Fuel cells might end up better than batteries if you consider the cost/lifetime of batteries. Energy density and safety are also valid considerations, the batteries are already at the limit of what you'd want to sit on top.
Hydrogen by itself has the energy density of zero. Batteries are nearing the energy density of high explosives (and for some types, such as Li-S, exceed it), and, unlike hydrogen, have all the components required for energy yield within micrometers of each other.
