Aloha,
For your info, in case you don't already know- Cell Design is of primary importance.
Many are concerned with surface area but this is not of primary importance.
Many think that amps are important. Surface area and amps are relative.
Cell design is first. Too much surface area (or too little) can actually diminish production.
Same with amps, amps are not directly related to production.
For an example, you may wany to look at my project pages posted at oupower.com,
mrgalleria, Mr. G cell.
Flat plates have the disadvantage of electronically working against each other,
thus not providing a smooth flow of current.
Tubes have the disadvantage of having unequal surface areas.
Bill