We had seen how to change the battery status display on Mac OS X Lion. Mac users can change the display to Icon only or Time Remaining or Percentage. But for some reason if the menu bar does not show the battery status then you can enable it using the option provided as part of Energy Saver Preferences.
Click the Apple icon and select System Preferences from the menu list.
Navigate to Hardware section and click the Energy Saver option under System Preferences.
In the Energy Saver Preferences, mark the check box with label as Show battery status in menu bar. This would show the battery status in Menu bar on Mac system.