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12-16-2020, 08:52 AM
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Join Date: Oct 2009
Location: Sidney, BC, Canada
Posts: 4,415
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Quote:
Originally Posted by sailvi767
The test Beaver used a Lithium ion battery pack.
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I had to go back and find the pilot's statement to confirm, but you're right! Here's what he said:
Quote:
Originally Posted by HarbourAir
“What certainly hasn’t been done before is to fill a Beaver’s cabin with lithium-ion batteries, taking the plane to its gross weight. As a technology demonstrator, this eBeaver isn’t carrying passengers — there isn’t room — and will only have a 15-minute endurance with a 25-minute reserve.
These are batteries that NASA is using, but they’re not batteries that we’d use if we were going to try and make it economical to fly today, because they’re very low in watt-hours per kilogram...”
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The takeaway is that they used batteries that were nowhere near the current technology standard. Moving to a Tesla-style pack that optimizes use of space better would cut the size in half. And moving to newer battery tech would cut it in half again.
__________________
Rob Prior
1996 RV-6 "Tweety" C-FRBP (formerly N196RV)
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12-16-2020, 09:33 AM
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Join Date: Nov 2019
Location: Boulder, CO
Posts: 418
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Quote:
Originally Posted by Cumulo
https://www.cnet.com/roadshow/review...i-nexo-review/
The Hyundia Nexo. Hydrogen fuel cell/ lithium battery. 161 HP, 291 ft lbs torque. Cool.
Buy one(~$60K), strip the motor, fuel cell and battery, add bulbous tip tanks for the bulky hydrogen fuel and fly 1500 miles. We're THERE! Electric flight. 
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An aircraft full of hydrogen. Nothing has ever gone wrong with that.
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12-17-2020, 09:54 AM
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Join Date: Feb 2015
Location: Basel, Switzerland
Posts: 260
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There is a company in Switzerland building a hybrig aircraft with a Rotax for cruise and charging and a battery for near airport operations.
http://www.smartflyer.ch/aircraft/
__________________
-----------------------------------
Yves - Basel, Switzerland
RV-8 #83458 HB-YUA
Donation 2020 done
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12-17-2020, 10:17 AM
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Join Date: Dec 2009
Location: Boulder, CO
Posts: 5,572
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I once worked on the design of a hydrogen fuel tank for a hydrogen-powered airplane. The entire fuselage shape was designed to accommodate the tank, which was relatively large for the mass of fuel it contained, hydrogen being low-density. The volumetric energy density of hydrogen is low.
The tank itself was significantly more complex and difficult than a liquid fuel tank would have been, even though (I think) it might have been fueled with liquid hydrogen. As the hydrogen got used, it changed to a gas. Fuel tanks and airplanes being what they are, the tank needed to be able to withstand but internal pressure and a vacuum, as well as the normal flight loads.
Bottom line is that it'll be a while before hydrogen fuel can be used on our kit airplanes.
Dave
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12-17-2020, 02:51 PM
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Join Date: Nov 2019
Location: Boulder, CO
Posts: 418
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Quote:
Originally Posted by David Paule
Fuel tanks and airplanes being what they are, the tank needed to be able to withstand but internal pressure and a vacuum, as well as the normal flight loads.
Bottom line is that it'll be a while before hydrogen fuel can be used on our kit airplanes.
Dave
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I think Dave wins the prize for understatement of the year. Given how much trouble people have building Van's tanks that are able to withstand 1 PSI, and how many QB tanks even come from the factory with leaks, whatever pressures Dave was using in his experimental planes are well out of reach of our meager rivet-and-proseal skills.
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12-17-2020, 03:37 PM
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Join Date: Dec 2009
Location: Boulder, CO
Posts: 5,572
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While the airplane would be considered experimental if we built it, it was developed for a governmental entity. I was fairly far down that line, being a consultant to a contractor to the company that was developing the airframe.
One thing I remembered was that my client had difficulty with both the physical construction of the tank and the verification of it. They needed to create some dedicated test equipment, even beyond the tank. I don't know how that project finished because I retired right after my phase was done. But later I did see a photo of the airplane in Aviation Week, flying. I have no knowledge of whether the tank I worked on was used. Other changes were evident.
Really, this just ain't gonna happen in our world. Stick with liquid fuels and think about electricity.
Dave
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12-17-2020, 04:53 PM
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Join Date: Jan 2016
Location: Southwest, USA
Posts: 2,606
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low tech
I think a really long extension cord is lighter than current batteries for the same amount of endurance.
__________________
John S
WARNING! Information presented in this post is my opinion. All users of info have sole responsibility for determining accuracy or suitability for their use.
Dues paid 2023, worth every penny
RV9A- Status:
98% done, 2% left to go
To Go: wing mounting, engine baffles, wing tips, move to airport
www.pilotjohnsrv9.blogspot.com
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12-17-2020, 05:26 PM
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VAF Moderator / Line Boy
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Join Date: Jan 2005
Location: Dayton, NV
Posts: 13,309
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Quote:
Originally Posted by PilotjohnS
I think a really long extension cord is lighter than current batteries for the same amount of endurance.
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Well I guess that would return many of us to our aviation roots....U-Control!! 
__________________
Paul F. Dye
Editor at Large - KITPLANES Magazine
RV-8 - N188PD - "Valkyrie"
RV-6 (By Marriage) - N164MS - "Mikey"
RV-3B - N13PL - "Tsamsiyu"
A&P, EAA Tech Counselor/Flight Advisor
Dayton Valley Airpark (A34)
http://Ironflight.com
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12-18-2020, 07:40 AM
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Join Date: Sep 2007
Location: Central IL
Posts: 6,916
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Quote:
Originally Posted by Ironflight
Well I guess that would return many of us to our aviation roots....U-Control!! 
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But don't cross the streams!!!
__________________
Bill
RV-7
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12-18-2020, 02:13 PM
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Join Date: Feb 2020
Location: Oswego, IL
Posts: 19
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One thing I haven't seen discussed much WRT to electric-powered aircraft is cooling drag. If you're cruising at 150HP and 33% efficiency on an ICE, you have to dissipate 300HP worth of heat. Cruise at 150HP with an electric motor, and you're dissipating somewhere in the region of 15HP of heat. If cooling drag accounts for about 7% of all drag, it's not a huge percentage, but it does move the needle a bit.
On the subject of hybrid engines, I'd love to see Toyota build one. The Prius hybrid systems have a very good reputation for reliability.
But what I'd *really* like to see is a diesel-electric fuel cell system. You'd get the range and speedy refueling of a traditional aircraft, the efficiency and lower cooling drag of electric motors, and the low cost of Jet-A.
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