by Bob Boyce » Mon Jun 20, 2005 9:36 pm
It all depends on whether those 4 plates are connected as 2 parallel sets of plates, or if they are dividing a cell up into 3 compartments making a 3 cell series setup. In a series setup, the same current flow creates gas in multiple cells at the same time, so you get much more gas per watt consumed.
On automotive power, it takes 7 cells in series to bring the voltage per cell down into the lower end of the exothermic range. Cell voltages higher than that just makes waste heat.
Bob