Update: Better battery script (using upower instead of acpi).

scripts/battery

@@ -9,27 +9,25 @@ done
 dir_icons="/usr/local/bin/icons"
 
 # notify when below this percentage
-warning_level=15
+warning_level=20
 
 # how often to check battery status, in minutes
 check_interval=1
 
 while true; do
-  battery_level=$(acpi -b \
-    | cut -d, -f2 | cut --characters=2,3,4 \
-    | sed 's/%//g')
-  charging=$(acpi -b | grep -c "charging")
-
-  # when battery is low, and not already charging
-  if [ "$battery_level" -lt "$warning_level" ] &&
-     [ "$charging" -eq 0 ]
+  battery_level=$(upower -i $(upower -e | grep BAT) | grep -E "percentage" | sed 's/[^0-9]//g')
+  discharging=$(upower -i $(upower -e | grep BAT) | grep -E "state" | grep -c "discharging")
+  time_to_empty=$(upower -i $(upower -e | grep BAT) | grep -E "time to empty" | sed 's/[^0-9,.]//g')
+                                                 
+  # check if battery is low and discharging
+  if [ "$battery_level" -lt "$warning_level" ] && [ "$discharging" -eq 1 ]    
   then
     dunstify -a "Battery" \
         "Low battery: ${battery_level}%" \
-        "Battery is running low" \
+        "Battery is low ($time_to_empty minutes left)" \
         -r 100 \
         -i $dir_icons/battery.svg
   fi
 
   sleep ${check_interval}m
-done
+done