Quite a bit on what it takes to control a fuel cell stack in vehicle and stationary applications: www-personal.umich.edu/~annastef/FuelCellPdf/pukrushpan_thesis.pdf

I find it interesting to read that:

o To get the kind of highly variable "transient response" (change in power output) required for automotive applications, the author proposes using a chemical battery as part of the power management system, as the fuel cell system can't itself respond quickly enough.

o The control system is as much or more challenging than that of an internal combustion engine, requiring control of these sub-systems:

__ * Reactant (hydrogen) flow subsystem

__ * Heat and Temperature subsystem

__ * (pure distilled) Water Management subsystem

__ * Power management subsystem

__ * If not fueled by hydrogen, an on-board fuel processor subsystem to break the chosen carbon-based fuel down to hydrogen

With just hydrogen fuel, it still takes an air compressor, three heat exchangers (fuel temp, fuel cell stack heat extraction, compressed air heat extraction), an air humidifier, a water separator, a power converter, a chemical battery (and software of course, to implement the control system) to make it all work in vehicle applications.

If you have enough current and are willing to stuff enough charging hardware into the car, you can do a 60% charge in 5 minutes with today's technology. It's just a matter of waiting for that hardware to go down in price so you can stuff enough into the car to charge the whole battery pack in parallel. Some of that will be helped by investment and R&D. Most of that will happen through economies of scale and the marketplace.

But that said, fuel cells that can utilize natural gas or propane would be fierce competition. That would give you better energy density, greater range, and access to fuel is already widespread. Quick charging would be solved. The only question left is the cost of ownership of the fuel cells.