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Discussion Starter #1
Hi All

Really new to all this so go gently please...

I have a 67 Beetle here in Torbay South Devon in the UK which I would like to convert to Electric (on a budget) for short trips with kids on sunny days all under 50 mph

Question: A few years back I was looking into a budget DC series wound forklift motor running at 72-96V'ish mated to the Beetle transmission, with DIY Open Revolt Cougar Controller (but now the wiki page links are all dead...)

Keep coming across these ads for meiden AC 300V (think ex Mitsubishi m-miev) motors (which originally used some form of small gearbox) , what are your thoughts on their suitability and specs etc?
The beetle has a low hp and only every revs to 3000 rpm about town, but would this higher hp @ 9300 rpm or 14000 rpm "capable" motor produce enough power / torque when limited to the 3000-4000 rpm range with some AC pwm controller?


Once again very new to this so go easy.....

many thanks for your thoughts and time

David
 

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I have a 67 Beetle here in Torbay South Devon in the UK which I would like to convert to Electric...

Keep coming across these ads for meiden AC 300V (think ex Mitsubishi m-miev) motors (which originally used some form of small gearbox) , what are your thoughts on their suitability and specs etc?
The beetle has a low hp and only every revs to 3000 rpm about town, but would this higher hp @ 9300 rpm or 14000 rpm "capable" motor produce enough power / torque when limited to the 3000-4000 rpm range with some AC pwm controller?

These seem to be the front and rear motors from the Outlander PHEV, rather than the i-MiEV; each Outlander motor is more powerful than the one i-MiEV motor.

The front motor is used on a transaxle (from GKN) which also mounts the engine, and generator, and includes gearing between components, a clutch to mechanically connect the engine to the output, and a differential. The rear motor is used on a typical EV transaxle which includes reduction gearing and a differential; the i-MiEV unit has the same design. The entire Outlander PHEV (or i-MiEV) rear drive unit (motor plus transaxle) could be used to drive a Beetle if it would fit (which seems unlikely), or either motor could be adapted to a VW transaxle. The Outlander's front transaxle would be pointless for an EV.

These motors are typical of modern 3-phase permanent magnet motors used in EVs. They can produce a constant torque (limited by current to a level determined by the controller and inverter) up to some transition speed (often around 3000 rpm), then constant power from that point up to nearly their maximum speed. There's no need to keep motor speed down to the VW engine speed; you can spin it faster by leaving the transmission in a lower gear, as long as you don't turn the transaxle input shaft too fast for reliability.

The specs from Second Life don't completely make sense to me: the 60 kW and 70 kW motors are similar, but one is listed at 42 kg and the other at 27 kg... one may be wrong. The 27 kg weight is hard to believe, so they're could be both at least 42 kg (for comparison, a Leaf motor weighs about 58 kg; motor + transaxle weighs about 180 lb or 82 kg), but perhaps the motor listed at 27 kg is actually lighter, producing less torque but at higher speed. The "60 kW" motor linked above is a Meiden Y61; the other 60 kW motor at Second Life is a Meiden S61, presumably from the front of a pre-2020 Outlander PHEV. The "70 kW" motor linked above is presumably from the front of a 2020 Outlander PHEV, and is likely also a Meiden S61. Since Meidensha doesn't sell these motors to individual consumers (only to vehicle manufacturers) official specifications are not available.

If using the VW transaxle, the Y61 rear motor (the 60 kW / 9300 RPM listing at Second Life) is probably more suitable for the shaft speed range acceptable to the transaxle.
 

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I realize that the above post may be a bit confusing when it gets to the various Outlander PHEV motors. While the motor manufacturer doesn't provide specs, Mitsubishi does...
2019 MITSUBISHI OUTLANDER PHEV SPECS
2020 MITSUBISHI OUTLANDER PHEV SPECS

These specs make it clear that:
  • the front motor is the S61, rated at 60 kW and 137 Nm
  • the rear motor is the Y61, rated at 60 kW and 195 Nm
Second Life claims higher power for the 2020 front motor, but Mitsubishi does not.

The front motor turns up to 50% faster than the rear motor (according to Second Life), but produces only 70% of the torque, so it makes sense that they can both produce the same power. Either one can produce much more torque than an original 1963 Beetle (87 Nm @2400 RPM), and can produce it from zero speed up to something faster than the peak torque speed of the Beetle engine, so...
  • if minimum weight is valuable and high performance is not needed, the smaller S61 front motor would be preferable; and,
  • if weight is not critical and higher performance is important, the larger Y61 rear motor would be preferable.
Why would Mitsubishi not just use the lighter higher-speed motor at the rear as well? It likely can't be cooled effectively enough to sustain full output power for very long, it may be less efficient.
 

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These specs make it clear that:
  • the front motor is the S61, rated at 60 kW and 137 Nm
  • the rear motor is the Y61, rated at 60 kW and 195 Nm
These combinations of power and torque suggest that
  • the front motor (S61) can probably produce 137 Nm from zero to about 4200 RPM, and
  • the rear motor (Y61) can probably produce 195 Nm from zero to about 2900 RPM
 

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Discussion Starter #5
Hi Brian

And first, thank you very much for your extremely detailed and informative posts, I confess that I will have re-read them later to better digest...

Interested if anyone has physical experience of any of these with a conversion?

David
 

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I know out of budget but I have been referring to this as a real rough guide for parts. I have a type 1 setup in my formula car.
 

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David,

The answer to your question, Brian's thesis summarized, is "yes, it will work" if you limit the RPM and adapt the motor to the VW transaxle.

You get the optional bonus of 50% more "pep" if you suitably spec your battery pack and decide to deliver rated current to the motor. Otherwise, that can be backed off by about a third to get what you had with the Bug motor.
 

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I know out of budget but I have been referring to this as a real rough guide for parts. I have a type 1 setup in my formula car.
Some people still build conversions with that technology, but it's all well out of date, and anyone who describes a WarP 9 as a 200 horsepower motor or calls a sheet of acrylic around the battery "bulletproof" shouldn't be taken too seriously. To be fair 200 hp may be realistic for the few seconds needed in the solo competition car, but a street Beetle is a very different situation.
 

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These combinations of power and torque suggest that
  • the front motor (S61) can probably produce 137 Nm from zero to about 4200 RPM, and
  • the front motor (Y61) can probably produce 195 Nm from zero to about 2900 RPM
The 70kW "motor" could be the front mounted "generator" used in the Outlander transaxle
120094
 

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Discussion Starter #10
From your supplied photo above and from the images supplied on their web pages, (if they properly show what they are selling,and not " general reference 'ish" photos) I think you may well be correct.

So should this not be listed for sale as a "motor"?

From my "limited" understanding an alternator can be "made" to work as a motor with some modifications, but should we stay away from the 70kw generator as it would involve extra work? or not?

many thanks

David
 

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It would probably work fine as a motor. As a generator, think of it as a motor in permanent regen mode. The oil cooling could be a problem. If the 70(if it is as I suspect) and 60kW motors(generators) mounted on the front transaxle are like other oil cooled motor/generators, they have oil directly sprayed onto the stator windings. The oil probably drains back into a sump in the transaxle, through holes in the motor mounting flange. This would explain the one(as far as I can tell) coolant tube on these motors. This could be a lot of work to set-up properly. The rear motor seems to have a relatively simple anti-freeze(probably not oil) in and out cooling jacket.
 

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Discussion Starter #12
It would probably work fine as a motor. As a generator, think of it as a motor in permanent regen mode. The oil cooling could be a problem. If the 70(if it is as I suspect) and 60kW motors(generators) mounted on the front transaxle are like other oil cooled motor/generators, they have oil directly sprayed onto the stator windings. The oil probably drains back into a sump in the transaxle, through holes in the motor mounting flange. This would explain the one(as far as I can tell) coolant tube on these motors. This could be a lot of work to set-up properly. The rear motor seems to have a relatively simple anti-freeze(probably not oil) in and out cooling jacket.
Thanks for your thoughts, plus the extra info about how the "oil cooling" differs from water cooling... these things are highly appreciated and help educate those of us less knowledgeable from making expensive mistakes!

Important "nuggets of information" which you take for granted like these, need to be jointly compiled (by those in the know) into a stickies for "all newbies" to be able to grasp.

Once again thanks to everyone's time and efforts.

David
 

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The 70kW "motor" could be the front mounted "generator" used in the Outlander transaxle View attachment 120094
It could be... the generator is likely similar to the motors and should be suitable for higher continuous power than the front motor. And visually it looks like a match - good spotting. :)

From your supplied photo above and from the images supplied on their web pages, (if they properly show what they are selling,and not " general reference 'ish" photos) I think you may well be correct.

So should this not be listed for sale as a "motor"?

From my "limited" understanding an alternator can be "made" to work as a motor with some modifications, but should we stay away from the 70kw generator as it would involve extra work? or not?
Yes, the photo of the unit listed by Second Life as 70KW EV MOTOR | 14000RPM matches nicely. I assume that Second Life's photos are of the actual units they have... if only because that would be the easiest thing for them to do, and their other information seems to be generally based on measurements of the actual unit rather than by reference to published specifications.

Second Life is selling these as motors, and I don't see a problem with that. For a permanent magnet 3-phase machine, the assignment of "motor" or "generator" describes the way it used, not the machine itself; no modification is required. In some hybrids (such as the Toyota Hybrid Synergy Drive), they're called "motor-generator", because they serve both roles routinely in operation. Even this one - assuming it is the Outlander PHEV "generator" - is used primarily as the generator for series hybrid operation, but presumably also as the starter motor for the engine, and it could even be used as a motor for a high-power burst in parallel hybrid mode if the battery could handle that.

I don't see any problem with the 70 kW unit as a motor, but as is often the case, the real challenge may be with the controller/inverter. Since these motors have not been characterized to determine the parameters appropriate for an aftermarket inverter, it may be easiest to use them with the stock (in the Outlander PHEV) inverters... and the programming of the controller included with that inverter may not be intended to operate it as a motor.
 

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An updated summary of the Outlander PHEV motor/generators, as listed by Second Life with some specs from Mitsubishi:
  • generator
    • similar to Meiden S61
    • maximum speed 14,000 RPM
    • oil cooled
    • can probably produce 160 Nm from zero to about 4200 RPM, or 137 Nm from zero to about 4900 RPM, or some combination between those combinations
    • Second Life: 70KW EV MOTOR | 14000RPM
  • front motor
    • Meiden S61
    • maximum speed 14,000 RPM
    • oil cooled
    • can probably produce 137 Nm from zero to about 4200 RPM
    • Second Life: 60KW EV MOTOR | 14000RPM
  • rear motor
    • Meiden Y61
    • maximum speed 9,300 RPM
    • water cooled
    • can probably produce 195 Nm from zero to about 2900 RPM
    • Second Life: 60KW EV MOTOR | 9300RPM
 

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Neewb question why quote a max 14000 rpm but, "can probably produce 160 Nm from zero to about 4200 RPM, or 137 Nm from zero to about 4900 RPM, or some combination between those combinations" if the motor only really produces power to maybe 5000 rpm??
 

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Neewb question why quote a max 14000 rpm but, "can probably produce 160 Nm from zero to about 4200 RPM, or 137 Nm from zero to about 4900 RPM, or some combination between those combinations" if the motor only really produces power to maybe 5000 rpm??
I didn't say that "the motor only really produces power to maybe 5000 rpm". That would be like saying that any engine only really produces power to just above the peak torque speed.

The combination of fundamental motor characteristics and typical practices in controller/inverter design and programming mean that typical modern EV motors have a constant torque limit at low speed, corresponding to a current limit. The torque values quoted here for zero to whatever correspond to that current limit and resulting torque.
As motor speed increases, eventually that torque multiplied by motor speed equals the rated power output of the motor; that's the 4200 to 4900 RPM in this example. That's a transition speed.

In case this doesn't immediately make sense, note that mechanical power is the product of shaft speed and torque (literally multiply speed and torque in consistent units, and get power in the same system of units).

Above that transition speed, motor power is held constant (to limit battery power draw, or inverter heat handling capacity, or motor heat handling capacity, or whatever). That means that as speed increases torque decreases, but this isn't bad - it's ideal. :) It means that you can run the motor at essentially any speed you want, and the same power (the motor's full rated power) is available; for this Meiden motor that's the entire range from 4900 RPM or less to close to 14,000 RPM. This is why EV's don't usually have multiple transmission ratios - they don't need them.

The normal gearing design approach for an EV is to choose the ratio of motor to axle speed so that the motor is running at its maximum speed (14,000 RPM in this case) when the vehicle is driving at the maximum speed allowed (commonly about 150 km/h or 90 MPH for an ordinary car). Then full power is available from maximum speed all the way down to about one-third of that (50 km/h or 30 MPH). Below that low speed available power is limited by the torque limit, but that's usually all that the vehicle needs, anyway, as it is traction-limited.
 

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Considering this possibility...
The rear motor is used on a typical EV transaxle which includes reduction gearing and a differential; the i-MiEV unit has the same design. The entire Outlander PHEV (or i-MiEV) rear drive unit (motor plus transaxle) could be used to drive a Beetle if it would fit...
A member here is currently building a conversion using the Outlander rear unit:
Mini Marcos EV Conversion
This might be interesting to anyone considering this motor, even in a vehicle other than a Mini.

While the motor manufacturer doesn't provide specs, Mitsubishi does...
2019 MITSUBISHI OUTLANDER PHEV SPECS
2020 MITSUBISHI OUTLANDER PHEV SPECS

These specs make it clear that:
  • the front motor is the S61, rated at 60 kW and 137 Nm
  • the rear motor is the Y61, rated at 60 kW and 195 Nm
These combinations of power and torque suggest that
  • ...
  • the rear motor (Y61) can probably produce 195 Nm from zero to about 2900 RPM
If the motor is turning at 2900 RPM, and if the transaxle gear ratio is 6:1 (just a guess for the Outlander rear unit, I can't find the spec) then the axles would turn at 483 RPM or 29,000 revolutions per hour. With tires of the same overall diameter (25.4" or 645 mm) as the stock 1967 Beetle tires (165SR15 ), that corresponds to a road speed of 59 km/h (37 mph). So
  • At any speed from a standstill up to about 60 km/h the same torque would available, of about 1,200 Nm (885 lb-ft) - just 195 Nm multiplied by the gear ratio of 6:1. That corresponds to 3600 newtons (810 lb), enough to initially accelerate a tonne (1000 kg or 2200 pounds) of converted Beetle and driver at 3.6 m/s2, which is pretty good.
  • From about 60 km/h up, a constant 60 kW would be available, which is more than a stock Beetle has at any speed even if the speed and gear combination puts the engine at its optimal power point.
  • The maximum motor speed of 9300 RPM would correspond to about 190 km/h, but the car wouldn't be able to reach that speed with 60 kW.
  • If the reduction ratio is higher (and it likely is) the maximum speed would be lower but performance would be better.
 

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Discussion Starter #18
Thanks for the follow ups / extra info and link to Mini Marcos EV Conversion using the i-miev setup including him hoping to (modify the stock controller/inverter).
Wonder how he is getting on with this project and ability to hack the stock Mitsubishi electronics in particular...
 

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I noticed an interesting set of specs in a Mitsubishi web page:
Electric Motor Details
Front Motor
Rated Output kW (PS)25 (35)
Maximum Output kW (PS)60 (82)
Maximum Torque Nm (lb.ft)137 (101)
Rear Motor
Rated Output kW (PS)30 (41)
Maximum Output kW (PS)70 (95)
Maximum Torque Nm (lb.ft)195 (144)

The peak torque and power values are the same, but this is the first that I have seen of lower continuous power ratings.
 
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