Rare earth elements are used to produce magnets with very high strength that also strongly resist demagnetization, their performance is key to modern motors such as those in electric vehicles (EVs). The stronger the magnets, the lighter and more efficient a motor can be. So what exactly does it take to break up with rare earths?
Rare earth elements (REEs) are actually abundant in the Earth’s crust, technically speaking. The problem is they are found in very low concentrations, and inconveniently mixed with other elements when found. Huge amounts of ore are required to extract useful quantities, which requires substantial industrial processing. The processes involved are ecologically harmful and result in large amounts of toxic waste.
Moving away from rare earth magnets in EV motors would bring a lot of benefits, but poses challenges. There are two basic approaches: optimize a motor for non-rare-earth magnets (such as iron nitrides), or do away with permanent magnets entirely in favor of electromagnets (pictured above). There are significant engineering challenges to both approaches, and it’s difficult to say which will be best in the end. But research and prototypes are making it increasingly clear that effective REE-free motors are perfectly feasible. Breaking up with REEs and their toxic heritage would be much easier when their main benefit — technological performance — gets taken off the table as a unique advantage.
In my humble opinion there is really no need for the extreme performance that currently is one of the common selling point for Electric cars 😀
There is no need for Teslas to have insane acceleration, but unfortunately, that’s not the type of performance here.
Performance is energy efficiency. It’s no good if you make a motor that has no rare earth metals, but using it depletes your batteries faster, which also require ecologically damaging processes to produce.
The good news is, without the perverse incentives created by the petrodollar, maybe the youngest of us will see fusion power and room-temperature superconductors become reality… then, energy can be stored or converted to work essentially without loss, but I’m not holding my breath. (n.b. NOT free energy, you still need energy to do work, but the losses would go away)
“The good news is, without the perverse incentives created by the petrodollar…”
Without the “perverse incentives” of arbitrary regulation and taxpayer-funded subsidies, commercially available EVs wouldn’t even exist.
BTW, in Q4 2022, Tesla made $1.78 billion selling “carbon credits.” You can’t eat a carbon credit, you can’t hold a carbon credit in your hand, and you can’t drive one. A carbon credit doesn’t even reduce pollution. But it does give governments more control over your private life and it further consolidates wealth among the super-rich.
We had both EV’s and many kinds of combustion vehicles back when horses were an option up for comparison, all of which were terribly poor performing and not nearly as common compared to modern cars of course. Then petroleum burning ICE’s took over because when you don’t care much about what happens to the stuff you burn, and you can arrange things so that your society can run on a steady supply of petroleum, it can be easy and rewarding for multiple generations.
We actually had a number of biofuels and means of fuel production predating the petroleum boom that died out because they couldn’t compete with the “perverse incentive” we created by not charging anyone for the eventual cost of even just the CO2 portion of what they littered the atmosphere with. Restricting the burning of things once it’s been done enough that harmful effects become apparent is something we’ve done since long before the industrial revolution. (Think of the burning of smelly, smoky fuels in stoves in historic cities such as London.)
That said, it’s hard to argue that the nations who had a fossil fuel powered industrial economic boom would have done so well without it, nor would we have developed science and tech so quickly, but neither is it fair to say that this was ever a situation that was naturally stable – fossil fuel use was always artificially propped up, and we’re struggling to keep that up.
Don’t forget that burning oil was once seen as an improvement over the alternatives. The discovery of fossil fuels actually solved the first energy crisis of the beginning industrial revolution, when people were chopping down all the forests to make fuel for making iron and steel. The “alternative fuels” were unsustainable against the growing demand.
Well, yeah, we are great at overusing things and then we found a brand new thing to overuse- we have long since been driving species to extinction, destroying thousands-of-year-old ways of life, and farming in ways that spoil the land. Industrial nitrogen fixation is relevant too, speaking of farming. But anyway, I’m not saying petroleum is the only time we ever did something unsustainable. You could point fingers between the use of coal in Britain and having run low on wood, for instance. And besides, at lower tech levels where you’re just trying to make iron and steel, it’s harder to avoid using coal if you have it. Back then we didn’t have as much pinned down about the situation anyhow, although it still frustrates me how we keep on forcing the next generation to share smaller and smaller slices of the pie anytime there’s a choice.
The thing I was trying to highlight is we didn’t really veer this hard into petroleum until late enough that we did have some promising options in other directions, and we knew that it wouldn’t last forever, but now we’re pretending otherwise. They may or may not be promising now, but at the time they would have been promising enough. ABE fermentation, perhaps, or various things turned into simple fuels like ethanol- maybe less like the USA’s corn and more like Brazil’s sugar cane. A number of things that don’t even have to use purely renewable biomass wouldn’t make for as much impact if we had aimed for outputting a lot of the carbon as a solid when using them for energy input. Pyrolysis of various things can be applicable at a range of tech levels, even though it’s not as easy or productive as water-gas-shift or our regular usages. While it may not have been truly practical to avoid what we did without ruining a nation’s industrial economy compared to the economy of the ones who didn’t mind borrowing against the future, it’s not that the other ways to get energy into the system are unnatural, ineffective, impractical, etc. It’s just easier/faster to borrow a thousand bucks than it is to make a thousand bucks profit, if you ignore the need to pay the shark back at the end.
Things like a cheap led flashlight with a rechargeable battery and a small solar panel could be compared to a whale oil lamp. There’s no longer any real need for the latter, we probably agree. What about the best lanterns I ever used? They ran on propane, the same cheap fuel that would also power a camp stove and never spoiled. They had gas mantles that made white light at much higher efficiency than any bare flame, and the brightness could be varied considerably within a range, and they were very well behaved as far as flame stability in wind, or the production of smoke and fumes. And yet, nowadays unless I was poorly prepared for the modern way and still had a lot left over from the old way, I really wouldn’t see a need to use them instead of a flashlight either. In my mind, that’s not the last thing that’s going to change, and we ought to view some of the things we grew up doing as a temporary thing rather than the way things always were and will be.
>we are great at overusing things
People, even at the point of starvation, rarely fail to make more people.
>until late enough that we did have some promising options in other directions
Like what? Diesel designed to run his engines on peanut oil. Ford assumed farmers would run their tractors on ethanol. None of that was scalable to 8 billion people.
Brazil’s ethanol works pretty well. My country doesn’t lean into farming as much as them, but we used to be mostly farmers and didn’t use nearly as much mechanized energy back then. And to my knowledge, in the U.S. ethanol has waxed and waned according to the current price of oil and whether ethanol was prohibited or taxed at the time. So if gasoline had always included the externalized costs and everyone wasn’t competing so heavily, I imagine ethanol could have taken up some slack. Maybe we’d not have needed leaded gas as much, with the octane boosted by ethanol. And, well, it wasn’t just during prohibition that selling distilled spirits was a decent source of money for farmers – historically, you could bring the surplus from your harvest to market much easier as a long-lasting liquid than crops on a cart. It’s something we at one time were very attached to, whatever the numbers, so maybe that’d have helped for motivation.
Actually though, even apart from actual replacement attempts like wood gas, fermentation-based fuels other than ethanol, external combustion of relatively raw biomasses, etc, it would even have been slightly better if we had done even easy stuff earlier. Even stone age people can store carbon for a very long time just by making earthen mounds or charcoal pits in excess of how much charcoal they actually end up burning. Of course, you need few enough people to not run out of trees in that particular case, if you’re relying just on a forest you’re managing. And for other circumstances and goals, you don’t need to go all the way to hard charcoal, just keep stuff from rotting too much.
If we weren’t competing, and just planning ahead, we could have at some point figured that we’ll have access to more fossil fuels than we can afford to actually burn, and focus on trying to get results per co2 output. That could tend to make it make more sense to burn lighter alkanes when you can and to try charring/pyrolyzing other things rather than burn all their carbon. Not as cheap as getting the most energy out of the fuel you bought when there’s no incentive to care about the carbon. But at least the price of that option is not decoupled from the price of the plain fuel, and it seems possible to incentivize by non-insane levels of messing about with taxes and things.
That all said, we could also have ended up using some of the difference in price to pay for e.g. boosting the rate of storage of carbon in weathering rocks or the deep ocean or whatever. If that somehow worked, I guess I’d be happy with that option too. Mind you, again, depending on the time period we’re talking about there were times that it wouldn’t be reasonable to expect everyone to be on the same page about things. Earlier than you think, maybe, but still. Like I was saying, it’s not “easy” but there’s things that could have helped at various steps and things that there’s no shame in picking back up where we left off. Just because we had reasons for what we did doesn’t mean that they set a new normal forever. But hey, not going to solve the world’s problems in a series of long comments on an article about motors.
What do plants breathe, and at which concentration do they starve?
Oil producer subsidies were installed to make more oil faster and cheaper, and to support domestic producers instead of imports, which was a return on the money.
EV subsidies are used to prop up a technology that isn’t quite ready – the market would be much smaller without the subsidies. The rationale for such consumer side subsidies is the same as above – get it done faster – but the market doesn’t end up working that way because the subsidies are used up by companies that simply sell immature technology to turn a profit, not to advance the technology. The companies that use the subsidies to advance the fundamental technology end up growing slower than the ones that simply sell more of the same old stuff, so the market is taken over by those companies that simply hoover up the loose money into their owners’ pockets.
In other words, if EV subsidies were properly placed, they would be given to Panasonic, LG, etc. instead of Tesla – put the money where it counts.
Government subsidies are legal theft… I don’t care who/what they’re for. Carbon credits have nothing to do with “saving the earth,” they are the modern equivalent of selling indulgences, and nothing but a money-making scam.
There is a shortage of lithium, with no new significant sources identified. Even if there was, typically, the same people who want to mandate electrics on everyone, also don’t want any mining activity in their own back yards. That’s pretty much the case for rare-earth minerals and, worst of all, for copper, without which you can’t wind motors or wire up a delivery infrastructure.
Then there’s the electric grid, which has about 1/10 the capacity needed to power a nation-wide fleet of electrics, not to mention the fact that the grid is engineered for load-leveled delivery, not supplying the kinds of impulse loads that high-performance car chargers represent.
I gather you’ve never had a basic economics course… where they talk about supply and demand and the effect that has on a commodity’s price. Given the present state of things, your electric wet dream will actually manifest as a nightmare of nation-wide rolling blackouts and winters where elderly people will freeze to death because the won’t be able to afford the electricity to heat their homes anymore.
Electric drive trains are capable of incredible road performance. I like the idea of electric cars… particularly the fuel-cell variety. But ramming the present state of the art down the throats of an unwilling public is not visionary, it’s just stupid.
As to your closing remark… it says a lot more about you than it does about me.
“Oil subsidies make EV subsidies look like chump change.”
I’d like to see numbers on that, evaluated as (dollars)/(vehicle_life). Total oil subsidies versus total EV subsidies is an invalid comparison. Also, many call the oil depletion allowance a subsidy, which is also invalid.
Chris Maple:
I’ve seen hippies claim that gasoline tax is a subsidy on IC vehicles.
They’re not smart people.
You got it wrong. Your number is for 2023 and covers the entire year. The 2023 Tesla revenue was $96.773B, so the carbon credit contribution was 1.84%.
Hey, remember that the lion’s share of research into nuclear energy of every kind was done by the people with the petrodollars. You can’t just blame perverse incentive structures, those are holy grails of technology and very very difficult to develop
>Performance is energy efficiency.
Not really. There’s no fundamental efficiency penalty for ditching the permanent magnets, but there are engineering tradeoffs.
Today’s electric cars use a single reduction gear to save the cost and complexity of a gearbox. Without permanent magnets, you’d have to spend tremendous amounts of current to magnetize the motor at low RPM, to achieve the same performance off the line.
Add a gearbox and the problem goes away, but then you have to shift gears, and with the high reduction ratios needed, it’s difficult to make a gearbox that doesn’t break constantly when the motor is back-driven by the wheels.
Isn’t that where CVTs come in? No need for ‘gears’….
Your suggestion is to put a _terrible_, unneeded transmission into electric cars?
It solves the problem of having to change gears, but does the opposite for all the other points, including limited torque and not being able to back-drive the motor so no regenerative braking.
> There’s no fundamental efficiency penalty for ditching the permanent magnets, but there are engineering tradeoffs.
Exactly
> Today’s electric cars use a single reduction gear to save the cost and complexity of a gearbox.
True. I don’t really know why they don’t put an overdrive unit (planetary 2 speed) in. My car, with its PM motors still has inadequate stall torque – it can’t get up a very steep hill. It is 4wd, but cannot even break it’s tyres out of the ice at the skifield the stall torque is so low.
> Without permanent magnets, you’d have to spend tremendous amounts of current to magnetize the motor at low RPM, to achieve the same performance off the line.
This simply isn’t true at all. What you are thinking about are Type A squirrel cage induction motors, being operated from a fixed frequency, fixed voltage mains supply.
It simply is not true of an invertor driven motor, with a suitable rotor design (not type A)
You can make a type C rotor, or just use a wound rotor slip ring motor. Though if you do that you can just push DC though the rotor. There are (as you say) engineering tradeoffs, but none of this stuff is new. It’s not even old, most of it is more than a century old, there simply was not the pressing need, nor was there a cheap, efficient way to electronically commutate motors.
Transformer coupled wound rotor motors (i.e no slip rings) are not new either, but the extra size reduces enormously when you can run the exciting transformer at high frequencies.
>Add a gearbox and the problem goes away, but then you have to shift gears, and with the high reduction ratios needed,
(Petrol) cars don’t run the gear box at high ratio** – that is done separately eg at the diff. Gearboxes tend to be ratios +/-1, as this mechanically keeps the size down, or is just an inherent property (eg 3 speed planetary units) (**except 1st)
>it’s difficult to make a gearbox that doesn’t break constantly when the motor is back-driven by the wheels.
Every manual car made since for ever did this, so really not true.
So actually I agree with you, only moreso!
>This simply isn’t true at all. What you are thinking about are Type A squirrel cage induction motors
In all electromagnetically excited motors, you waste power by driving the field coil to generate torque, and that shows up as poor efficiency at low RPMs. Permanent magnets give you the magnetic field for free, making them superior for one-gear operation – basically any time you’re driving at city speed limits.
>(Petrol) cars don’t run the gear box at high ratio
But electric motors do, given that you get smaller motors with greater power density by running them at far greater speeds than ICEs.
>Every manual car made since for ever did this, so really not true.
The original Tesla Roadster was supposed to have a two gear box, but since the motor turned up to something like 20,000 RPM they had troubles making the gearbox last in the low gear and ditched the whole idea.
More to the point, if you don’t use permanent magnets, you want to design the motor to run at very high revs to generate power through speed rather than torque, because that mitigates the problem of having to spend as much amps in the field coil – but then you get the gearbox problems.
“There’s no fundamental efficiency penalty for ditching the permanent magnets, but there are engineering tradeoffs.”
Permanent magnets create a magnetic field without a continuous input of electric power. Electromagnets require continuous electric power input, and will continue to do so as long as we don’t have high temperature superconductors. Continuous power drain is inefficiency. Furthermore, I suspect that a PM motor weighs less than equivalent alternatives, and higher weight means lower efficiency.
Well, then we should use permanent magnets on BOTH sides! Oh wait, wrong article. https://hackaday.com/2024/07/01/a-brief-history-of-perpetual-motion/
:D :P
There is always going to be at least one nonzero resistance winding if we’re not using superconductors, and while permanent magnets are *nice* it’s still true that the loss when a single winding operates against magnets can be higher than when two windings operate against each other. Even the losses in one big one or two little ones aren’t always going to fall one way or the other, or if so it’s not obvious to me. Or to put it another way, it’s not true that all motors that use magnets are more efficient than all motors that don’t, and it seems as if it would have to be true if the simple theory was perfect.
The efficiency penalty of electrically excited motors can be overcome by designing the motor to turn faster, to the point that the difference is negligible – but then you get other mechanical issues like stripping teeth at your reduction gear when you try to back-drive the motor suddenly.
“Performance” here means efficiency. And yes, it is absolutely necessary. I mean, why consume “x” when you can consume “0.9x”?
Just use a smaller motor and cap the acceleration to match the efficiency curve. Never believe a tech nerd when they tell you something is “absolutely necessary”.
Because you don’t want to destroy the land mass of a small country for a few cars that are going to last 20-30 years before they’re obsolete?
The weird bit about electric cars is that they don’t really use all that much more energy per extra horsepower.
Our car, not a Tesla, has a two-motor variant with 2x the horsepower that only gets something like 5% worse mileage. (Assuming the same driving behavior — if you’re always lead-footing it, of course, more watts are required.)
It’s shocking how steep the curve is, and you can hardly blame folks who want a zippy ride from going for that alternative. And you can hardly blame the manufacturers from playing to the electric’s strengths either, IMO.
Just wait until motor-per-wheel becomes the norm.
The world really needs heavier cars that accelerate faster for operators with poor spacial skills, poor reasoning capabilities, and poor reaction times aka the typical car driver. These cars don’t stop any faster the heavier they get.
Clearly the original Hummer was too light and too slow. Truly a menace to society.
That’s why we need 9000 pound trucks accelerating 0-60 in 3 seconds! That’ll make everyone safer!
Think of the children (and how efficiently it can mow through them)!
Hummer EV is an Emotional Support Vehicle.
To some extent EV do stop quicker, the weight of them is a disadvantage, as there is more energy to shed. However the COM being so very very low means all 4 wheels have good traction under heavy braking and with more weight comes more traction anyway. So when you assume skill or good ABS in both the stopping distance of an EV is often a tiny bit better despite the weight.
I do agree though high performance vehicles that can so easily harm others really should require an ‘advanced driver’ course and license that can easily be revoked – its much easier to do something stupid when getting to a speed higher than you should go under the conditions in this location takes virtually no time… Here at least we already have a sort of similar framework with motorbike having multiple license levels. So to be allowed onto the powerful machines needing more certification, yet for 4 wheels the only restriction is on towing weight and HGV type stuff, performance doesn’t matter at all. Which to me seems very odd – lets be so careful to protect the rookie motorcyclist from themselves more than anything, but not care about the damage a rookie driver in the huge power and weight car can do to others..
Hell yah! Survival of the fittest! Just imagine the driving that our great^8 grandchildren will be capable of! Meanwhile… a population drop would buy us time to work on climate issues.
Actually, torque is an issue with EVs and tire life. I understand there are now special tires designed just for EV usage, but without carefully feather-footed acceleration, the high torque from EVs’ motors means a set of nominally 40k-mile life ICE tires will only last you 10k miles or so on an EV.
(Is anyone here familiar with purpose-made EV tires? What kind of mileage do they get, and what’s the cost differential vs garden-variety ones?)
That is a huge issue that ‘could’ be adjusted to improve with software work though…
Everyone talks about torque like the only important thing is the high score, but coming from drag racing there is always a break away point where more torque does nothing but literally burn tires… For a daily driver that is just pointless.
For consumer EVs, especially in 2wd vehicles, I never hear about traction control or optimizations to offset the unusably high torque of electric vehicles.
A less obnoxious form of traction control should be standard to limit torque to your traction curve so you don’t need to actively think about it.
With ABS and wheel speed sensors standard now all of the data should already exist in the car…
There’s always going to be some knuckleheads that just want to show off their ability to eat a tire. As nice as not obliging them may be, if it means they won’t let go of oil even with their cold dead fingers there could always be a feature where when the pedal hits the floor the traction control turns off.
Again, just a piece of cake for software.
I think you may be searching using the wrong keywords, “throttle response” might do it. Having driven an old Leaf, a Polestar 2 FWD and a BYD Dolphin I can say the Leaf didn’t feel like it limited torque at low speeds while the P2 and Dolphin did. You can tell the speed at which the Dolphin stops limiting torque as it wheelspins at 20+ mph not 0.
I’ve never driven a Tesla but they’ve got a reputation for sharp throttle response and high torque from 0 but that’s not the only way to do things.
It’s not just the torque, it’s also that most car gains between 500-1000kg in electric versions… even assuming the same torque applied when you accelerate, just having that roll is gonna use your tires quicker…
@elwing, less than that usually. E.g. an entire Nissan Leaf 62kwh battery pack is about 400kg. What’s an ICE weigh, 100kg?
Combined with bigger cars generally though it doesn’t help, people trading in their 1000kg hatchback for a 2500kg range rover.
> What’s an ICE weigh, 100kg?
The EV has other stuff besides just the motor. The motor controller, battery controller, gearbox, and the extra motors for pumps to drive the brakes, coolant, power steering, AC, etc. and the heavy gauge wiring add up just as much mass as an ICE with belt driven everything. The “engine” of an EV is roughly equal in weight of the ICE all told.
Well the trick there is to not be cosplaying as Clarkson on a track when he isn’t paying for the fuel or tyres…. You don’t actually need to to put all that force into smoking your tyre, but it can be nice to have the power available when you do want it.
(though if the pedals are too sensitive etc some remapping makes sense)
If your car cannot break the tires loose at any speed, in any gear you have a power problem.
If it can, you have a traction problem.
Work on it.
I recall reading that EVs are significantly more polluting than comparable gas cars in terms of fine particulates, which are produced by wear on the tires and on road surfaces. I would guess that the issue is closely related.
If some light regulation could avoid a 400% increase in the number of aerosolized tires we’re breathing in, AND save EV drivers money, this is probably the ideal time to do it. Once everyone owns a car that can accelerate hard enough to crush a watermelon, it will be much harder for politicians to take that away from them.
Having checked, that claim about EV particulate emissions is contested (and there are paid lobbyists on both sides of the question). But it does sound like there’s a case to answer:
https://www.sciencedirect.com/science/article/pii/S004896972204058X
Anyway, to whatever extent EVs really are getting through tires quicker, that rubber is all going into the air.
True if you speak directly about percentage efficiency in a motor-focused way. As an aside, I would like motor-per-wheel for the traction / force balance / etc reasons even without a high total power output.
I think designing to support high outputs should have packaging implications that could limit the designs you can pull off. Hypothetically, if you could fit modest motors practically into each wheel well (if not just hub motors, unsprung weight be damned) then you don’t need a diff in the middle with half shafts across the full width. (Which should be a slightly less efficient type of gear, as compared to just a reduction gear, but mainly it’s just an extra part that is convenient to do away with.) Without that, your undercarriage can be smoother, and you now have an easier time laying batteries all down the middle, so maybe it keeps you from having to put them under people’s feet. Maybe that lets you reduce the height between the belly and the roof, meaning you get higher efficiency by aero. To be fair, maybe that’s not a problem we’re running into with current car sizes versus battery sizes. Either way, actually installing high output should directly represent a bit of weight and cost and such that’s outside of the actual motor losses.
Maybe horsepower per ton could be a decent metric, even though drag and powerbands are left out by that number. ~125hp per ton has actually been more than sufficient for me even in an ICE pickup, which I’m using as an example of something of similar weight with worse drag and worse power band. I would assume an electric sedan with a good powerband and no shifting wouldn’t need that much power. Yet the performance option for some of the tesla’s can go up to 400hp/ton for a fairly low aero drag 2.5 ton car, and if you want their largest battery for range reasons, you’ll probably be forced to take at least… 200 to 330 hp/ton? I guess to be fair, if I look at a different brand such as Hyundai instead, I see more reasonable looking numbers – their ioniq 5 says the largest battery can be had with between (approx) 90 and 130 hp/ton depending if you get the AWD or not, and the Ioniq 6 looks similar.
If something has even just double the power that it needs, that’s a higher rating for not only the motors and mechanicals, but also wiring, drive circuitry, cooling, etc. I assume those items will probably cost and weigh less than exactly twice as much, but surely it won’t be insignificant all totaled?
That’s your prerogative, but I think that shedding the frumpy and gutless image of electric motors did help to finally un-kill the electric car. It was part of a strategy. Like it or not it helps to be dangerous and sexy when you are marketing stuff
Nah, that was just Tesla’s PR talk. Electric motors per se had higher performance all the way back to 100 years ago, when the first speed records were set with electric motors. The limiting technology was the batteries all along – the power density of lead-acid and Ni-MH were abysmal unless tortured to death.
The practical performance of EVs outside of specially built vehicles didn’t pick up until Lithium batteries came along. It was Nissan who first put Sony’s then new Li-Ion cells in a prototype vehicle in 1996 and showed it was feasible to make an EV that matches the performance of an ordinary car in the real world. The issue then was cost, because the tech was brand new, and specific energy density, since the batteries still weighed almost double compared to lithium batteries that came along 10 years later when Tesla started building the Roadster. Tesla really didn’t push the technology along as much as they claim – it was Panasonic who made better and better batteries that made Tesla possible.
Point being “It was a strategy” is just retconning what really happened – unless by “strategy” you mean waiting until the technology matures and then claiming credit for it.
It’s _much_ more fun to drive a slow car fast then to drive a fast car slow.
That said, Tesla is doing 100 dumb, status symbol, things. (e.g. Idiotic door handles)
Not really that dumb from an MBA POV, because expensive cars ARE just status symbols. No Ferrari street car drivers can drive.
If Tesla is going to stop competing with Benz and start competing with Honda, they will have to change.
They can ship unrepairable money pits and still look good compared to the Germans, but there are only so many pretentious (richers/loan fools).
It seems to me, based on decades of observation, that the general lifestyle of the US citizen (and, likely, of those comprising other “developed countries”, but I have only traveled, not lived elsewhere) is fundamentally guided by the continual abandonment and replacement of nearly everything, based upon “status”. I do not believe I am aware of any significant fraction of those I encounter that efficiently utilize any item until it’s replacement is justified by the simple notion that doing so will not incur significant waste. The drive (pun intended) to navigate our life punctuated by consumption and possession-related milestones, motivated by shallow, external, emotional imperatives, is such ubiquitous behavior that it is considered essential. Overcoming the collateral damage of this philosophy is sort of like needing more and higher paying employment to solve a gambling problem, where the more is earned, the more is lost; a degenerative system. It is interesting that nearly every “basic” item, including a vehicle, is reviewed based not mostly upon what it accomplishes regarding an intended “basic” priority but rather how such a “basic” item may only be suited to those “who are not car people”, for example. Implication: Those unenlightened folks who don’t appreciate how much others will admire my idiotic door handles, or other wasteful silly features. I have a workmate who avoids letting me drive; my used car is “too old”, compared to the six vehicles he has owned during the same period (I fall prey to wasteful gadgets, just not car related).
We, as a society, are simply not going to address extending the useful lifetime of our environment unless we suck it up and limit front-end consumption and waste. Period. We have defined “development” and the resulting “civilization” by the very -and messy- things we fool ourselves into believing technology can clean up, after we have long discarded them. I wish us luck, since some sort of a “universal conservation of everything” law appears (to me) being violated.
Great introduction but not much meat in this article so….
https://spectrum.ieee.org/ev-motor
Great article, thanks for the link!
It’s even the same picture…
Makes me think of those really really early radio speakers (pre 1950s) that had a field coil and a voice coil
Alternators also use a field coil, armature coil system with no PMs.
Yep! Can’t generate any electricity with an alternator without having at least a little battery power for the coil.
Makes me wonder how push-starting a manual transmission vehicle works. Some juice left in the batt box just not enough to turn the engine over?
Just try push starting an EV and you’ll see how important juice in the battery is
The idea is to get some momentum in the car, then ease the clutch gently to use that energy to help turn the engine over (without stalling). Your “flat” battery that isn’t able to provide enough cold-cranking arms to start the car on it’s own will still have some current available, and likely be able to turn the engine with a bit of mechanical help.
I don’t have the numbers, but the current requirement for the starter motor is vastly larger than that of the ignition system. A battery that can’t turn over the engine can still have plenty for the alternator/spark.
It will vary by the size of an engine, but an ignition coil usually draws amps in the low single digits. A starter almost always hits triple digits, so let’s say roughly a hundred times more juice (with a large spread of variation)
Exactly, it takes a lot of capacity to turn a starter motor (and everything attached to it) but even a nearky-dead battery can still provide a spark and get enough current going in the field coil for an alternator to start up.
I have bump-started a lot of vehicles in my life. Don’t ask. And I have indeed found a battery so dead it won’t even create a spark in the ignition system. I have also push-started things with magnetos, which is nice. You don’t need a battery there. It does involve some permanent magnets, though.
There were self-exciting dynamos that could be started with the remaining magnetic field in the iron core. Whether that counts as a “permanent magnet” is up to you.
A modern three phase induction motor can also be started as a generator that way when wired up as a generator. There’s some magnetic field remaining in the rotor that can induce a small current in the stator coils, bootstrapping it to create a stronger field.
Old timey electric motors were self-bootstrapping with a magneto – you just need to spin it a little bit and it generates its own field current.
so one can push start a Tesla!
see! I was right!
(as long as it’s a Tesla with an induction motor)
“A modern three phase induction motor can also be started as a generator that way when wired up as a generator. There’s some magnetic field remaining in the rotor that can induce a small current in the stator coils, bootstrapping it to create a stronger field.”
You could technically push-charge a Tesla by towing it with the regen brake on, but I’m not so sure the software allows that.
i think it’s cool that technology always operates at the bleeding edge. in batteries and motors, everyone wants the lightest / most powerful. no one is going to pay a 50% more weight penalty if they don’t have to. but if they have to (because rare source material runs out, for example), then suddenly that’s the new baseline.
in other words, we’ll burn that bridge when we come to it
Why?
I mean, in an EV sure, of course. But is that what is really important in every situation?
For example. If I had a farm or large yard with an extra out-building and I was installing solar… I think I would prefer to fill that building full of Nickel Iron batteries that will outlive my great grandchildren rather than a much smaller and sexier Tesla Power Wall that I’ll probably live to replace (at great expense) myself.
>Nickel Iron batteries that will outlive my great grandchildren
Which is exactly why no one will sell you such a battery. They know there’s no money to be made after the initial sale. Capitalism engineers fragility for the sake of profit.
(Yes, I know you can buy nickel-iron batteries. They have plastic cases and wear out in 10 years, intentionally.)
The second reason is that nickel-iron batteries are terribly inefficient and fickle to operate, and they generate hydrogen, so you wouldn’t use them unless you really had no other choice.
He’s a commie.
Of course you will have no other choice.
well it’s not always weight that is being optimized for but it’s always *something* that is being optimized for. time between failure, purchase cost, maintenance, size, charging complexity, whether it works in the winter. as for nickle iron, i don’t know why it’s not more widely used, but a quick skim of wikipedia shows that it was a contender for starting cars and it lost to lead acid a hundred years ago. that is to say, if lead acid wasn’t an option, people would have been a lot more interested in nickle iron batteries. they would still have wanted a starter battery in their car, and there would have been a lot more effort to solve the disadvantages of nickle iron. which is the point i was trying to make.
The problem with Ni-Fe is that it takes a huge overpotential to charge up giving it poor efficiency, it has poor power density owing to the slow reaction rates meaning you need big batteries to crank the starter, it self-discharges quite rapidly, and it consumes water as it bubbles up hydrogen gas. Lead-acid was far simpler, cheaper, and much better behaved as a battery goes.
The only thing going for Ni-Fe was its robustness and long life. Everything else about it was crap.
PMASynRM motors allow best of both worlds. I have 2 SynRM on my old Model S and no rare earth…
In the old old days, weren’t those called ‘induction motors’?
Induction motors are asynchrone motors. They are slower than the input frequency, “slipping”
I’m a big fan of PEV’s (Personal Electric Vehicles) and super excited that this research will trickle down into my space hopefully sooner rather than later. I’m to understand that koenigsegg has been working on a custom electric motor as I’m sure many other companies are. In the end the ability to produce a whole lot of torque in a really small package will be everywhere and make the world a much more fun place to be. BLDC is already in the newer power tools, etc.
At the smallest scale I’m not sure any of the not rare earth options really work effectively. Far as I know none of them scale down to that sort of size very well – though I can’t claim to know that for sure. That said when you need virtually no magnet for a motor that small anyway I don’t think the benefit really comes through either.
The motors mounted to electric scooters seem plenty zippy to my eye. Do they need to go much smaller?
That is all from a motor that is pretty small scale already – my comment is I don’t think this sort of research (at least currently) scales down to the PEV size motors very well – it all starts to really work once you get into counting in horsepower or kilowatt to my understanding – it scales up well but not down to where PEV motors sit. There you are talking perhaps 500 watt, and usually much less than that (In the EU 250 is the max legally) . Its not about more performance its just that rare earth magnet free motor work really well at these small scales.
If you’re one of them believers, and don’t like the gargantuan powers/sizes that EVs are maxxing towards, then what you want is electric scooters with swappable batteries (like Gogoro), with an enclosure for rainy days.
And no need for a long seat for the missus, cause you’re against children anyway.