#!/bin/sh
mac="18:02:27:19:0A:31"
mac="${mac//:/_}"

stat=$(dbus-send --print-reply=literal --system --dest=org.bluez /org/bluez/hci0/dev_${mac} org.freedesktop.DBus.Properties.Get string:"org.bluez.Battery1" string:"Percentage" 2>/dev/null)

[[ -n $stat  ]] && awk '{print $3}' <<< $stat || exit