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Tesla Electric powered RV

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I know there many very talented people on this forum. Someone must have thought of putting a Tesla motor, inverter, controller, and batteries in an RV.
Just the motor, for example weights only 70 lbs and puts out 362 hp. Although it’s seems some of the numbers differ on the internet, they all are in the same ballpark. If Bye aircraft with their Eflyer 2 can fly for 3 1/2 hours , the Tesla setup
In an RV might be interesting?
Maybe someone has already suggested this, hope this isn’t a repeat.
Thanks
Chuck
 
I've been thinking a lot about it. Biggest problem I see is a reliable reduction drive or finding a motor that will run efficiently enough at 2500rpm.

My math says about 3 1/2 total flight time using 81670 batteries the same amount of batteries in weight as the RV-14 currently has in fuel so really only about 3 hours safely.

The new packs in the Model 3 and Y are 2170's would probably add another 30 minutes, haven't done the math.

Then the problem is charging .. since there are no level 2 or 3 chargers at airports .. having to charge at least overnight with an AC adapter for every 3 hours of flying .. which basically kills the idea for anything other than novelty.

But the novelty would be cool :p :D
 
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The Tesla motor makes 362hp, but at what RPM? 362hp is way too much for all of the RV models. How much power does it make in the 2200-2700rpm range?

Another question is continuous output and cooling. Can the engine handle that high load and electrical current for long duration? A Tesla, while great when accelerating that power isn't used very often. A car operated in a legal fashion can't use much more than about 50hp continuously. An RV10 would need about 220hp continuous when climbing and 200hp is around 75% of 260hp for cruise.
 
362 off an IC engine is too much, it depends on what is the limiting factor. The electric motor will make much smoother power without the impulse vibration that a gas engine would create. On the flip side since they come up to 100% torque almost instantly you would probably need to limit the spinup torque in software.

I can't wait, lots of issues around noise and land use go away with electric aircraft. The drive systems have far fewer moving parts and make turbines look horribly unreliable.

And best of all, power is constant so you get some outrageous cruise speeds at high altitude.
 
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I know a guy in the middle of building an RV-8 that is going to put an electric motor in it. He's waiting for some improvements in battery technology. Basically, he will be able to take off, go do some 30 minutes of aerobatics and come back and land with 30 minutes of reserve. Definitely not a cross country machine.
 
The current Tesla model 3 battery weighs about 1060 lbs. Given a sustained requirement for 150 HP inflight I suspect that battery would be good for 45 minutes. Just not going to work with current batteries.
 
Its definitely the future. The big two have tried to stymy any innovation in Internal combustion engine tech for last 20-30 years. Each new airframe designed around their existing power plants has assisted them in this.

However i see pipistrel have anew version of their panther coming out with a hybrid battery 915is power plant capable of 215 knts. Also companies like https://www.magnix.aero are creating powerful electric motors that weigh 1/10 of similar ICE power plant.
 
Another requirement for electric flight is going to be quick-change battery packs - no way will we be able to charge them fast enough to be useful for real flight. You would have to handle battery packs just like scuba tanks - drop off empties and pick up full ones - and the FBO's will have to invest in keeping a few packs on hand and charging them. The costs there are not inconsiderable.
 
Trouble in this here city

The trouble with electric airplanes are their landing weight is the same as their takeoff weight. This eliminates electric power for airliners with present technology
 
OHHH keep going about how wonderful electric flight is......

popcorn.gif




OK, bit of sarcasm on my part, but folks need to be defining the mission first, just like any other discussion on what to build or how to equip it.

Electric flight may be fine for some limited uses------as it stands at this time. Who knows what the future will bring?

To be useful for many folks it needs to improve a lot. How far can you fly in a single day cross country compared to a gasoline powered aircraft? At the same speed and load?

Biggies for me are flight time, charge time, and availability of locations for getting charged. And cost.
 
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It's going to be a while until we get to travel in electric planes mostly because of charging infrastructure, but having a fun plane to do some aerobatics in is not that far off. Acro planes don't have a lot of fuel to begin with so flight times would be fairly easy to match with electric power. You also can't be doing that for 3 hours, 30 minutes is plenty.
It might be weird though to zip around pulling Gs without the engine noise. :)
 
A glass of my favorite drink in, so I'll bite. I am a little familiar with battery and electric motor technology. Is it even possible for it to come close? IC engines from nearly the beginning were enough to work in airplanes, and they were very crude.
Can the technology possibly get there? There are limits to IC engines, I don't see efficiencies getting much better than what we have today. Range and turn around time are the two issues I see will be hard to solve for electric airplanes. I'd love to have a near silent airplane to go bend around for an hour, but I would never give up the range and turn around time of an IC engine.
 
I can see some sort of hybrid working.

Both powerplants for takeoff.

One of them for cruise. Which one depends on conditions.
 
Tesla

Upside; No more lean of peak arguments, No carb ice, No fouled plugs, No leaky RV tanks, No more vapor lock. No more EarthX vs Odyssey debates. The list goes on and on.. If the RC plane world is any indication it’s hopefully coming soon
 
Electric power for aerobatics might work at your home field. Blast off for a half hr aero flight. But what if you want to travel to a contest? Electric does work for sailplanes as a sustainer motor but you still need a tow if you want much power left for a potential return if lift fails.
 
I think something like a hybrid or hydrogen power makes more sense in a plane. Diesel hybrid could use Jet A, or hydrogen could still allow for similar infrastructure and the ability to quickly refuel.
 
Upside; No more lean of peak arguments, No carb ice, No fouled plugs, No leaky RV tanks, No more vapor lock. No more EarthX vs Odyssey debates.

Well.... It could have a leaky tank (battery), but no MMO discussion. What about the primer??? :confused:

-Marc
 
The electric motors in a Tesla are constant torque up to rated speed. It will make 200 HP at about 3500 RPM for the rear S motor. Google Tesla motor torque curve.

https://www.quantumscape.com Just announced the new battery - check the stock price increase. They have a nice video on the technology. Claims full charge in 15 min , 50% increase in energy density.

240 lbs of fuel takes an RV7 700nm, but even the solid state battery won't do that.

If at altitude and the battery goes flat point the nose down and recharge, some anyway. Or set a neutral torque speed and glide with no prop drag.

By then it will auto land anyway. No worries.

Maybe, since the motor speeds are up to 15-18k then it would be best for a nice ducted fan, like the Sonex jet. That could be real fun to blast up to 25,000ft and coast for a while. 350HP zoooooom.

If I was wishing for something more attainable it would be a liquid cooled reciprocating engine, gasoline direct injection (500 bar), turbocharged/compounded (with electric spool), 11-13 Cr, and operate on mogas with half the fuel burn of todays engines (50% OTE), and twice the life. Oh - same or better power/weight ratio. Likely a steel piston. Electric compound allows electric air-conditioning. Maybe the FAA would underwrite funding for a common core development just to get rid of lead. But this is off topic. :-(
 
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When you scale up RC planes to something we fit in, all things do not scale up. Otherwise we'd have an IC engine that would allow me climb straight up and hover with the prop size I have now. I don't think RC airplanes are indicators as much as we might like.
 
Really, the problem comes down to just charging. All the other stuff is mostly figured out. The only reason Tesla's make sense is that they are super easy and really fast to charge while on trips due to Tesla's "Supercharger" network. The charging at home (or in the hangar) is easy, it's the trips that are the problem.
 
The solid state stuff looks promising, but still needs to be scaled up. I think the energy density problem still exist, as far as keeping range close. But again the solid state stuff might work for that as well.
 
The charging availability could be worked out pretty easy in many of the mid size airports. We put them in at all of our apartments and most of our developments. They are not that expensive and we use a credit card and app to bill for the charge. Just because they are not expensive to install, they will not pay for themselves from charge revenue. We consider it an amenity for our residents or tenants so the cost is absorbed into rent.

If you could set them up close to car parking they could be used for both. Maybe it could become a draw for restaurant. They could get listed on the charging station app and maybe get people traveling to stop by, charge, and get a hamburger.

But, until there are elect planes flying around, not much upside to having charging stations.
 
Interesting

I have a Tesla Model 3. (FYI, that's as Green as I get. I'm a Ford guy. I got it for my 106 mi RT drive for work). The car absolutely hauls A$$. But it is just loping along at highway speeds. Battery consumption is spot on. Absolutely the finest car I've ever owned. I'm old so I've had a bunch!!!

Now for planes, the batteries are very heavy. The CG would be a major problem and, as has been mentioned, where ya going to charge it!! My 220 home charger charges at a rate of 40 mph. I have seen Super Chargers hit 500 mph charge rate. My home charger costs about $10 a month to operate.

Electric is coming for sure. The entire practicality comes from addressing the above listed issues. When it happens it will be great. Think about it, you'll likely be able to get a power package for $20K or so with unlimited fuel!!
 
Really, the problem comes down to just charging. All the other stuff is mostly figured out. The only reason Tesla's make sense is that they are super easy and really fast to charge while on trips due to Tesla's "Supercharger" network. The charging at home (or in the hangar) is easy, it's the trips that are the problem.

I wish I could find a copy of the one article on electric aircraft power. It was really good. The current Tesla batteries would have to weigh somewhere in the 4000 lb range to provide 3 hour flight time at 150 HP and 70F temps assuming you don’t heat the aircraft. In 10 to 15 years they might get that down to 1500 lbs. it could take a lot longer. The batteries also have to be conditioned meaning you need a cooling and heating system for the battery pack to get optimum output and input and that adds significant additional weight. They hate cold and range is dramatically reduced with cold temps. The current Tesla’s see a 30% loss of range at 20F temps with a heated pack. Tesla recommends that you keep the batteries between 10 and 90% charge or battery life will be impacted further reducing range. Supercharging again reduces the life of the battery. Tesla almost always makes supercharging claims for adding a specific amount of miles not to full charge. This is because the last 20% of charge takes far longer than the middle 50%. I am 62 and don’t expect to live long enough for meaningful cross country light aircraft to become battery powered. One last point is cost. Tesla is very closed mouth on battery costs but the current 75KW battery in the 3 and Y models is about 150.00 per kilowatt. The needed 300 KW pack will be 45,000 at today’s rates plus the cost of the conditioning and BMS system plus profit margin for sales. I am guessing 60-70,000 per pack to the consumer. Tesla has stated they think the can produce batteries at 100.00 per kilowatt in 3 years. That is however the actual cost to produce not market price.
 
Flying around with that much energy able to release in a short period of time (think either thermal runaway or catastrophic failure in a crash) gives me pause. Gasoline is energy dense, but it requires oxygen to release energy. Batteries do not...
 
Everyone has about 15 years to work this out. I received word last week that Lycoming has started building my engine.

2,000 hours down the road, I see myself at overhaul time replacing the engine and the gas tanks with a motor and batteries.

So, figure first flight late 2021. 100-200 hours a year.... By 2035 I trust that someone will have worked all of this out and I can make a simple swap.

8%-10% improvement in energy density per year means about a 300%-400% aggregate increase by then. Which is plenty for my needs, thanks!
 
won't happen

Bad, bad old arithmetic. It takes the fun out of everything, even my longing for an imagined quiet, comfortable electric airplane.

IC engine ~36% efficient (Carnot, another bad hombre in the world of reality)
electric motor ~90% efficient

Efficiency advantage of electric motor conversion of energy verses internal combustion engine = 2.5 times more output per energy input. Looks good so far.

Oh,oh.

gasoline energy =12.06 KwH/Kg
battery energy = 0.20 KwH/Kg (best lithium tech readily available today)

That's a weight to energy ratio ~60 to 1 in favor of gasoline!

Then, even with the efficient electric motor, the weight of the "electric fuel" will be 60/2.5 or 24 times heavier than gasoline. That would mean about 1500 lbs of "fuel" for a 200 mile RV hop. Not going to happen, likely ever.

That's the arithmetic and the way I see it. Maybe some short range, sailplane-like specialty aircraft are or will be within engineering reach, but batteries as a source of stored energy as a general replacement for liquid fuel in aircraft is a pipe-dream.

Ron
 
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Flying around with that much energy able to release in a short period of time (think either thermal runaway or catastrophic failure in a crash) gives me pause. Gasoline is energy dense, but it requires oxygen to release energy. Batteries do not...

Rarer than oxygen is the needed ignition source......................:D
 
Electric airplanes are getting tantalizingly close to a commercial breakthrough

Click bait title for sure but some merit...

For $140,000, you can fly your own electric airplane. The Slovenian company Pipistrel sells the Alpha Electro, the first electric aircraft certified as airworthy by the Federal Aviation Administration (FAA) in 2018. It’s a welterweight at just 811 pounds (368 kilograms), powered by a 21 kWh battery pack—about one-fifth the power of what you’d find in a Tesla Model S. For about 90 minutes, the pilot training plane will keep you and a companion aloft without burning a drop of fossil fuel.


https://qz.com/1943592/electric-air...es, 2020,milestone year for electric aviation.
 
Classic case of NIMBY

without burning a drop of fossil fuel.

Other than at the power plant that generates the electricity to charge the battery.

IMG-0738-800x450.jpg
 
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Other than at the power plant that generates the electricity to charge the battery.

The big debate here is often misleading .. you do have to generate the electricity somehow, true, but the big difference is using the electricity is considerably more efficient than gasoline .. so in the case of electric cars you can get over 4x the driven miles on the same amount of fossil fuels .. or rather support 4-5 more cars on the road without increasing fossil fuel usage ..
 
There is a good article in the July 2019 Sport Aviation magazine (yes, I'm a little behind in my reading) called Electrified by the owner/builder of an electric Kit Fox. The engine is from an electric motorcycle with gear reduction and two sets of batteries (for CG purposes).
 
The big debate here is often misleading .. you do have to generate the electricity somehow, true, but the big difference is using the electricity is considerably more efficient than gasoline .. so in the case of electric cars you can get over 4x the driven miles on the same amount of fossil fuels .. or rather support 4-5 more cars on the road without increasing fossil fuel usage ..

Big assumptions, here but this statement can't be validated. How was the electricity generated? No one can claim that answer with any certainty.

Fossil plant? Roughly the same amount of fuel would be used, before conversion and transmission losses. The "distributed" IC engine is an overall better use of resources.

Simple Cycle gas turbine? Close to the same, above.

Combined cycle plant? The electrical vehicle is easily a better use of resources for regarding aircraft but close to dead even for cars.

Wind or Solar? The economics are full of lies. If they were made to have a reliable supply, your associated electric bill would be more than your mortgage payment.

Hydro? Nothing can touch it's cost of generation if back-up resources are not included. Droughts do happen and reservoir levels do drop but it's at least predictable so the spot market stays flatter.

Electric vehicles including their related wattage sources are typically better regarding atmosphere pollution. Terrestrial pollution? Sorry but not really.

I can draw a box around anything to promote its merits as people who promote such do.

Would any of you VAF'ers like to invest in the new panocea known as the Hydrogen economy? There's a lot of people who would love to have your money.
 
Big assumptions, here but this statement can't be validated. How was the electricity generated? No one can claim that answer with any certainty.

Fossil plant? Roughly the same amount of fuel would be used, before conversion and transmission losses. The "distributed" IC engine is an overall better use of resources.

Simple Cycle gas turbine? Close to the same, above.

Combined cycle plant? The electrical vehicle is easily a better use of resources for regarding aircraft but close to dead even for cars.

Wind or Solar? The economics are full of lies. If they were made to have a reliable supply, your associated electric bill would be more than your mortgage payment.

Hydro? Nothing can touch it's cost of generation if back-up resources are not included. Droughts do happen and reservoir levels do drop but it's at least predictable so the spot market stays flatter.

Electric vehicles including their related wattage sources are typically better regarding atmosphere pollution. Terrestrial pollution? Sorry but not really.

I can draw a box around anything to promote its merits as people who promote such do.

We have two Teslas and spend about $50/month fueling them instead of $250 for petro .. just sayin' .. but there's some solid research out there if you stay away from the crazies ..
 
We have two Teslas and spend about $50/month fueling them instead of $250 for petro .. just sayin' .. but there's some solid research out there if you stay away from the crazies ..

Don’t get me wrong. I’m a big fan of Tesla. That technology and related economics don’t translate to aviation.

As for your comparison, you are probably, indirectly burning natural gas in your Tesla by way of the power grid. The heating values of natural gas and gasoline are in the same ballpark. The relative economics come down to cost/BTU of fuel; natural gas versus gasoline. As you initially stated, it’s misleading.

Adding to my opinion here. I said I was a fan of Tesla. Going to add that I'm a fan of Musk as well. I can't think of anyone else that totally disrupted two major markets in a relatively short life; automotive and space launch. Opinion over.
 
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Not yet, for the mission you may want

I know there many very talented people on this forum. Someone must have thought of putting a Tesla motor, inverter, controller, and batteries in an RV.
Just the motor, for example weights only 70 lbs and puts out 362 hp. Although it’s seems some of the numbers differ on the internet, they all are in the same ballpark. If Bye aircraft with their Eflyer 2 can fly for 3 1/2 hours , the Tesla setup
In an RV might be interesting?
Maybe someone has already suggested this, hope this isn’t a repeat.
Thanks
Chuck

I worked as Sr Engineering Manager for Powertrain at Tesla's Fremont plant in charge of all of the automation to build Model S/X modules, packs, small drive (SDU), large drive (LDU), chargers, center consoles, etc. I also worked in Manufacturing Engineering at Alta Motors doing powertrain as well as main line assembly before they closed their doors. I have more than a casual understanding of cylindrical cell lithium batteries and high power-density electric motors.

The numbers you quoted above are not correct, or at least a little misleading. None of the Tesla motors (M S/X LDU, SDU, or 3DU) weigh 70 pounds. Just the rotor and stator casing, perhaps. But once you add the two stage reduction units, inverters, and other required bits, they weigh considerably more than twice that. Close to 3x, actually. More for the LDU.

It is important to understand that at highway speed the motor in a Tesla (and pretty much any EV) is spinning relatively quickly. The reduction ratio on a Tesla two-stage gearbox is between 8.2 and 9.3:1, depending on the model. So while you are cruising down the highway at 60 MPH and your wheels are spinning at roughly 730 RPM, your motor is closer to 6800 RPM. You would need to accommodate some level of gear reduction to adapt a motor spinning that fast to a propeller. Also, you should understand that while horsepower numbers are fun to throw around, for an EV you will basically never actually attain that maximum value. As stated previously, the torque curve is basically flat from zero RPM. That means you do not actually achieve the headline horsepower value until very high RPM. So while the acceleration of an EV is incredible because the torque is available from a standstill, you are not actually feeling horsepower.

Next, the highest range Tesla Model S can achieve 402 miles per 100kWh pack. That means at 60 mph you are averaging just under 15kW. That translates to 20 HP. I cannot imagine actually flying along at max L/D for very long to keep the energy consumption down to a number close to that. Any increase in power is met with a proportional decrease in duration. In fact, the slope is worse than that because 18650 cells have lower total capacity ratings when you increase the C-rating discharge. Add to that that the power required to go faster on that side of the curve goes roughly cubically with airspeed. Things are getting worse very fast in terms of cruise speed and range now.

Next we can consider the mass of the battery. A single 18650 weighs right around 50grams. In a Tesla 100kWh pack you have 16*6*88 cells, or 8448 18650s, for just a cell mass of 930 pounds. On top of this you need the high current bus bars, wiring, cooling channels as associated fluid, pumps, etc. You have to have enough structure for the cells to not be compromised during G loads, as well as valves to deal with "thermal events" should your day go very, very poorly. You would be very lucky to get away with a final pack weight of 1000 pounds. Of course, you can reduce pack mass by reducing cells, which again increases the per-cell C-rate for a given load, so now you're back to trading mass for duration, and again you find yourself on the back side of the curve there.

At Alta we got away with significant weight savings by eliminating the fluid cooling system for the pack and using other thermal management techniques. This was to the detriment of overall cell lifespan, but for the use case of a high performance dirt bike, it was worth the tradeoff. We had a pack that was nominally 6kWh, and a motor capable of 40kW (53HP). Our pack alone was right around 65 pounds. But very few riders would pin the throttle and leave it there until the pack was empty, and we had thermal limiting to manage that if they tried.

This is not to say that electric aircraft are not happening. They are. The eVTOL category is full of vehicles that actually fly using these same technologies. They do so by managing the overall power profile over the duration of the flight very carefully, flying at max L/D for cruise at speeds that are in the neighborhood of 100mph, and have a total range of something less than 100 miles.

So, I think what you are asking for is going to happen sooner rather than later. But I do not think we are to a point where swapping powertrains on an E-AB and expecting Lycoming/Continental cruise speed and range is a thing.
 
Lots of numbers thrown about.

Here a reliable source for electricity and the US grid. Generally, for the total grid, it is about 35% efficient in conversion from fuel to electricity and a 5-6% loss getting it to the home. It has not changed much in the last 15 yrs.

Much analysis was done for determining industry investment and benefit for emissions. A good hybrid light duty class vehicle yields overall about 80% (Prius) the reduction benefit of an all electric (Electric Vehicle Symposiums). People are not rushing to get hybrids for all of their purchases, and they don't have the cross country limitations.

Even hybrids are being watered down. My wifes new RAV4 Hybrid has half the battery capacity of the Prius and an inferior powertrain for hybrid electric (compared to Prius). It has better acceleration than the standard which she liked. I liked the better mileage. Calculated cost per mile was better.
 
And the batteries deteriorate

I recently spoke to a Tesla owner in Denver who has a second home in Palm Springs. He mentioned that the battery capacity had deteriorated to the point that he cannot get more than 250 miles in a charge and does not drive it to Palm Springs. I don't know about you, but that is 550 miles too short for a days drive!
 
I recently spoke to a Tesla owner in Denver who has a second home in Palm Springs. He mentioned that the battery capacity had deteriorated to the point that he cannot get more than 250 miles in a charge and does not drive it to Palm Springs. I don't know about you, but that is 550 miles too short for a days drive!

Some details missing here they don't deteriorate that much .. sounds like he has a problem .. but just curious why he doesn't just stop and top off the batteries? There are 5 superchargers between Denver and Palm Springs ...

That's 1000 miles .. I would top off maybe 3 times .. 15-30 minutes per charge .. these chargers are generally located in nice areas with restaurants .. works out nicely on a trip like that :p
 
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I recently spoke to a Tesla owner in Denver who has a second home in Palm Springs. He mentioned that the battery capacity had deteriorated to the point that he cannot get more than 250 miles in a charge and does not drive it to Palm Springs. I don't know about you, but that is 550 miles too short for a days drive!

I drove double that one silly day. 1113 miles straight. Energy for the pickup truck came from gasoline that was easily refilled, and I was refilled by large coffees several times as well. I was driving to marry my wife, so significant motivation. I'd call it young and foolish, now almost 5 years later, it's a 2 day drive.

I have no doubt electric sport aircraft are coming, just not today. Well maybe technology demonstrator aircraft only. Certainty nothing practical or useful..yet. Look how far electric cars have come in the past 10 years, imagine what will happen in another 10 years.

Here's a great electric aircraft technology demonstrator: https://www.skiesmag.com/news/harbour-air-makes-history-with-electric-powered-beaver-flight/. Although it wasn't a Tesla motor.

As for how environmentally friendly electric is, that depends on the local power generation technology. My area is predominately hydro-electric. Much of Ontario is nuclear and hydro-electric. Some wind and solar, but that's not a major contributor and mostly a "feel good" government project. All the coal plants are long decommissioned and being demolished, with the environmental disaster the toxic coal ash causes. One was turned into "bio-fuel" for a few years, ran on basically saw dust and scrap from the lumber industry. Nuclear is by far the best option for many areas. Yes nuclear has it's risks, but looking statically, a coal plant ash pile is significantly more damaging than the extremely rare nuclear accident or the nuclear waste storage/disposal. Hydro-electric is great too, but only works in areas with a steady and consistent water supply. Basically Great Lakes watershed.
 
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Thomas Edison on Battery Technology

"The storage battery is, in my opinion, a catch-penny, a sensation, a mechanism for swindling by stocking companies. The storage battery is one of those peculiar things which appeal to the imagination, and no more perfect thing could be desired by stock swindlers than that very self-same thing."


Feb 17, 1883 - Thomas Edison
 
Also a Tesla owner. For electric vehicles at least, the question isn't "how much range can I get off of one charge" but "can I make the next charger". Since the number and locations of superchargers are limited, a 300 mile range and a 200 mile range in practice may have to stop at roughly the same superchargers anyways. As an owner of an M3 SR+, I get about 200~220 miles off one charge in practice, when charging to 100 percent for a road trip. I've made it cross country twice. The only time I hesitate is when doing road trips to national parks or other types of outdoor activity. When you're heading city to city like Denver to Palm Springs, the density of superchargers means a 250 mile range is more than enough to allow you to pick and choose which superchargers to stop at depending on food and entertainment options. And the network is only expanding from here.

Coming back to the airplane topic, if we use current tech, it's going to be all about charger density. EVs excel at around town travel, when you can return to your home/hangar at the night and charge up. Going cross country, there will be some owners who will gladly trade the extra time and stops for better performance and presumably, safer engines. Chicken and egg issue though. Without the powertrain, no one wants to build charging infrastructure at airports. Without the charging infrastructure, no one wants to buy electric planes.

Also, may not be cheap to build either. Tesla treats their network as marketing and doesn't expect it to turn a profit. EVgo and Electrify America prices are atrocious, something around 50 cents per KWH. This may indicate that charging infrastructure is much harder to make a profit off of than we thought, and that's with a much larger user base than general aviation.
 
Also a Tesla owner. For electric vehicles at least, the question isn't "how much range can I get off of one charge" but "can I make the next charger". Since the number and locations of superchargers are limited, a 300 mile range and a 200 mile range in practice may have to stop at roughly the same superchargers anyways. As an owner of an M3 SR+, I get about 200~220 miles off one charge in practice, when charging to 100 percent for a road trip. I've made it cross country twice. The only time I hesitate is when doing road trips to national parks or other types of outdoor activity. When you're heading city to city like Denver to Palm Springs, the density of superchargers means a 250 mile range is more than enough to allow you to pick and choose which superchargers to stop at depending on food and entertainment options. And the network is only expanding from here.

Coming back to the airplane topic, if we use current tech, it's going to be all about charger density. EVs excel at around town travel, when you can return to your home/hangar at the night and charge up. Going cross country, there will be some owners who will gladly trade the extra time and stops for better performance and presumably, safer engines. Chicken and egg issue though. Without the powertrain, no one wants to build charging infrastructure at airports. Without the charging infrastructure, no one wants to buy electric planes.

Also, may not be cheap to build either. Tesla treats their network as marketing and doesn't expect it to turn a profit. EVgo and Electrify America prices are atrocious, something around 50 cents per KWH. This may indicate that charging infrastructure is much harder to make a profit off of than we thought, and that's with a much larger user base than general aviation.

For the uninitiated ... SR+ means "Standard Range Plus" there are Long Range and Performance options as well ... as a comparison, my Performance S gets 350 miles if I go easy on it, 315'ish miles if I drive .. ahem .. cough cough .. "normal"
 
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We already know enough about aerodynamics to make very low-drag airplanes (the Eta sailplane exceeds 70:1), but the "normal" planform for a 2-seat sport aircraft or a 4-seat utility aircraft places a practical limit on what's achievable there. It's unlikely that technological advances will make airframes much better than they are now, they're probably pretty close to as good as they'll ever get.

We also already know enough about electric motors to get very high efficiency power transfer: Electric motors that are better than 95% efficient are readily available. No matter how much additional technology you develop, you're only going to close-out the residual 5%, and not move the needle very far; In efficiency terms, electric motors are probably near as good as they'll ever get.

So then we can look at the battery system. Plenty of people who know more about it than me have already weighed in on this thread. Current batteries are 0.2 - 0.3 wH/kg, which is a factor of 20-30 less than liquid petroleum fuel, so if you keep everything else constant, including the weight, converting an airplane from IC to electric will substantially reduce its endurance.

... which is consistent with what we see from, e.g., Pipistrel, where the Virus yields nearly 6 hours endurance as a gasoline aircraft, but is a 30 minute circuit trainer when it's battery-powered and sold as an Pipistrel Alpha Electro.

So to get an aircraft that's at least as capable as a current generation gasoline airplane, we'd need battery energy density (W/kg) to increase by something in the realm of 10x-15x. Maybe more, to trade off battery charge time vs fuel tank refill time on multi-leg trips, and to account for the extra weight of the cooling systems higher energy density will want.

I don't think we see that coming down the pike.

There are research batteries in labs, yet to be commercialized, that are maybe 2x as dense. Maybe we can theorize about another doubling on top of that, and suggest that it's feasible to expect 4x in the medium-long term future.

But is anyone seriously expecting 10x-15x improvement? We've been making batteries for 200 years, they've been through efficiency spurts already; Do we think there's much more to come?

I'm skeptical. I'd love to be wrong, but I don't realistically expect that I'll see practical general-purpose electric aircraft in my lifetime.

Niche purposes, like aerobatics, air racing, motorgliders, etc -- Sure. Even right now. I know a guy with an electric motorglider, and the instructor who sent me solo has an Alpha Electro, so it's definitely happening.

But general purpose? "Load the family on board and fly to a vacation" that we can do with our airplanes now? I just don't see it happening any time soon. The only gains left to be had are in relation to batteries, and the pace of advancement just isn't there.

- mark
 
Here's a great electric aircraft technology demonstrator: https://www.skiesmag.com/news/harbour-air-makes-history-with-electric-powered-beaver-flight/. Although it wasn't a Tesla motor.

First flight of the electric Beaver was now over a year ago, practically in my back yard. A big splash of publicity in magazines and local TV news and then...nothing. I haven't heard of it being flown since. This was a megabuck effort with lots of really smart people. The motor and motor controls were excellent. I wasn't there, but I heard a rumor that the payload of eBeaver was 190 lbs, ie. the pilot (normal empty weight 3000 lb, normal gross weight 5100 lb). In other words, all the payload was taken up by the batteries.

I think we'll be waiting a long time before the power density of batteries allows a commercial payload to be carried.
 
what you need is the best of both worlds. For example current technology allows about 300watts/kg in a battery. So if you install a 20kwhr battery weighing about 70kgs in a plane and a small electric motor to drive your prop you probably have enough stored power to get any RV home/safe landing under electric power alone.

Alongside this you install a 230kw AUDI diesel engine as used in A6. This weighs about the same as a lycoming 0 -360 or 390 and produces as much power as a IO 540 or more. This engine only job is to keep the battery charged full so it needs no special design features as an aircraft engine. It will also run on Jet A.

You are safe because if the engine stops working you have a full electric battery to get you to safe landing spot and electric motors have almost no moving parts so very unlikely to break down. The AUDI engine will be about $10-$15k the battery price is about $120 a kw at present so $2400 in this scenario and you will need an electric motor and some electronics to manage the whole shabang...another $2k.

So for less than $20k you have a jet A fueled battery electric aircraft powerplant with the safety of battery power to get you home if the diesel engine gives up.....all the stupid engine rebuilds and maintenance issues almost disappear overnight
 
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