OS X Lion: If an X appears on the battery icon in the menu bar
If the battery icon in the menu bar contains an X, either your computer does not recognize the battery or the battery is not properly installed in your portable computer.
- If a battery is fully charged, your computer may not recognize it. After you plug in your computer and let the battery charge for five minutes, the battery should be recognized.
Your battery can become fully drained if you use your computer unplugged until it puts itself to sleep or if you leave it in sleep mode for an extended period.
- If you can access the battery, remove it and then reinstall it. Refer to the manual that came with your computer for more information about properly installing the battery.
- If the battery icon in the menu bar still has an X in it, your Mac may need to be serviced.