My problem was once having selected Show Time or Show Percent in the menu bar battery status icon's drop down menu, I could not restore the battery status icon to it original state, i.e. showing neither time left or percent remaining.
Well, I'm not sure anyone else has this 'problem', but if you do prefer the
clean look of the battery icon without textual accompaniment, here's
how.
1) command-drag the battery status icon from the menu bar (or go to Energy Saver and hide the battery status using the tick box)
2) Open the following file with TextEdit
Users/<username>/Library/Preferences/com.apple.menuextra.battery.plist
It will look like this (or like this but with the YES and NO swapped).
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist SYSTEM "file://localhost/System/Library/DTDs/PropertyList.dtd">
<plist version="0.9">
<dict>
<key>ShowPercent</key>
<string>YES</string>
<key>ShowTime</key>
<string>NO</string>
</dict>
</plist>
Change the YES to NO.
Save the file.
3) Restore the battery status icon from Energy Saver (in System Preferences) by checking the tick box for 'Show battery status in menu bar'
4) Hey presto! You now have the battery icon (which visual indicates the amount of battery life left, even going into the red when apprpriate) without the otiose per centage or time remaining information. Just how I like it

.