Why battery-powered aircraft will never have significant range

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Vigilant1

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It's
www.air-atos.de has a neat all-electric......300km range, 100 km/hr, 3 hours, ....... that seems "pretty-significant" range to me!

It could be fun for tooling around the skies a little, but let's keep things in perspective as far as "pretty significant" performance. It cruises as fast as a 150cc scooter, and the scooter can carry twice as many people.
 

John.Roo

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www.air-atos.de has a neat all-electric......300km range, 100 km/hr, 3 hours, ....... that seems "pretty-significant" range to me!

I definitelly like the ATOS Wing idea, just..... the price.
This nice super light flying machines are usually really expensive.
Like Archaeopteryx - is nice, but self launch electric version = 89 500 EUR.
 

PredragVasic

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www.air-atos.de has a neat all-electric......300km range, 100 km/hr, 3 hours, ....... that seems "pretty-significant" range to me!
That ATOS doesn't really offer any stronger argument for battery-electric than any of the examples before. Its weight is lower than even some gliders, as is its maximum speed. It really isn't an airplane. It's essentially a powered glider.

With current battery technology, you can either have a powered glider with plenty of range, or a 2-seat LSA with much shorter range. It is simply not possible, for now, to shoehorn enough energy into the weight limits we currently have.

That said, as I had mentioned before, if the battery technology continues to develop at the same pace it had for the past 20 years (getting cheaper, lighter and smaller every year), in less than 10 years, it should reach the point where it will offer four times the current capacity with same weight and volume, at much lower cost. That should bring the inflection point, making battery-electric viable solution for more than just fringe use-cases.

Tesla Model S long-range battery pack has 100kWh and weighs over 1,300lbs. If that much energy can be packed into 350 lbs (approximately the weight of 60 gallons of avgas), we can begin to explore some cross-country ability for a common 2-seat, or even a lighter 2+2 (something like Glastar, Sling Tsi, or Jabiru). And with Tesla-type superchargers, those 100kWh can be recharged in an hour or so (and at Level 2, overnight).
 
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Pops

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We've got folks who believe that living near an electric power line is affecting their biology. Gonna be a tough sell to get them to drive on/near an inductive power transfer mechanism.
Especially if they have a lot of metal in their body as I do.
 

tspear

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@Rhino

I signed an NDA, but I know there have been a couple press releases about large flight schools executing purchase agreements for electric trainers.
The flight schools all figure about one to two hours between flights parked. And expect recharge to happen that fast.
We shall see if it happens.

Tim
 

Voidhawk9

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@Rhino
The flight schools all figure about one to two hours between flights parked. And expect recharge to happen that fast.
Interesting. In the major flight schools I worked for, 30-45 minutes between flights was more typical. Except during financial crises, anyway.
But I guess there schools have lower utilization, which should make it work.
 

Rhino

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Interesting. In the major flight schools I worked for, 30-45 minutes between flights was more typical. Except during financial crises, anyway.
But I guess there schools have lower utilization, which should make it work.
That's basically what I said earlier. It works if they only do one flight a day, or flights separated widely apart, but not for high utilization of aircraft.

I lost count of how many NDAs I signed. Most of them listed various monetary penalties and prison sentences. One had only two punishments listed, life in prison or death. That one got my attention! It was for something I did for Special Operations Command. Fortunately it was a one time deal. I never knew NDAs like that even existed until that Army Major handed it to me. The funny thing was it was given to me in the office of the wing commander at that base, who had to leave the room because he wasn't cleared for what we were saying.
 

John.Roo

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Training with electric airplanes is possible, it is kust necesary to keep on mind few details.

You will probably start the day with fully charged airplane. Landing should be done at remaining 10-15% of battery capacity. During de-briefing and pre-flight instructions pause you have to use fast part of cells charge curve - typically from approx. 10-85%. Makes no sense to charge to 100% because last 10-15% are very slow due to final cells balancing. So will be good to ballance cells overnight before another flying day.

Another point - temperature....
If battery is too hot you cannot start charging.
This can affect a lot length of pause between trainig flights.
Solution is of course temperature battery management but this is another installation weight.

Fast charge....
And temp. issue is here again... Too fast charging will heat up battery.
If you have Tesla and you use superchargers you know that temp. management has to do a lot of work during this operation.
Solution could be to have some "on ground" battery cooling system.

Each electric arplane is different.
My personal experience is with electric Phoenix so before last landing before re-charging I try to use min. power to land with as cold as possible battery. In this case is big advantage larger batery capacity and long wings :)

Training with electric airplanes is possible and in future will be necessary.
I am not that optimistic to expect that we will see big electric airliners in near future :)
However experience with electric propulsion during trainig will show to pilot important differences between elecric and combustion propulsion systems.
 

dog

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Training with electric airplanes is possible, it is kust necesary to keep on mind few details.

You will probably start the day with fully charged airplane. Landing should be done at remaining 10-15% of battery capacity. During de-briefing and pre-flight instructions pause you have to use fast part of cells charge curve - typically from approx. 10-85%. Makes no sense to charge to 100% because last 10-15% are very slow due to final cells balancing. So will be good to ballance cells overnight before another flying day.

Another point - temperature....
If battery is too hot you cannot start charging.
This can affect a lot length of pause between trainig flights.
Solution is of course temperature battery management but this is another installation weight.

Fast charge....
And temp. issue is here again... Too fast charging will heat up battery.
If you have Tesla and you use superchargers you know that temp. management has to do a lot of work during this operation.
Solution could be to have some "on ground" battery cooling system.

Each electric arplane is different.
My personal experience is with electric Phoenix so before last landing before re-charging I try to use min. power to land with as cold as possible battery. In this case is big advantage larger batery capacity and long wings :)

Training with electric airplanes is possible and in future will be necessary.
I am not that optimistic to expect that we will see big electric airliners in near future :)
However experience with electric propulsion during trainig will show to pilot important differences between elecric and combustion propulsion systems.
Cell balancing isnt absolutely nessesary on each charge cycle for lithium batteries.
Charging algorithims are advancing along with
battery chemical and physical characteristics.
And as we know,a flight school that is successful and growing will need to have reserve capacity, so sacrificing longest possible batterie life for an extra flight per day
is going to be an easy choice.
And it turns out that older batteries are safer,
statisticaly as most battery problems manifest
early in a batteries life.
Currently there is a rapid adoption of graphite
nano spheres as a material for anodes in lithium batteries, with the first nano graphite sphere production outside China begining in Australia this year.
 

BBerson

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Lessons could be 30 minutes instead of 1 hour. One hour is probably too much for a student anyway and just pads the schools profit.
 

Hot Wings

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Depends on what stage of the instruction the student is going through. The first lessons are probably best broken up into short periods, with the next lesson following soon after. Information overload is real.* Further into the course syllabus longer sessions allow more time to practice the mechanics and refine the performance of a particular task.

This is the reason that CFIs have to learn a little bit about how people learn. Too many CFIs apparently need a little more understanding of teaching/learning theory.

*I experienced it just a few weeks ago flying with my brother in his new to him 175 with a STOL kit. It may look like a 172 but I'd probably have to spend a few hour long solo sessions to get comfortable with it. Proficient - even longer. If it had a tail wheel and didn't look like a 172 I might be able to adapt faster?
 

BBerson

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Ten minutes works best for RC students. Spare battery charging from 50% to 80% during the flight for the next student.
 
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