Just ordered a Bolt

[MX793]

Because it's impossible for a supercharging standard to be shared among manufacturers

Why?

They make these amazing devices called DC to DC converters.  If you have a known DC power input (or range of inputs), they can convert that to a single output.  If the industry decided that 480VDC, 200A would be a recognized fast charge standard, every automakers would be able to spec a DC-DC converter that would allow them to fast charge using that input without having to change batteries or more core parts of the car.  Just as every EV today has an onboard AC/DC converter that allows them to accept AC power at a range of standard voltages and currents (both US and international).

[CaminoRacer]

/sarcasm, guys

[GoCougs]

Why?

They make these amazing devices called DC to DC converters.  If you have a known DC power input (or range of inputs), they can convert that to a single output.  If the industry decided that 480VDC, 200A would be a recognized fast charge standard, every automakers would be able to spec a DC-DC converter that would allow them to fast charge using that input without having to change batteries or more core parts of the car.  Just as every EV today has an onboard AC/DC converter that allows them to accept AC power at a range of standard voltages and currents (both US and international).

The hitch is on-board 100+ kW conversion is virtually impossible because of size and weight - at least a few hundreds of pounds and the size of a fridge. Simply Google the interior of a Tesla supercharger cabinet or commercially available DC power supply of 100+ kW.

Tesla supercharging uses 400 VDC and not 480 VDC, and there is a very good reason why: it's easy (cheap) to get 400VDC from 480VAC 3 phase. One leg from 480 = 480/sqrt(3) = 277, and the peak of the 277 sine wave is 277*sqrt(2) = 393 V, which is clipped by way of diodes, to get ~400 VDC. Thus, left to their own devices, any automaker interested in supercharging would also highly likely use 400 VDC (at least in the US).

But again, voltage is not voltage and current is not current. There is a lot of smarts needed in charging batteries, and that resides in the supercharger station, and it expects to see Tesla batteries, just like you'd not be able to yard out the AC charge system of a Bolt and install it in a Leaf.

So again, we Catch-22 ourselves back to supercharging "standard." Standard connectors? Standard voltages? Standard currents? Standard battery chemistries? Standard battery designs? Standard charging comm protocols? Sure, that can all be done, but as demonstrated, it's not easy and would thusly hamstring EV makers (esp. slowing the pace of innovation). Tesla could not have rolled out supercharging like it did if it had to coordinate with Nissan, Chevy and Toyota

TL;DR - standards are a bad idea, or, at least forcing EV makers to adhere to them is, and there are very good technical (and business) reasons as to why Tesla (and other EV makers) are doing what they are doing, and it's never to be difficult or cutesy or w/e.

[CaminoRacer]

I don't think anyone has said that Tesla should be forced to use a standard, just that an industry standard is likely to form once the vehicles become commonplace.

[12,000 RPM]

Standard connectors and voltages are probably enough. Contrary to Cougsian science voltage is voltage and current is current. If Tesla wants to run some proprietary thing on its own, cool. But different battery protocols would be like every manufacturer only being able to run its own proprietary gasoline. Completely unecessary and of no benefit to anybody.

[GoCougs]

I don't think anyone has said that Tesla should be forced to use a standard, just that an industry standard is likely to form once the vehicles become commonplace.

MX793's post claimed that a supercharging standard could be had by way of on-board 100 kW+ converters. That will never happen with today's technology - too big and heavy, plus 400 VDC is easy to be had, by anyone, as shown, and just in general, there is no easy or certain path to an industry supercharging standard (well, other than Tesla licensing its battery and charging tech).

[CaminoRacer]

I assume that electric cars will be commoditized to a large degree. I don't see why each manufacturer would have their own motors when they're the same basic thing, just with different torque ratings.

[AutobahnSHO]

Standard connectors and voltages are probably enough. Contrary to Cougsian science voltage is voltage and current is current. If Tesla wants to run some proprietary thing on its own, cool. But different battery protocols would be like every manufacturer only being able to run its own proprietary gasoline. Completely unecessary and of no benefit to anybody.

+1

[GoCougs]

I assume that electric cars will be commoditized to a large degree. I don't see why each manufacturer would have their own motors when they're the same basic thing, just with different torque ratings.

Standardizing on motors is even more unlikely than standardizing on a supercharging protocol.

There is huge variation in electric motors in general - AC vs. DC, brush vs. brushless, permanent magnet vs. field wound, synchronous vs. asynchronous, voltage level, phase count, pole count and switching frequency, to name just a few.

There is already notable motor variation in the EV market. The Leaf and Bolt both use an AC synchronous motor and the Models S/X use an AC induction motor (and the motor types are neither compatible nor equivalent, especially when it comes to powering them).

[Laconian]

Yeah, I think we're still in the Precambrian explosion of EVs. There is a lot more freedom and flexibility for electric component selection and placement vs. ICEs.

[GoCougs]

Standard connectors and voltages are probably enough. Contrary to Cougsian science voltage is voltage and current is current. If Tesla wants to run some proprietary thing on its own, cool. But different battery protocols would be like every manufacturer only being able to run its own proprietary gasoline. Completely unecessary and of no benefit to anybody.

Today, each EV already has its own "battery protocol." For EVs that plug into AC to charge (= NOT fast charging), the user is only insulated from it - the "battery protocol" is buried inside the car, downstream of the AC input plug after it is converted to DC. However, in order to supercharge, high current DC needs to feed directly to the batteries, thusly moving the "battery protocol" to the external charging station. It's completely necessary and a benefit to everybody (= specific design for specific purpose + quicker pace of innovation).

[CaminoRacer]

Standardizing on motors is even more unlikely than standardizing on a supercharging protocol.

There is huge variation in electric motors in general - AC vs. DC, brush vs. brushless, permanent magnet vs. field wound, synchronous vs. asynchronous, voltage level, phase count, pole count and switching frequency, to name just a few.

There is already notable motor variation in the EV market. The Leaf and Bolt both use an AC synchronous motor and the Models S/X use an AC induction motor (and the motor types are neither compatible nor equivalent, especially when it comes to powering them).

But does the end user care?

I guess I just associate EVs as more similar to consumer electronics, where AFAIK most if not all parts are shared, just in a slightly different configuration. So companies might use different types of motors right now, but eventually they'll find which is best and all use that. I suppose there are still trade-offs in range and power, but advanced battery tech may make that irrelevant for the average user.

[CaminoRacer]

Today, each EV already has its own "battery protocol." For EVs that plug into AC to charge (= NOT fast charging), the user is only insulated from it - the "battery protocol" is buried inside the car, downstream of the AC input plug after it is converted to DC. However, in order to supercharge, high current DC needs to feed directly to the batteries, thusly moving the "battery protocol" to the external charging station. It's completely necessary and a benefit to everybody (= specific design for specific purpose + quicker pace of innovation).

Imagine if every car needed its own fuel pump nozzle. What a nightmare! In order for EVs to become the main mode of transportation, some sort of standard is needed. Otherwise every recharging stop will need twenty different charging stations.

[MX793]

The hitch is on-board 100+ kW conversion is virtually impossible because of size and weight - at least a few hundreds of pounds and the size of a fridge. Simply Google the interior of a Tesla supercharger cabinet or commercially available DC power supply of 100+ kW.

DC-DC converters can get pretty compact.

https://www.tame-power.com/en/dc-dc-power-converter/dcdc-converter-60kw-300-400v

^^^This one is 60kW and can step 500-700VDC down to 300-400VDC (or vice versa, it's bi-directional).  It weighs less than 50 lbs and takes up less than a cubic foot.  Yeah, it needs liquid cooling pumped through it, but so does Tesla's battery during charging.  Two of these in parallel could provide >100 kW of 400VDC, stepped down from some higher voltage DC source.

[GoCougs]

Yeah, I think we're still in the Precambrian explosion of EVs. There is a lot more freedom and flexibility for electric component selection and placement vs. ICEs.

For quite some time I've been of the mind that what are commonly referred to as "frameless" motors in industry will make their way to EVs. Basically, the motor is mounted in the wheel, and the axle is the center of the rotor. Imagine the packaging and efficiency gains.

[AutobahnSHO]

For quite some time I've been of the mind that what are commonly referred to as "frameless" motors in industry will make their way to EVs. Basically, the motor is mounted in the wheel, and the axle is the center of the rotor. Imagine the packaging and efficiency gains.

totally sweet!

I invented hybrid cars in 1982. I was in second grade, bored in class and drew a car which used electric motors to go and generator to stop. Showed it to my dad (elementary school teacher and lover of all things computer geeky), he said I would need energy to go to start with. I wasn't thinking of plugin at the time, so I told him I'd put in a gas motor to get going at the start. He said that unfortunately electric generators weren't efficient enough, maybe someday......       

For reals that is a true story. Wish I had the picture.

[FoMoJo]

For quite some time I've been of the mind that what are commonly referred to as "frameless" motors in industry will make their way to EVs. Basically, the motor is mounted in the wheel, and the axle is the center of the rotor. Imagine the packaging and efficiency gains.

Unsprung weight may be a challenge.

[Laconian]

How is that different than a hub motor?

Unsprung weight may be a challenge.

Good point, though it looks like it could take the place of brakes?

[FoMoJo]

How is that different than a hub motor?

Good point, though it looks like it could take the place of brakes?

True, but placing the assembly inboard could resolve the problem without too much difficulty.

[GoCougs]

DC-DC converters can get pretty compact.

https://www.tame-power.com/en/dc-dc-power-converter/dcdc-converter-60kw-300-400v

^^^This one is 60kW and can step 500-700VDC down to 300-400VDC (or vice versa, it's bi-directional).  It weighs less than 50 lbs and takes up less than a cubic foot.  Yeah, it needs liquid cooling pumped through it, but so does Tesla's battery during charging.  Two of these in parallol could provide >100 kW of 400VDC, stepped down from some higher voltage DC source.

Actually, that is only the core component of a converter - it has to be integrated to be usable. That is the thing buried inside a fridge-size cabinet.

A good portion of what you pay for with "converters" is cooling. Even small such devices' size/weight are dominated by fins and/or fans and/or heat sinks. Here, that unit is liquid cooled, and cooling 120 kW would rival the cooling system of at least a motor bike. This is why a 120 kW power supply like Tesla's own supercharger is about the size of a fridge - whether they have liquid cooling, fan/AC cooling or just a bunch of mass and/or surface area to dissipate waste heat.

[GoCougs]

But does the end user care?

I guess I just associate EVs as more similar to consumer electronics, where AFAIK most if not all parts are shared, just in a slightly different configuration. So companies might use different types of motors right now, but eventually they'll find which is best and all use that. I suppose there are still trade-offs in range and power, but advanced battery tech may make that irrelevant for the average user.

Imagine if every car needed its own fuel pump nozzle. What a nightmare! In order for EVs to become the main mode of transportation, some sort of standard is needed. Otherwise every recharging stop will need twenty different charging stations.

Imagine if every car needed its own fuel pump nozzle. What a nightmare! In order for EVs to become the main mode of transportation, some sort of standard is needed. Otherwise every recharging stop will need twenty different charging stations.

IMO it's a big mistake to use consumer electronics or ICEs as analogies - the tech just doesn't equate.

[GoCougs]

How is that different than a hub motor?

Good point, though it looks like it could take the place of brakes?

Same as a hub motor.

By the time such motors are implemented the next evolution of MagneRide, active electromechanical suspenion, will be here:

https://www.youtube.com/watch?v=3KPYIaks1UY

[MX793]

Actually, that is only the core component of a converter - it has to be integrated to be usable. That is the thing buried inside a fridge-size cabinet.

A good portion of what you pay for with "converters" is cooling. Even small such devices' size/weight are dominated by fins and/or fans and/or heat sinks. Here, that unit is liquid cooled, and cooling 120 kW would rival the cooling system of at least a motor bike. This is why a large DC-to-DC converter (or transformer or power supply) like Tesla's own supercharger is about the size of a fridge - whether they have liquid cooling, fan/AC cooling or just a bunch of mass and/or surface area to dissipate waste heat.

Um, no.  That is a fully functioning, stand-alone, self-contained 60 kW DC-DC converter along with necessary control circuitry to hook it up to a CANBus.  It's designed to be installed and used in electric vehicles.  You can stack a bunch of them in parallol in a rack/cabinet if you want more power than 60kW, but that one item will handle a 60kW DC-DC conversion all by itself.  Two of them will get you 120kW.  A fridge sized cabinet of those hooked in parallol would handle damn near a megawatt.  As to cooling, that unit requires ~5 L/min.  Two of them would be 10L (~2.5 gal)/min, which is the flow rate of a very small motorcycle engine (like <150cc).  A 600cc sportbike at cruising RPM will pump around 35-40 L/min.

Tesla's supercharger is a 12-pack of the same 10kW AC-DC converters that they use in their cars for AC charging stacked in a cabinet and paralloled to generate 120+kW.  Those units are also liquid-cooled.

You seem to be operating under the assumption that DC-DC converters must be the same size as AC-DC converters.

[GoCougs]

Um, no.  That is a fully functioning, stand-alone, self-contained 60 kW DC-DC converter along with necessary control circuitry to hook it up to a CANBus.  It's designed to be installed and used in electric vehicles.  You can stack a bunch of them in parallol in a rack/cabinet if you want more power than 60kW, but that one item will handle a 60kW DC-DC conversion all by itself.  Two of them will get you 120kW.  A fridge sized cabinet of those hooked in parallol would handle damn near a megawatt.  As to cooling, that unit requires ~5 L/min.  Two of them would be 10L (~2.5 gal)/min, which is the flow rate of a very small motorcycle engine (like <150cc).  A 600cc sportbike at cruising RPM will pump around 35-40 L/min.

Tesla's supercharger is a 12-pack of the same 10kW AC-DC converters that they use in their cars for AC charging stacked in a cabinet and paralloled to generate 120+kW.  Those units are also liquid-cooled.

You seem to be operating under the assumption that DC-DC converters must be the same size as AC-DC converters.

That is not standalone unit - it requires liquid cooling. Add in the cooling (heat exchanger, pump and plumbing) for two of them and you most certainly have a fridge size cabinet, or very close to it.

Those are used for things like boats and industrial equipment, and are at least $10,000 each, not including the cooling system. ANY sort of switching device at the kW rating - AC drive, transformer, power supply, etc. will be very expensive, prohibitively so for a retail passenger vehicle.

IMO you've chased this one way too far. A passenger EV will never have an on board 100 kW+ DC-to-DC converter on it. As demonstrated, vastly too big, heavy and expensive.

[MX793]

That is not standalone unit - it requires liquid cooling. Add in the cooling (heat exchanger, pump and plumbing) for two of them and you most certainly have a fridge size cabinet, or very close to it.

Those are used for things like boats and industrial equipment, and are at least $10,000 each, not including the cooling system. ANY sort of switching device at the kW rating - AC drive, transformer, power supply, etc. will be very expensive, prohibitively so for a retail passenger vehicle.

As I mentioned, the onboard, 10kW AC/DC unit that Tesla already uses, as well as the battery, already has liquid cooling.  The heat exchanger, pump, plumbing, etc is already there.  You also seem to overlook the fact that Tesla's drive motors, each running at 100s of kWs, are AC motors.  So somewhere in that car there's some DC/AC inversion handling power levels on the order of hundreds of kWs (~300kW per motor).  Additionally, since the car can also use regenerative braking, at up to ~60kW from what I can find, there's a substantial AC/DC conversion happening onboard between the motor and battery.  If 100 kW sized power conversion using switching devices requires a refrigerator sized rack of components, why isn't every Tesla saddled by some refrigerator sized tumor to house all of this power conversion gear (between upwards of ~600kW worth of DC/AC inversion plus existing onboard AC/DC conversion HW)?  A less expensive BMW i3 or Chevy Bolt require much of the same kit (both have 100+ kW AC motors).  So why aren't these vehicles prohibitively expensive and lugging around huge power racks with massive cooling systems to support it all?

IMO you've chased this one way too far. A passenger EV will never have an on board 100 kW+ DC-to-DC converter on it. As demonstrated, vastly too big, heavy and expensive.

You haven't demonstrate anything other than statements very much contradictory to reality.

[AutobahnSHO]

Are you forgetting cougs doesn't believe self-driving cars will ever happen???...

[MexicoCityM3]

IMO you've chased this one way too far. A passenger EV will never have an on board 100 kW+ DC-to-DC converter on it. As demonstrated, vastly too big, heavy and expensive.

"No computer will ever need more than 640KB of RAM"

I think you underestimate minaturization and future tech in general.

[GoCougs]

"No computer will ever need more than 640KB of RAM"

I think you underestimate minaturization and future tech in general.

A moderate portion of what I do for a career, and have been doing so for ~20+ years, is electric motors and the things that power them - inverters, power supplies, AC drives, servo drives, etc. So when I say a thing about the subject, it comes from there, not from Google.

The fundamental limitation is the transistor, and necessarily, the power transistor (heat). Not until the power transistor is replaced will there be "miniaturization" in this area (barring band aid solutions like liquid cooling or the like). A 120 kW power device - power supply, inverter, AC motor drive - is big, heavy and expensive. There is no argument to this. Adding such additional functionality to a retail EV is prohibitive and it will never happen (that is, along as power conversion is done by the transistor).

[GoCougs]

As I mentioned, the onboard, 10kW AC/DC unit that Tesla already uses, as well as the battery, already has liquid cooling.  The heat exchanger, pump, plumbing, etc is already there.  You also seem to overlook the fact that Tesla's drive motors, each running at 100s of kWs, are AC motors.  So somewhere in that car there's some DC/AC inversion handling power levels on the order of hundreds of kWs (~300kW per motor).  Additionally, since the car can also use regenerative braking, at up to ~60kW from what I can find, there's a substantial AC/DC conversion happening onboard between the motor and battery.  If 100 kW sized power conversion using switching devices requires a refrigerator sized rack of components, why isn't every Tesla saddled by some refrigerator sized tumor to house all of this power conversion gear (between upwards of ~600kW worth of DC/AC inversion plus existing onboard AC/DC conversion HW)?  A less expensive BMW i3 or Chevy Bolt require much of the same kit (both have 100+ kW AC motors).  So why aren't these vehicles prohibitively expensive and lugging around huge power racks with massive cooling systems to support it all?

You haven't demonstrate anything other than statements very much contradictory to reality.

That is actually a good question, and luckily, the answer is an easy one.

First, Google the size of an industrial 300 hp AC induction motor and industrial 300 hp AC drive. Now compare those to the Model S 300 hp AC induction motor and 300 hp AC drive...

See the difference? The industrial motor weighs at least 2,000 lbs whereas the Model S motor appears to weigh 100-150 lbs. The industrial drive is about half the size of a fridge (which in turn has to be put into an electrical enclosure with fuses, breakers, etc., that will be larger than a fridge) and the Model S AC drive appears to be about the size of a small microwave.

So what's the answer then? No, Tesla didn't invent anything new. The answer is duty cycle. Most industrial equipment is designed to operate at 100% duty cycle whereas EVs operate at very low duty cycle. As I'm sure we all know by know, at full gas the Tesla S goes into reduced power mode in just a matter of minutes - it can't do a full lap of the N-Ring even at full gas. Why? Because the motor, AC drive and batteries start to overheat.

Why this talk about duty cycle? Because charging is high duty cycle, maybe even 100%. This is why the Tesla supercharging station is, wait for it, about the size of fridge, which is about what you'll see when you Google the size of a 120 kW power supply or AC drive fully integrated.

What I demonstrate is 20+ years of industry experience with these types of components.

[MX793]

A moderate portion of what I do for a career, and have been doing so for ~20+ years, is electric motors and the things that power them - inverters, power supplies, AC drives, servo drives, etc. So when I say a thing about the subject, it comes from there, not from Google.

Your experience has been mostly in factory equipment (automated manufacturing and robots), no?  There's no real a need to miniaturize stationary power systems for factories and buildings.  Nobody cares if you need a space the size of a small shed to house transformers and converters in a 300,000 sq ft factory space.  That all of the power gear you've ever worked with is massive doesn't mean it has to be that large.

The fundamental limitation is the transistor, and necessarily, the power transistor (heat). Not until the power transistor is replaced will there be "miniaturization" in this area (barring band aid solutions like liquid cooling or the like). A 120 kW power device - power supply, inverter, AC motor drive - is big, heavy and expensive. There is no argument to this. Adding such additional functionality to a retail EV is prohibitive and it will never happen (that is, along as power conversion is done by the transistor).

Except EV's already have this capability on board.

The Bolt has a 150 kW output AC motor and a battery.  Somewhere between the two, there is an inverter capable of turning > 150kW of DC power into 150 kW of AC power.  The i3 has a 125 kW AC motor being driven by a battery.  Somewhere it has an inverter capable turning >125kW of DC to AC.  The Tesla has upwards of 580 kW of AC motor, so somewhere in that car is the hardware to invert >580 kW of DC to 580 kW of AC power.  According to you, all of these, and especially the Tesla, should have an outhouse-sized shed of power management gear onboard to make that possible.  And yet they don't.  Two of them are even affordable for the average American household.

As noted, running that much power, either in charging or discharging a battery, comes along with a lot of heat.  Not just in the converters, but the battery pack too.  Dumping high power DC power into a battery is going to get that battery hot.  The Bolt and the Tesla, at the least, have liquid cooled batteries.  Tesla runs coolant through its battery while charging, as well as through the onboard 11kW AC/DC supply when being charged on AC.  It will even run the air conditioning during charging to further cool the battery and onboard supply (if AC charging) if just liquid-to-air cooling from the radiator and electric fans alone isn't cutting it. 

It would really not be that difficult to package a pair of DC-DC supplies like the one I posted in any of the current crop of EVs to permit 100+ kW rapid charging from a known DC source.  Their combined weight would be no more than 100 lbs and their combined volume only 1.5 cu ft.  The liquid cooling is already there since the batteries on pretty much all of these vehicles need it (and in Tesla's case, the onboard AC/DC charging supply needs it too).  If need be, the vehicle's AirCon could be used to refrigerate the coolant (which Tesla also does during charging).