I have seen hydrogen fuel cells power drones for 3 to 5 hours but most fuel cells on the market that i have seen are really overpriced!
I have also heard of goodenoughs new glass electrolyte battery coming out in a few years its suppose to have incredible specs.
Hybrid electric gas / battery powered drones also get great flight times down side is they are really loud and cause a lot of vibrations
When this stuff becomes mainstream its going to change the drone industry!
Are there any other forms of powering a drone similar to these?
Really need something with 3 to 5 times the effeciency of li-pos!