I have expieremented with hydrogen before, but I couldnt store it. I would like to build a pressurized system that way I could store it in propane tanks.
It would be a GREAT load when your batteries are full, which I might try and do.
It's funny though when people hear about hydrogen they think "crazy dangerous stuff", when it's just like propane(not in power, but in handling/exploding). If you dont mix the oxygen with the gas, there is no boom.