LINUX | Check the battery power

battery.sh

#!/bin/bash

#IF statment will use this var to notify user about low battery
LESS_THAN=70

#Interval in sec
INTERVAL=30

while true; 
do
	STR=$(upower -i /org/freedesktop/UPower/devices/battery_BAT0 | grep percentage)
	VALUE=${STR//[A-Z a : %]/}

	if [ $VALUE -lt $LESS_THAN ] ; then
		notify-send "Battery is low: $VALUE%"
	fi
	sleep $INTERVAL;
done