Electrolysis of water

Hey /sci/,
Is carrying around a battery and a liter of water an alternative to carrying around a helium container?

A liter of water makes about 1200 liters of ideal H2 at STP.

>>8
That's not what I last heard, nor what wikipedia says (definitively), but sounds plausible.

I'll make a note of not bailing from airships and such until the very last minute.