi