Another Example of EV BS

[AH-1 Cobra Pilot]

https://www.ainonline.com/aviation-news/general-aviation/2022-04-28/pipistrel-seeking-faa-nod-electric-velis-trainer

Presuming the author meant kW-hr for the battery...

Let's see...at full power, the battery will only last 20 minutes, or if, as the article says, you can fly for one hour with reserves, you would have to take off and fly at 22% power with your 80hp engine.  Seriously?  Anyone want to try a takeoff using 18hp in this plane?  Does anyone here fly at 22% power in his/her Mooney?

Apparently, too many people cannot do the Math, blindly believe the BS they are fed, and/or are simply zealots for this electrification nonsense.

[Hank]

38 minutes ago, AH-1 Cobra Pilot said:

Apparently, too many people cannot do the Math . . . and are simply zealots for this electrification nonsense.

FTFY.

Math is hard. Most people are happy to let someone else do it for them and blindly accept the results.

Same for thinking . . . . .

[A64Pilot]

Well if it is a 60KW motor and we assume 20KWH battery, cause a 20KW battery doesn’t specify capacity, one would assume it has a 20 min endurance at 100% power.

But while you want it to be simple math, it’s not. For starters without a very good thermal management system it’s unlikely you could deplete the pack that quickly, it would overheat, and good thermal management systems are heavy so I bet it’s air cooled, possibly passive

Then there is peukerts law https://www.batterystuff.com/kb/tools/peukert-s-law-a-nerds-attempt-to-explain-battery-capacity.html

I didn’t try reading that but it essentially says the faster you discharge a battery, the less power you can get out of it, so for example good deep cycle lead acid batteries are capacity rated over a 20 hour discharge, cause you can get a lot more total power if drained over 20 hours than say 1. So without giving us a C rate of discharge saying 20KWH isn’t the whole truth either, not saying they are lying, just people want simple answers when in truth there may not be a simple answer, most big packs can’t tolerate a 1C discharge rate.

Then we have no idea of how much of that 60KW is needed for takeoff, nor what is used in the pattern or how long the thing is essentially gliding as I feel sure that’s what it for, circuit flight training. So depending how well it glides and it’s climb rate it may spend a lot of the pattern gliding.

But there are really only two possibilities, if your right then everyone already knows they can’t do but a couple of laps in the pattern as they already exist, or maybe Pipestrel aren’t a bunch of thieving liars? OK a third possibility everyone who has flown one has been sworn to secrecy. I think the real truth is like every other airplane it won’t quite meet marketing specs, but a better question may be how fast does the battery lose capacity, all batteries do, some much faster than others.

But somehow EV horsepower is different, my Tesla motor is only 150KW, or 201 HP (it’s the slow Tesla) yet it accelerates it’s over 3,600 lbs of mass to 60MPH in 5.3 sec

Some will say it’s due to torque, but as the hp formula is torque x RPM / 5252 it shouldn’t matter, but I know of no 200 hp 3600 lb ICE car that will accelerate that hard.

While I agree the useful electric airplanes aren’t close yet, electric will eventually replace ICE, whether you like it or not, everything except he batteries is already there

A few years ago I thought EV’s would go to stations and their battery pack would be swapped out by automation, sort of like renting propane tanks, I didn’t think batteries could be charged fast enough to work, but having driven a Tesla on a trip a few times and recharging to over 80% in 15 min or so, I see it can.

A better question I think is what kind of cycle life does this pack have, and what does a new one cost, what’s the warranty etc? Cause if they are using almost all of the capacity, it probably won’t last longer than a phone battery in cycles, and if you plan on cycling it say 5 times s day, then it may only last 1/5 as long as a phone battery or less.

Edited May 2, 2022 by A64Pilot

[Shadrach]

In addition to math, reading is a challenge as well....This plane has been flying in Europe for over 5 years. It was designed from the outset for pattern work and has proven itself able to replicate the mission many of us accepted in our early training.  It is designed to climb to pattern altitude at >1000FPM, throttle back to low power settings for downwind, base and approach. At 27KW airspeed is >80kts.  

It's been more than 20 years but I have fond memories of doing "circuits and bumps" in the Indiana summer while honing my skills in a 1966 C150F.  This thing has about 3X the climb of a C150 in August.  Perhaps new pilots will learn to be more judicious with energy management with a battery meter to monitor.

This reads like you guys are mischaracterizing this machine so that you can $hit all over EVs.  As it stands currently, it's a viable training aircraft and I am sure endurance will improve.

 

Edited May 3, 2022 by Shadrach

[Shadrach]

39 minutes ago, A64Pilot said:

Well if it is a 60KW motor and we assume 20KWH battery, cause a 20KW battery doesn’t specify capacity, one would assume it has a 20 min endurance at 100% power.

But while you want it to be simple math, it’s not. For starters without a very good thermal management system it’s unlikely you could deplete the pack that quickly, it would overheat, and good thermal management systems are heavy so I bet it’s air cooled, possibly passive

Then there is peukerts law https://www.batterystuff.com/kb/tools/peukert-s-law-a-nerds-attempt-to-explain-battery-capacity.html

I didn’t try reading that but it essentially says the faster you discharge a battery, the less power you can get out of it, so for example good deep cycle lead acid batteries are capacity rated over a 20 hour discharge, cause you can get a lot more total power if drained over 20 hours than say 1. So without giving us a C rate of discharge saying 20KWH isn’t the whole truth either, not saying they are lying, just people want simple answers when in truth there may not be a simple answer, most big packs can’t tolerate a 1C discharge rate.

Then we have no idea of how much of that 60KW is needed for takeoff, nor what is used in the pattern or how long the thing is essentially gliding as I feel sure that’s what it for, circuit flight training.

But there are really only two possibilities, if your right then everyone already knows they can’t do but a couple of laps in the pattern as they already exist, or maybe Pipestrel aren’t a bunch of thriving liars? OK a third possibility everyone who has flown one has been sworn to secrecy. I think the real truth is like every other airplane it won’t quite meet marketing specs, but a better question may be how fast does the battery lose capacity, all batteries do, some much faster than others.

But somehow EV horsepower is different, my Tesla motor is only 150KW, or 201 HP (it’s the slow Tesla) yet it accelerates it’s over 3,600 lbs of mass to 60MPH in 5.3 sec

Some will say it’s due to torque, but as the hp formula is torque x RPM / 5252 it shouldn’t matter, but I know of no 200 hp 3600 lb ICE car that will accelerate that hard.

While I agree the useful electric airplanes aren’t close yet, electric will eventually replace ICE, whether you like it or not, everything except he batteries is already there

A few years ago I thought EV’s would go to stations and their battery pack would be swapped out by automation, sort of like renting propane tanks, I didn’t think batteries could be charged fast enough to work, but having driven a Tesla on a trip a few times and recharging to over 80% in 15 min or so, I see it can.

A better question I think is what kind of cycle life does this pack have, and what does a new one cost, what’s the warranty etc? Cause if they are using almost all of the capacity, it probably won’t last longer than a phone battery in cycles, and if you plan on cycling it say 5 times s day, then it may only last 1/5 as long as a phone battery or less.

Your tesla is quick for the same reason my 255hp 5 series Diesel is as quick to 60 as the 300HP gas version.  It makes more torque over it's entire rev range (which is 2000rpm narrower)  We look at peak HP in cars but it does not tell the whole story. At 1500rpm the diesel is making 413lb/ft and the gas car has hit it's max of 295lb/ft.  I have to grab the next gear at 5K while the gas car spins all the way up to 7K which is why it makes higher peak power.  So it can do more work over a period of time at max power, but when we have to use multiple gears and a wide spectrum of the rev range, that max power advantage can be matched or over come by higher mean torque across the rev range.  Teslas and other EVs have that benefit in the extreme with no tuning compromises...Peak torque now and through the whole rev range.  This does not really come into effect with aircraft because they operate at a constant and very narrow RPM range.  The benefit with regard to a trainer is they only really need significant power in the take off and climb.  Very little power needed to hold speed on downwind and if you managed energy well even less from abeam the numbers to touchdown.

Edited May 2, 2022 by Shadrach

[A64Pilot]

However a CVT allows an ICE to reach and hold peak power as the xmsn varies ratios.

I would have thought they would have found their way into performance cars but they never did, I think it’s because people like to feel the power build, the change in engine sounds etc.

A CVT feels like a slipping clutch to me.

A prop is a form of CVT in an airplane and a boat

Edited May 2, 2022 by A64Pilot

[Shadrach]

6 hours ago, A64Pilot said:

However a CVT allows an ICE to reach and hold peak power as the xmsn varies ratios.

I would have thought they would have found their way into performance cars but they never did, I think it’s because people like to feel the power build, the change in engine sounds etc.

A CVT feels like a slipping clutch to me.

A prop is a form of CVT in an airplane and a boat

CVTs seem great on paper. The ones that I have driven were awful to drive and posted lousy performance numbers compared to conventional transmissions.  Very much like driving an under powered motor boat on land...

Edited May 3, 2022 by Shadrach

[AH-1 Cobra Pilot]

1 hour ago, Shadrach said:

In addition to math, reading is a challenge as well....This plane has been flying in Europe for over 5 years. It was designed from the outset for pattern work and has proven itself able to replicate the mission many of us accepted in our early training.  It is designed to climb to pattern altitude at >1000FPM, throttle back to low power settings for downwind, base and approach. At 27KW airspeed is >80kts.  

It's been more than 20 years but I have fond memories of doing "circuits and bumps" in the Indiana summer while honing my skills in a 1966 C150F.  This thing has about 3X the climb of a C150 in August.  Perhaps new pilots will learn to be more judicious with energy management with a battery meter to monitor.

This reads like you guys are mischaracterizing this machine so that you can $hit all over EVs.  As it stands currently it's a viable training aircraft and I am sure endurance will improve.

 

Listening might also be a challenge.  "17 minutes, 65% remaining."  None of the numbers add up, and there are BIG differences between the article and the video.  Plus, "10 minutes reserve required if you stay in the pattern."?  Is that rule coming to America?  I suppose other rules may be changed as well.  Can you log time if the propeller is not turning?  It will make sense to change some rules; what is infuriating is how easily some are/will be changed when it it so difficult to change others for the not-so-politically-popular innovations, i.e. electronic mags.

It is not the 'I have something against EVs', it is this type of hype that is so ridiculous, and will be harmful to some suckers.  As I have said before in other threads, electric airplanes are probably 40 years out, and anyone investing will not see a recoup for decades, or until the Zero Point Module is invented...

[Fly Boomer]

6 hours ago, A64Pilot said:

hp formula is torque x RPM / 5252

Electric motor generates 100% torque at zero RPM so, apparently, zero HP at zero RPM.

[carusoam]

47 minutes ago, Fly Boomer said:

Electric motor generates 100% torque at zero RPM so, apparently, zero HP at zero RPM.

Fortunately, the marketing guys like HP ratings… 

The tech guys dig torque…

ICE engines (Chevy 350s) give a pretty flat torque curve for about 1500rpm… advise shifting at the high end, to come back in the low end, one gear higher…

Two shifts, you are going through the timing lights, a 1/4 mile away… in third, at 100mph… Firebird, box stock… nothing fancy… 300hp, 400ft-LBs..

Fuzzy memories only…

 

The electric motors are fantastic!

Unfortunately,

their fuel system is outrageously heavy… 

The fuel tank is incredibly small…

Tough for both sports cars, and planes….

Corvette guys won’t care so much…. Their sports cars are a bit heavy compared to the Lotus crowd…

 

The added big problem with electric motors in planes vs. cars….

Cars like to use the regeneration… around town… Vs. Highway.

Planes barely ever hit the brakes… so we are going to miss the opportunity for regeneration… fortunately… 

 

PP thoughts only, I’ve only seen rumors about an electric Corvette…

Best regards,

-a-

[PT20J]

1 hour ago, Fly Boomer said:

Electric motor generates 100% torque at zero RPM so, apparently, zero HP at zero RPM.

That is true. Power (horse or otherwise) is the rate of doing work, and work requires applying a force over a distance. No movement, no work, and no power. It's just a definition.

[mike_elliott]

7 hours ago, carusoam said:

Their sports cars are a bit heavy compared to the Lotus crowd

Lotus Super 7, IMO the only real sports car, right @DonMuncy?

[A64Pilot]

9 hours ago, Fly Boomer said:

Electric motor generates 100% torque at zero RPM so, apparently, zero HP at zero RPM.

That would be correct, because at zero RPM no work is done, so no horsepower

Never mind I saw that had already been answered

Edited May 3, 2022 by A64Pilot

[A64Pilot]

Regen in an airplane would be very useful, not for battery charging but to slow down and steep descent, short field etc, plus reverse thrust ought to be dead easy for an electric motor, and no need for a constant speed prop. An electric airplane ought to be very inexpensive to own, no mags, oil changes, no plugs, prop governors, exhaust, no decrease in power with altitude or hot days.

Just need that magic battery

Regen in cars is inefficient, more efficient to coast, but regen works when people use their brakes, it does recover some energy, but it’s best use in my opinion is no brake wear. Average person continues to accelerate to a red light and lifts the accelerator and immediately starts braking, makes as much sense as continuing to climb until it’s time to descend, but most do it.

By the way to charge that 20KWH battery at my home rate of 14c per KWH would cost $2.80. Add in efficiency losses in fast charging (heat) maybe $3.50?

Fuel cost of $3.50 an hour or less ain’t bad

Edited May 3, 2022 by A64Pilot

[cbarry]

It would be an awesome day when an EV is responsibly feasible for the entire life of the vehicle.  This  is not intended to disparage anyone who has chosen to go EV, but the  true production costs, carrying costs and disposal costs to sustain an EV network, at this point, are being absorbed by investors, tax payer funded federal subsidies and fairy dust accounting to make it seem appealing to the masses.  For example, the “zero emissions” standard most see as an attractive feature as to why consider an EV mostly ignores the energy used to serve the EV is typically not zero emissions (renewables are just not yet a significant portion of the energy grid).  Thus, coal and natural gas are the primary sources for the energy used to produce, charge and dispose of the EV fleet.  An EV aircraft enters the same circle of life as an EV ground vehicle and has the same issues—at this point.  Maybe when I see our Air Force being converted to EVs, I’ll be a buyer!

[Kmac]

I think the thread title alone would draw in more of an anti-ev/anti-ea crowd.  

I agree with @Shadrachthat the aircraft referenced seems to accomplish the circuit mission well.

[A64Pilot]

Same exact arguments were used and debunked for hybrids

I don’t understand and never have why so many are against new technology? Did you guys ever buy a microwave, or are you still certain they cause cancer?

Who cares how it’s fueled, if it costs far far less to do so, requires less maintenance, is at least as reliable, and lasts at least as long as an ICE car?

The cost to fuel an efficient EV compared to ICE is the deal killer for me, the smooth silent performance etc are just gravy. I don’t care if it runs on ground up baby seals or whales, I don’t think most EV early adopters are the Green peace activists you think they are, From what I’ve seen they are older CB’s who want to reduce their fuel and ownership costs, not their carbon footprint. But if it does, sure why not, more gravy. It cost $7 to fuel our EV for 250 miles

How can anyone seriously think an EV that travels over 250 miles on 50KW of electricity doesn’t pollute less than an ICE vehicle that burns 10 gallons of gasoline or Diesel to do the same? Grid power has always been a huge success story, it’s very clean as being so huge and stationary etc they can be very efficient and clean, and transmission losses are a fraction of what I thought they were. We only lose about 2% in transmission and 4% in distribution.

Now if you run an old Diesel gen set to charge your EV, we’ll then that may not make much sense, but grid power sure does.

Solar should but I’m not sold on the payback interval, I think by the time you add in the cost of money to the payback time, it’s not really viable economically. To bad because one side of my hangar roof faces South and if I removed three trees would have no shading.

 

Edited May 3, 2022 by A64Pilot

[A64Pilot]

For those that really want to know, try this webpage, the screen shot is our car vs a new ICE car for where we live, change the zip code and you will get results for where you live, source of power is of course the difference, maybe you have a coal plant?

https://www.fueleconomy.gov/feg/Find.do?year=2021&vehicleId=43821&zipCode=32195&action=bt3

screen shot won’t upload?

This covers the life cycle emissions of a EV / vs ICE

https://www.epa.gov/greenvehicles/electric-vehicle-myths#Myth5

Edited May 3, 2022 by A64Pilot

[Fly Boomer]

1 hour ago, cbarry said:

the  true production costs, carrying costs and disposal costs to sustain an EV network, at this point, are being absorbed by investors, tax payer funded federal subsidies and fairy dust accounting to make it seem appealing to the masses

FACT:  Electric vehicles typically have a smaller carbon footprint than gasoline cars, even when accounting for the electricity used for charging.

I know this comes from the gubmint, but it might be right:
https://www.epa.gov/greenvehicles/electric-vehicle-myths

This graph shows lower overall greenhouse gasses including both manufacturing and end of life:

Oops, I see that @A64Pilot beat me to it.

 

[exM20K]

1 hour ago, A64Pilot said:

How can anyone seriously think an EV that travels over 250 miles on 50KW of electricity doesn’t pollute less than an ICE vehicle that burns 10 gallons of gasoline or Diesel to do the same?

Define pollution.  

• The majority of automobile pollution is tire “dust.”  EV’s are typically heavier than comparable ICE autos, and tire wear is a function of vehicle weight. Maybe an EV has marginally less break pad wear, but it’s not even a rounding error.
• The petroleum exploration production, refining, and distribution system is mature, safe, regulated, and clean.  The same cannot be said of the metals-for-batteries producers.
• 276 million cars in the US.  If batteries are discarded every 10 years, how and where will 27.6 million batteries  be disposed of safely every year?

I am not hating on EV’s.  But the pollution, efficiency, and economic impacts of a mass changeover are not as simple as $ per mile or fuel-at-the-end of the production cycle pollution per mile

-dan

Edited May 3, 2022 by exM20K

[Fly Boomer]

2 minutes ago, exM20K said:

batteries are discarded every 10 years

Why would you discard a perfectly good battery after only 10 years?

[201er]

1 hour ago, A64Pilot said:

Same exact arguments were used and debunked for hybrids

I don’t understand and never have why so many are against new technology? Did you guys ever buy a microwave, or are you still certain they cause cancer?

These things seem like a good idea on paper.

 

But, sometimes it's better to wait till they work out all the kinks.

 

 

 

[exM20K]

8 minutes ago, Fly Boomer said:

Why would you discard a perfectly good battery after only 10 years?

Cars are scrapped about every 15 years, and thing break. Technology improves and obsoletes old tech.  Maybe the right number is 20 years.  Who knows? It’s not zero. Do you disagree that pollution is broader than emissions per mile or just being pedantic?

-dan

[Fly Boomer]

2 minutes ago, exM20K said:

Do you disagree that pollution is broader than emissions per mile or just being pedantic?

I don't disagree that pollution is broader than emissions per mile.  But you are implying or hoping I'll infer that overall pollution is worse for vehicles with big batteries.  Many people who are smarter than me seem to think that overall pollution for vehicles with big batteries is less.  I read those things, I consider their credentials and, if it passes the credibility test, then I agree with them.  See discussion above.

[MIm20c]

I was thinking we needed another Tesla thread…

Ironically I just picked up a Car and Driver magazine to read about the GT4. Inside there was a long term review of the Model 3, less than 2 years and 40k miles. The cost at the “pumps” was $3413 using a super charger 43% of the time (8.5c per mile).  At 5k miles towed to the dealer to replace rear motor. Battery lost 6% of its capacity in the first year but remained the same on the second.  Tesla warranty on the battery is 70% after 8 years, curious what a 15 yo battery will hold 60-70% of delivered range…?