The OP had some trouble posting this, so I did it for him...
http://forum.allaboutcircuits.com/showthread.php?t=54563
http://forum.allaboutcircuits.com/showthread.php?t=54563
Something like "theoretical maximum positive voltage".
The question in my mind is something like, you can add all the electrons you want and get higher and higher voltages, but is there a limit to how many electrons you can remove from a theoretical sphere in a theoretical non-leaky place? Seems to me there is a limit, but I don't even know if that is true.
The total charge is a function of the number of charged particles separated, the voltage is a function of distance betwen the separated charges as well.