Bash script for maintaining optimal battery charging range on a laptop

battery-alert.sh

#!/bin/bash

while true; do
  export DISPLAY=:0.0
  battery_level=$(acpi -b | grep -m1 -P -o '[0-9]+(?=%)' | awk '$1>0 { print $0; }')
  ac_power=$(acpi -a | cut -d' ' -f3 | cut -d- -f1)
  if [ "$ac_power" = "on" ]; then
    if [ "$battery_level" -ge 80 ]; then
      notify-send -u critical "Please unplug your AC adapter" "Battery level: ${battery_level}%" -i battery-full-charged
    fi
  else
    if [ "$battery_level" -le 30 ]; then
      notify-send -u critical "Please plug your AC adapter" "Battery level: ${battery_level}%" -i battery-caution
    fi
  fi
  sleep 60
done