These are my experiments using water and immersing an anode and cathode of a different material inside, to turn the calculator only needs 3 glases and the led 12 glases.
The LED for over 24 hours with the same intensity.
http://www.youtube.com/watch?v=vD1e6-MtTig (calcularot running on water)
http://www.youtube.com/watch?v=f8XWIiB84Lg (led on water)