Graviman:
Often the two technologies are combined to allow fuel cells to trickle charge LiPo batts in between demand peaks. For constant high power applications like helicopters this approach is of limited use, but LiPo will eventually give way to true high power to weight fuel cells. When will this happen? Eventually...
When will fusion reactors be used to generate electricity? For the last fifty years, it's been about fifteen years away from application, hasn't it?
As to power for a electric helicopter ... the latest article on graphene layers used to manufacture batteries looks promising.
Apparently, something like a 4:1 power stored to weight improvement over current best.
They say the introduction is around five years away ... but we shall see.
In re this prototype: you have a pure electrical power suppply, and your flight control commands are transmitted via electrical circuits.
Does anyone besides me see a problem with this? There is a non trivial problem with this when you get out of the laboratory.