One of the biggest drawbacks of consumer-level drones like the DJI Phantom is the fly time for each battery charge. Extra batteries & chargers cost big bucks meaning most users are stuck waiting 5 hours to charge their drone battery so they can fly for less than 15 minutes.
Just now I had a low-tech idea to solve this problem with todays technology, with tradeoffs.
Why not have the drone plugged in to an air-to-ground power tether for hours of hover-time and short-distance fly-time? The only fly-time limit now is the ground-based power source & the drones mechanical condition. The tether is made of thin, visible (or camouflage) and lightweight electric wiring intertwined with some kind of rope/para-cord/or kite-line to reinforce the wires and make it snap resistant. The tether is stored in a retractable fashion for quick deployment and tangle-free use. The big trade-off being you can only fly the drone in a cone-shaped radius and in places where there little to no chance the tether won't snag against trees, power poles, buildings or other obstructions.
Yes, the weight of a hanging tether would put a payload on the drone but the additional energy needed is satisfied by the ground-based power supply. The power supply provides enough juice to charging the drones battery and fly the drone simultaneously. The drone still carries a battery, in case the ground based power supply is lost or the tether gets cut. In the event of a tangle, the tether has over-stress disconnect points every 10 meters or so; which are designed to disconnect with a sudden hard tug or overloading happens.
The drone could be fitted with a remote disconnect that has the drone come down to earth to disconnect the tether for 14 minutes of wireless flight, before returning to the tether spot to connect or be connected again; so the drone can continue flying. A fully automatic system to connect/disconnect the drones power tether could be an upgrade option.
Ideally the drone power supply module can use any 12v DC source, enabling people to fly their drones by drawing from their car battery.
Whoever turns this idea into a commercial product for consumer grade camera drones, please message me with the name of your company and ways to invest in your company.-- Dignium, Sep 30 2016 [+] suggest a quick release and a couple minutes worth of battery to avoid tangles.-- FlyingToaster, Sep 30 2016 If you only need your drone in a cone over your power supply maybe you should just raise a blimp, or a tower. Those drones are supposed to be delivering life-saving penicillin to suffering sailors at sea or dropping propaganda leaflets on jihadists.-- bungston, Sep 30 2016 This is a good idea.
Relatedly, I've often thought there would be a market for one of those electric human-carrying hoverboards that ran from a long cable. If I could hover around my garden for an hour I'd be happy.-- MaxwellBuchanan, Sep 30 2016 Hmm, why not just give up on leccy, and use .22 blanks to turn the props?-- not_morrison_rm, Sep 30 2016 Loud. Limited flight duration.-- MaxwellBuchanan, Sep 30 2016 A quadcopter can consume up to a kilowatt or two. Your wire needs to be thin so it's light, so the current can't be very high. Therefore the voltage needs to be high to get the necessary power, and that means you need either motors optimized for high voltages, or a boost converter on the ground and a buck converter on the aircraft.
There was a guy a century or so ago who built an electric airplane that was powered by a tether, for R&D purposes. You might look into that. I cannot refind it at the moment.-- notexactly, Oct 03 2016 Tethered electrically-powered helicopter trainers are Baked and KTE.-- 8th of 7, Oct 03 2016 random, halfbakery