[ZeroGravitas]

Yeah, I dont see how this hydrogen battery is a very good battery.

If they could get anywhere near lithium battery efficiency for a round trip then the breakthrough in fuel cell efficiency (and possibly also electrolyzer efficiency) required to do that would be the headline.

And if they can't, then they'd probably need to be implausibly low cost to make it worthwile, and they don't seem to be that either.

Maybe there's some way of using the waste heat that improves it? Still seems unlikely.

So just an expensive, awkward low efficiency battery, when cheap, commodity, high-efficiency batteries are available.