Ev Motors Arent Done Inside The Next Wave Of Ev Drive Units

TITLE: EV Motors Aren’t Done: Inside the Next Wave of EV Drive Units CHANNEL: Electric Vehicle Society DATE: 2026-06-03 ---TRANSCRIPT--- EVs feel effortless to drive, but that feeling is engineered. Most EV conversations focus on the battery. In this video, we look at the part that actually turns electricity into motion, the motor and the drive unit. Paul Turnbull, technical specialist at Monroe and Associates, takes us inside EV motors and drive units. How they work, how designs are changing, and why this technology matters for the next generation of electric vehicles. Paul, take it away. It’s great to have you here. We were chatting a little bit before we began the uh recording for the webinar, and I think you have some pretty interesting things to share. So, I’m just going to uh as I often do, I’m going to get out of the way and uh let you uh have at it.

Yeah, I’ll have to get my cat out of the way as well. No, the cat’s welcome. We we welcome cats in this show all the time, so no, don’t worry about that. Uh so we’re going to talk a little bit about powertrain trends for electric vehicles and uh going to cover a little bit about batteries and then I’m going to dive into uh motors and the trends that we’re seeing in electric motors um in the market today and where that’s likely to take us in the near future um out into 2030 or so. Um so what from from our perspective at uh Monroe Engineering uh Monroe and Associates, we try to you take apart just about all of the uh various OEMs hardware and have a look at what people are doing, what uh the automotive OEMs are doing, what the suppliers are doing and uh report on the trends that we see. The elephant in the room with um electric vehicles is the battery. Uh batteries are too big, they’re too heavy, and they’re far too costly. And that has always been true. But uh since 2018, 2019, the batteries have been coming down. The prices of batteries have been coming down. And I think one of the most uh one of the most exciting trends that we are seeing is um in the trend towards affordability. And that’s something that is going to be absolutely key for the near-term future. And I know it’s near and dear to most uh car buyers hearts, especially right now as we’re seeing gasoline costs go through the roof and maybe people are considering going to an EV for the first time. There are some new things that are happening that are may help us. So at the moment for the past couple of years, this red line are passenger vehicle battery at the prices at the pack level. And these are the prices that the original equipment manufacturers, the car manufacturers are paying uh not what uh somebody that is going to Amazon to try to pay. uh the OEM equipment manufacturers, they’re currently around the last year running right around $100 $100 per kilowatt hour to pay buy their battery pack and usually of course they buy the components and build the battery pack. Um but it ends up costing them about that. There is a new technology, a new chemistry that is now in mass production and the largest manufacturer in the world, CL or cattle has announced that on May 8th that they are dramatically increasing their production of [clears throat] these sodium ion batteries and they are currently selling them at a price point that makes for automotive OEMs their battery costs are in the neighborhood of $60 per kilowatt hour and it’s likely going down from there as this new production gets online uh at the end of this year. And so we’re going to see sodium ion batteries in in electric vehicles in the near future. And it’s particularly nice for those of us who live in the north uh because sodium ion battery chemistry works at sub-zero temperatures. Doesn’t suffer the same issues that lithium ion batteries have at very low temperatures and so their winter range will be a little bit better than it is today. Um, there are still other issues that cause winter range to suffer, but uh, at least the battery will still work as well as it did at summertime. So, that’s one of the great benefits of this. It works better and it’s less costly. And that’s I think if you get nothing else out of this talk, then that piece of good news is uh, something to to focus on. There’s all kinds of other advancements in the battery region in terms of uh solid state and lithium ion batteries and and in various chemistries that use it are not done yet and there’s room for them to grow. But uh this particular battery chemistry is likely to start seeing pretty significant adoption particularly at the uh lower price point vehicles and that’s going to be good news for EV buyers. There’s other trends in uh batteries and and the the technology in general uh that drives the car. Um, inside the car, you need to think about what voltage you’re going to run your system at. So, you can choose uh at these days, the typical voltages are either 400 or 800 volts. Most of the charging infrastructure uh both in Canada and US are still at about the 400 volt level. And so if you’re going to choose to go to 800 volts, then you have to do some special engineering to be able to boost that voltage up to 800 to charge your battery, which takes a little bit of extra hardware uh and that can lead to higher cost. So we’re seeing 800vt hardware, it’s it’s expanding. Um more and more vehicles are adopting it. Um there is an efficiency benefit and there’s a huge charging speed benefit if you are at a uh 800volt charger. But if you’re at a a legacy 400 volt charger as most the chargers are then there’s very little benefit uh to being at 800 volts. Uh we are seeing this trend. It’s it’s continuing to grow but you look at the values it’s in the 40% range. we expect it to go to 50% or so but then kind of level off there because um what’s happening at the bargain end the value end of the EV supply chain is that most of them are staying at the 400 volt level uh rather than pay the premium to go to 800 volts because affordability is probably the number one factor that’s driving new EV designs um at the automotive OEMs. Yes, we’re seeing 800 volts, particularly at the premium levels for vehicles, but in the affordable levels, uh that are going to stay at 400 volts for the foreseeable future. Um so that’s one of the key trends in batteries. And finally, there’s been a lot of discussion about going from how batteries are built and again the the driving force each automaker has to face is faced with reducing complexity, reducing cost, reducing weight and trying to reduce this overall size of the batteries. And the way that most of the companies are using to get there is to move from what they used to do which is cell they put the cells into a module and then they build the pack up with modules. So that it’s cell to module and then module to pack. That unfortunately does lead to increased complexity, more parts, and a little bit higher cost. But there’s some benefits. And when you’re going with uh modules, each individual module can be kept below 50 volts. So, it makes battery handling in the plant much easier and safer. And it makes serviceability a thing. When you go directly from sell to pack, then you give up serviceability and Tesla is the extreme example of that where they go directly cell to pack and then they pour in a urethane foam adhesive that uh locks it all together and makes the entire pack um essentially disposable. However, it makes it very robust and so the reality is that if it lasts for a million miles, then you don’t necessarily need to service it. Uh so that’s the strategy that Tesla has been using. We see BYD um going this direction as well. And so most of the the biggest automakers are going in this direction. Although we do see some of the automakers sticking with a cell to module to to pack strategy that that keeps the serviceability and also a kind of uh flexibility for various size battery packs a part of the design. So that’s what the the last of the battery trends that I wanted to talk about before we get into the motors. And again the the the thing we want to talk about here that is complexity. It’s weight. It’s cost overall and for the motor the way the best way to get cost out of the vehicle is to make the motor more efficient. Because if you can go the distance with less battery, uh even if it costs an extra dollar or two in the motor and gearbox, you’re going to save 10 or $20 in the battery uh by reducing your battery size. And it’s a it’s a a virtuous cycle where if you can reduce the battery size, you reduce the battery weight which reduces the power required to accelerate the vehicle which helps you reduce the motor size and so on. And so efficiency is absolutely the key to getting the cost out of EVs. Efficiency in the motor and drive unit. So motor, inverter, and gearbox. back when I started in uh EVs, which was around uh 1999, everybody was doing EVs at the time, uh and from then up to about 2010. It was sort of the wild west and everyone was doing their own thing. The way it was done is to to build a motor and then attach it to a separate gearbox and then have a separate inverter which was mounted separately in its own box elsewhere in the vehicle. Today we’re combining all of those things into one and so it reduces the number of parts. Uh so the casting for the motor for the drive unit uh the casting for the motor also houses the gearbox and is the bottom half of the inverter housing. And so you end up saving money when you bring it all together. um you have you can eliminate those cables which do nothing for you but produce loss and so the shorter the runs the better the efficiency and the less um electromagnetic interference. So these motors when they’re pulling hundreds of kilowatts become little broadcast stations and so you’d like to keep all of that happening inside electrically conductive aluminum box. And so when we put it all together, integrate it together, that dramatically improves the um electromagnetic interference issues that they used to have in EVs. So this is one of the trends that we’re seeing. Just about every manufacturer now has settled on this type of design. And I’m going to spend a little bit of time um talking about the different parts because maybe some people are not so familiar with seeing an exploded assembly of a drive unit. There are two parts of the motor. This is the rotor. This is the part that spins. It has the permanent magnets in it. And it fits inside this which is called the stator. The electric current flows through the stator. And you might be able to see there’s three uh terminals on the stator. So you put electric current into the stator, it becomes uh an electromagnet essentially and that attracts the magnets of the rotor. It actually I should say both attracts and repels the magnets of the of the rotor. And then what you do is is by putting threephase sign current AC current into the stator that electromagnetic field rotates. So the stator is stationary hence its name. it uh but the magnetic field in it rotates and when it rotates then the uh permanent magnets of the rotor want to rotate and follow the magnetic field in this in the stator. So that’s essentially how the a motor works. Uh you have a a a rotor with permanent magnets and a stator that you induce a rotating magnetic field in. That is the big invention that um Nicola Tesla is credited with. There were multiple people who came up with the invention roughly the same time but he is generally credited with the invention of the rotating magnetic field in a uh stationary stater and that is the key to making a brushless motor. The three-phase rotating magnetic field uh was actually perfected by uh Charles Steinmets who was the guy whose technology created General Electric. Uh so that’s actually the the rotating magnet type of rotating magnetic field that we use in motors. So that’s the motor. It fits inside this big housing which is a a big aluminum casting. In this case, um there’s oil that is u it’s just regular automatic transmission fluid that circulates inside the this machine to keep the rotor and stator cool. Other machines use water that circulates around the outside. It’s mostly water with a little glycol uh to keep it from freezing. It rotates or it flows around the outside of the drive unit. So the the this casting is used uh partly for cooling the motor. On the top, this has two components. Um [clears throat] this is called the inverter. And what this thing does is it takes the electricity from the battery which is DC uh positive and negative and it goes into the inverter and the inverter turns that into three-phase AC electricity which is what the stator needs to make the rotating magnetic field. And so that’s what the that’s the other major component motor inverter. And then the last component is the gearbox. And this is a a typical kind of a gearbox for electric vehicles. It’s a one it essentially has one gear, one speed. Uh so you’re it’s like you’re in first gear all the way from zero to max speed. And that’s possible because this motor, this type of motor has a really wide operating region where it’s got high efficiency. Uh so you get high efficiency both in at at the city driving and on the highway with one gear. And then there’s just a cover to to keep this in. Um this part of the gearbox is called the differential. Every car has a differential. It allows the the the two powered wheels to spin at different rates. So, if you’re going around a turn, the inner wheel can spin a little slower than the outer wheel. And that keeps your tires from u losing traction during a turn. And so, that’s a part of the gearbox uh of a of a electric motor. So, just to give you a feel for what these parts are, just about every um electric motor or electric vehicle manufacturer has converged on a design very much like this. Another thing that they’ve converged on is the way the stator is wound. So, for a hundred years, sters were wound using something called stranded wire. And so you see bundles of very fine strands of wire are put into slots. Um you can kind of see the slots in the stator here where I’ve cut off the ends of the windings. So you can look and see there’s lots of uh this case 50 different 50 individual wires in each slot. So this is how motors have been made for a very long time and it’s a perfectly good way to make motors. If you use square wire, you can pack more copper into the slot. And so you have more copper and less air. And it’s this is why we do it just because you need to minimize the winding resistance. When you’re putting hundreds of amps into the windings, they’ll get hot. And the uh the amount of energy that you lose is proportional to I 2 times the resistance. I being the electric current comes from the French word for electric current because of ampier the guy who whose name comes with he was a French engineer and uh so he’s created this and so we use the uh French word for electric current to give us I uh for the current in the stator. If you can get the resistance as low as possible, then you reduce the losses in the motor, you reduce the heat. And again, that means you can go farther on the same amount of battery or use less battery to go the distance you want. And so going to square wire is a definite improvement in in getting the most efficient motor uh possible. Cramming as as much copper into the slot as possible. This has become less costly for manufacturers because uh the machine tools for building motors in this way with what they call hairpin square wire. this this type of machine has gotten much less expensive. There are now far more suppliers that are out there building motors and building equipment to build motors um using this technology. Um and that has been a deliberate choice by the various um OEMs, General Motors among them, training suppliers, essentially giving away this technology. A lot of this is patented, but they’re giving away the technology in order to get more suppliers to be capable of delivering this this equipment. So, it drives the prices down for everyone um including the end customer. And so, that’s one of the things that u this type of winding technology helps. And because we’re seeing uh this this improvement and that in both the efficiency and the cost um that’s driving just about every manufacturer to abandon the u tried and true method of winding sters to use this new method of hairpin winding. The same thing is happening uh in the rotor. we’re seeing uh the rotors converge [clears throat] on a single design. So over the last 20 years um there have been a lot of different geometries and technologies used for making permanent magnet rotors. But now um in the last four or five years almost every manufacturer has converged on the same geometry for how to arrange the the magnets in a permanent magnet rotor. And what we’re seeing is this type of double V. So there are two the magnets are put into these slots. I’m these are cross-sectional views of of a rotor. And so the magnets are held out here near the outside diameter of the rotor and they’re put into these two V-shaped slots that just about every manufacturer is using. And then inside this is where the shaft would go. And this the um the one thing that’s different from one motor to the next is the arrangement of these holes here. And there those are just for reducing weight. The outside portion contains the the magnets. those this double V shape and they use this shape because it gives the the motor a very wide and very tunable adjustable efficiency range. So the it gives great efficiency at low speed and great efficiency at high speed. And by adjusting it’s not adjustable in real time, it’s adjustable in the design phase as you’re designing a new motor. You put these magnets in and you you try you optimize the design uh using many many different geometries. Uh and this type of topology gives you an excellent adjustable adjustability in the design to achieve just about any torque speed envelope that you need for your various the various vehicles. And so that this is one of the things that’s driving the OEMs, the various automakers to make these uh uh motors with this type of a rotor. Okay. And I did want to end with a little or wrap up here with a look at what’s coming. So almost all of the motors and so let me go back to that statement I made before. Almost all of the manufacturers seem to be converging on radial flux interior magnet synchronous motors with this double V magnet uh topology and bar winding on the stator. And as soon as you see a technology where everyone’s copying everyone else and everyone has pretty much the same design, that is a technology a sector in the business where it’s ripe for disruption. So now is the time or in the next few years we I would expect to see a disruption in the electric motor market. And of all there’s several potential possibilities. Um one of them is an old technology that uh we’re seeing a couple of companies adopt and that is a a wound field synchronous machine. So you get rid of the permanent magnets altogether. The rotor becomes has electromagnets in it. Um, and then you solve the problem of getting electricity into a spinning rotor. That’s usually done with brushes in the least expensive way, but there’s also a way to do it using a rotating transformer. And BMW is doing that. And so there’s there’s a potential there for a a disruptor if neodymium magnets become unavailable due to a political disruption. And the neodymium magnets are primarily sourced from China. And so a political disruption in China could interrupt that uh supply chain. And then that would make the the wound field rotor machines become much more prevalent in a real hurry. And so we’re seeing Nissan and BMW are in production now with uh Woundfield synchronous motors in anticipation of the potential for disruption in in the permanent magnet supply chain. most of the other manufacturers, you know, the the permanent magnet motors are just so efficient and so power dense that it’s really difficult to justify going away from them in the short term. There is however one this technology and it’s on this page here and that is axial flex motor technology. We have on the screen here is a competitor uh that’s making it now. Yasa is the name of the company. It’s a British company that is has been purchased by Mercedes-Benz and they are currently making this motor. This is the YM360 and it’s in production now. It’s in a hybrid application. Where this motor sits between the internal combustion engine and the transmission uh where typically the torque converter would sit. Since this technology is extremely thin in in axial length makes it fits in there very nicely. It packages in that location very well. Um and you can fit an enormous amount of torque. So the way that this technology works and I have a video out on it uh when row live if you want to have a a look at that. This type of technology allows you to get more torque density than you can get with a interior magnet synchronous machine using a radial flux approach which is the the typical type of motor that uh most companies are using now. So because you can fit more magnetic field and more torque into a smaller package that also leads to a lower cost because um ultimately at high volume electric motor cost is driven by the amount of steel, the amount of copper and the amount of neodymium that you put in these motors. This type of motor uses about the same amount of neodyabium and about the same amount of copper because it’s carrying about the same amount of current, but it uses dramatically less steel. The fact that it’s using dramatically less steel makes it significantly less costly and significantly lighter weight. Um, and again, package size is is much smaller. this particular motor technology because of those benefits is likely to become is is probably the most likely disruptor in the market uh in 2030 and beyond. I think until up until 2030, we’re going to continue to see the interior permanent magnet synchronous motors that pretty much everyone is going with um just because of the entrenched manufacturing capacity that uh is already toled up and cranking out motors. So, but we will see this technology starting to come in. We’re we’ll see it in the high performance vehicles where weight and size are at a major premium. Um and then it will eventually come down in into the regular vehicles that we’re seeing that uh the rest of us are able to afford and purchase. Thanks again to Paul Turnbull for joining us. If you found this discussion useful, please like the video, subscribe to our channel, and share it with somebody who wants to better understand where EV technology is heading. And to go deeper into another major area of EV innovation, watch Toby Bond’s discussion on recent battery developments. right here. Thanks for watching.