RE; "Why on earth...." - missing the point
I'm sure the point is that whilst a battery is the preferred method for storing and transporting electricity, the fuel cell will provide an extra battery life "boost" alongside the traditional storage methods, for long journeys and extended stays in areas without electricity.
At least, that's what I've always thought, and indeed how it would be most useful... right? Fuel cells would be impractical for everyday use, but would excel in the situations i mentioned above.