Get batteries capacity percent.

def battery_percent(self):
        """Get batteries capacity percent."""
        if not batinfo_tag or not self.bat.stat:
            return []

        # Init the bsum (sum of percent)
        # and Loop over batteries (yes a computer could have more than 1 battery)
        bsum = 0
        for b in self.bat.stat:
            try:
                bsum += int(b.capacity)
            except ValueError:
                return []

        # Return the global percent
        return int(bsum / len(self.bat.stat))