You're right about the verbiage being amusing.

All big generators have an exciter coil that is used to generate the magnetic field. It has the advantage of allowing voltage regulation through adjustment of the field, rather than after the fact, which would be far less efficient.

In both motors and generators, there is an efficiency hit related to the need to supply power in order to generate the field, but when you scale up the system, it actually becomes more efficient to use the electromagnet. With the rare-earth mineral shortage, it makes even more sense.

Long ago, when I was in Cub Scouts, one of the projects was to build an electric motor. The parts list was:

1. a plank to form the base

2. several 6 inch nails

3. wire

4. a tin can (as a source of sheet metal)

5. tape

No magnets. But it worked perfectly fine when connected to a dry cell. Adventurous science lad that I was, I decided it would work better when connected to AC. So I attached a power cord and plugged it in.

A loud vibration ensued, and then it burst into flames. My mom wasn't happy.

What advantage do permanent magnets provide that it isn't the case that all motors are made without them?

Not quite true: you're also limited by the mechanical strength of your windings and core (this is the upper limit on superconducting magnets like at CERN and in fusion plants).

The cheapest EV model Renault sells is around €20K, the cheapest BMW EV is around €65K.

It's safe to say the companies are not in the market bracket, no?

Which is quite the contrast to Mercedes new axial flux electric motor, which goes all in on rare earths- the design relies on the highest end high-grade permanent magnets.

Still, presumably Mercedes ambitions are for few motors than BMW or Renault.

It's technically not a brush but a slip-ring. The design of these motors is very similar to automotive alternators, just scaled up 100x (in terms of power).

"Brushless DC motors" are good because brushed DC motors are constantly switching polarity, which causes arcing of the brushes, which causes wear. The brushes are not there to energize the rotor; the rotor is just magnets after all. The brushes are there to tell the stator to change polarity.

Brushless DC motors don't arc -- because they switch stator polarity with electronics that sense the position of the rotor without rubbing parts. (They can also fine-tune the stator current spikes to make the motor very efficient over a wide speed range, which brushed DC motors cannot do.) The lack of arcing is more important than the fact that they don't have rotating contact points.

Brushed AC motors have rotating contact points (slip rings) but they don't arc (ideally), so the contact points don't degrade as fast as brushed DC motors do. But they do carry a lot of current because their purpose is to energize the rotor. Brushed AC motors are not ideal, but making an AC motor "brushless" is not nearly as big a win as making a DC motor brushless.

Wait. You're saying DC motors require current that's constantly switching polarity? So they're sort of really AC internally?

Yep. All motors require constantly changing current. The distinction between AC and DC motors is whether you feed the motor externally with current that is already alternating sinusoidally, or whether the motor itself turns external DC into some kind of AC.

Also known as: “we removed the rare earths and added software.”

Could be wrong, but AFAIK the CATL Sodium batteries haven't yet hit LFP pricing.

You are unlikely to see a vehicle with sodium batteries until after that happens, and it needs to be significantly less than LFPs as you Na batteries have more weight per Wh. I believe they also have a shorter lifespan (but not NMC short). Edit correction, looks like CATL is promising 15000 cycles, which is much longer than LFPs which usually come in at 7000 to 10000.

It seems far more likely to me that if the Na prices tank, you'll probably first see them deployed as grid and home battery solutions.

Unlikely.

EESMs are primarily manufactured by European OEMs (ZF, MAHLE, Schaffler, AEM) and their Indian JV partners (Sona Comstar, Sterling, and the India branches of the OEMs listed). Both have been blocked via export controls from accessing battery tech from China over the past few years, and a major reason for the push for EESMs was for an ex-China supply chain, especially after China began export controlling rare earths to the EU [6].

Additonally, Chinese and American EVs tend to use PMSMs unlike European and now Indian EVs. Also, the EU is cracking down on automotive exports (cars and OEMs) from non-FTA states as part of the EU Industrial Accelerator Act (which btw has made China go ballistic [2][3][4][5]).

On the other hand, they will most likely use Japanese or Korean solid-state batteries as Idemetsu Kosan is in the process of mass producing them [0][1] as is LG [7], and both Japan+SK are FTA partners with the EU.

[0] - https://www.chiyodacorp.com/en/projects/solidelectrolytefaci...

[1] - https://battery-tech.net/battery-markets-news/idemitsu-kosan...

[2] - https://www.globaltimes.cn/page/202605/1361926.shtml

[3] - https://www.globaltimes.cn/page/202605/1362200.shtml

[4] - https://www.globaltimes.cn/page/202605/1362161.shtml

[5] - https://www.ft.com/content/5903318c-319b-426e-b05d-062f7620f...

[6] - https://www.reuters.com/world/china/eu-lawmakers-rebuke-chin...

[7] - https://blog.lgchem.com/en/2026/03/25_solid_state_battery/

No, and it was mentioned by the consortium of European cars manufacturers after the joint press release with Der Leyen herself: the implementation of factories and research centers in India is solely to be able to sell on that market. It is the exact same process that happened with China in the past. The exact same also happened with Airbus.

You are also wrong on the market importance for Renault. For 2024, France was the biggest, followed by Italy, Turkey, Spain, Germany, Brazil, UK, Morocco, BENELUX, Romania, Poland, Netherlands and... #13 India with 0.9% market share...

Supply chains didn't change at all, in fact it did the opposite, and Europeans won't rely on anything Indian made for the near future, as local re-industrialization is already acted on and even accelerated since the pandemic.

Production numbers across all manufacturers even Volkswagen (which was unexpected) show the number of cars manufactured in Europe increased in the past 2 years.

Electric cars in Europe mostly come from China, the US and European brands. Nothing Indian-made, not even parts.

Not sure why this was voted down, it was the most useful comment here.

does Nissan still use these motors, the car in the linked article has been discontinued, and then only real info I can find on their site about the leaf is about their ROCKIN' bose sound system/s

European and Indian manufacturers/engineering are definitely not in the same category though.

> The Ariya was discontinued in North America but is still manufactured and sold in Asia.

The Nissan Ariya is NOT discontinued in North America. Nissan no longer sells it in the USA because of Trump's tariff war.

The Nissan Ariya is still sold in Canada.

what is a prsm? Do you mean pmsm?

EVs in the US and China tend to use PMSMs, though GM, Stellantis, the DoE, and the DoD are funding an EESM startup [0]

[0] - https://nironmagnetics.com/

Yes: IIRC some large generators work exactly like this, as the energized rotor gives a lot more flexibility in managing frequency and power output.

After watching a Munro video about it, I see your point. In the motor shown, the rotor gets its magnetic field simply by inducing a current and a field in it in reaction to the stator's field. There are no electromagnets in the rotor like I expected. In that case, I'm not sure either... I'd say more likely than not but it's complicated since the stator basically needs to induce a field and at the same time recover energy from the field that comes back from the rotor. I would further guess that the phase shift between the two components makes it possible to treat them separately.

Previous comment: Don't see why not - the "field" coils (the ones that replace the permanent magnets) need to be energized, which can initially come from the batteries if necessary.

It was a dude with motors on a table with a flip board. No animations. No diagrams. When it got to the point about having one of each motor, and using the best, he then said that you use the permanent motor even when the other makes sense. Ok, well then why have the two different kinds of motors? No answer. Just handwaved. If you can't use the induction motor when its most efficient, because thats when the permanent motor is causing spin loss, why have the induction motor at all? No answer.

So. Analog presentation. Actual motors on a desk with a flip chart. No animations. No internal visualizations. One page had diagrams that would have been better super-imposed (or hey, animated). Then one page the begs questions with no answers given.

There is something... weird about this. this tech has existed.... a long time. And I am not familiar with what is common in electric cars so may be missing something obvious but thought this was already how it was done. let me explain my limited understanding.

With ac motors electromagnets can be used in the rotor. there is even a super clever way to do it where the electromagnet in the rotor is driven wirelessly via induction. there are some downsides but having no physical sliding electrical connection to the rotor is a huge upside. The ac can be dynamically formed from DC via high speed switching(transistors, in industry often called a VFD).

Due to the upsides of ac induction motors I sort of assumed this was already what was found in cars. I am a bit surprised to find out there were rare earth magnets in the first place.

They even use regular carbon brushes to supply power to the magnet. Munro has a teardown video for a similar motor for Nissan: https://www.youtube.com/watch?v=BFmp9ODkCA8

So does it consume significantly more electricity?

no, but requires introduces brushes (slip-rings really) which is a wear item

They are electronically commutated. The stator field is more or less variable AC.