Well that's the thing: fuel cells are batteries, just that you use water as your main resource instead of heavy metals. A major advantage since water costs near

Well that's the thing: fuel cells are batteries, just that you use water as your main resource instead of heavy metals. A major advantage since water costs nearly nothing and heavy metals cost a lot. You sometimes hear people make the argument that it's too inefficient, but from a purely theoretical point of view this shouldn't be case. Fuel cells and batteries should have very similar efficiency levels in the long run. If you buy into that concept, then it should be almost all fuel cells in the future, with other types of batteries playing an auxiliary role. > There are still major issues with hydrogen containment since it can leak out of just about everything (being the smallest atomic structure) Not really true anymore. We've made major advancements here, especially with newer tanks made out of carbon fiber and lined with HDPE. It's not something we have to worry about too much now. > and also many hydrogen systems are used as fuel-cells to produce electricity rather than combustion for physical force. In that case, a Tesla vehicle powered by hydrogen would just have a fuel-cell energy store but still retain the same electric drivetrain. They're nearly all like that. Fuel cell cars are basically electric cars with a fuel cell as the source of electricity. This is a huge win since you only need a small battery (or capacitor) for power smoothing and regenerative breaking, instead of having to lug a giant battery around.