From the XDA Developers Forum, I have implemented [this solution](http://forum.xda-developers.com/showthread.php?t=1386112) successfully on my Samsung Galaxy S Epic 4G (with GingerBread.EI22 and also GingerBread.EL30), which has eliminated the "Battery fully charged. Unplug charger" notifications from my phone.  The solution offers the following three features:

 1. Stops the vibration.  
 2. Silences the sound.
 3. Prevents the screen from turning on in the middle of the night.



Best of all, you may choose to implement any (or ALL) of the three features above.  Good Luck!