I had much better results with a wall transformer.
I ran it for 15 minuts, and the mixture turned my ice tea from a dark tea color to something like miller lite.
It no longer tase like tea, but does taste like pool water.
The transformer is 9 v and 500ma.
So it looks like it's the current, and not the voltage that is needed.
I guess 2 lithum batteries can put out quite a bit more current than a nine volt.