batterynotifier.sh

#!/usr/bin/env bash
s=$(date +%s | cut -b1-13)
while true
do
    export DISPLAY=:0.0
    battery_percent=$(acpi -b | grep -P -o '[0-9]+(?=%)')
    if on_ac_power; then
        if [ "$battery_percent" -gt 90 ]; then
	    s=$(date +%s | cut -b1-13)
            notify-send -i notification-power-disconnected -t 6000 "Battery full." "Level: ${battery_percent}% "
        fi
    else 
    	if [ "$battery_percent" -lt 30 ]; then
		j=$(date +%s | cut -b1-13)
		p=$(expr $j - $s)
		o=$(date -d@$p -u +%H:%M:%S)
    		notify-send -i notification-battery-low -t 6000 "Connect to AC power." "Battery Uptime: ${o}"
		s=$(date +%s | cut -b1-13)
    	fi
    fi
    sleep 120 # (3 minutes)
done