[quote=@Willy Vereb]
<Snipped quote by MetalLover>It was found in the modern world already. It's called compact carbon-nanotube based hydrogen fuel cells.
Also by pure scaling off from the tank-mounted railguns we already should have the power source to feed 1-10kJ range railguns with relative ease.



[/quote]

Ok then, we can have hand-carried railguns, but they will not be as powerful as tank mounted railguns.