# how good Prius MG2 ? Leaf ?



## chentron (Nov 13, 2017)

I plan to make my first conversion. Car donor will be a suzuki SJ410.
After two weeks reading I am not still decided which motor choice.
alibaba full of chinese motor, some with good specifications on paper, but not sure and confident of reliability in chinese products.
One of my options is take the motor from a Prius or a Leaf.
One forum user is doing the conversion but it look now he is with problems: 
http://www.diyelectriccar.com/forums/showthread.php?t=186585

Also I am not sure to understand the resolver/encoder thing.
But principal problem is Leaf is not a common car in my country, Spain, so It is hard to get the motor.

So the principal option is the Prius MG2,very common. I have seen it is a sinchronous permaneng magnets that need 500VAC, so battery might be about 707 volts (500x1,414). I think this will not be the problem if I use Paul controller. 
I also see cooling water, but is very limited to only a fraction of the carcase. I am not sure if this will be a problem.
So I am amazed that nobody take this motor for doing an EV(I did not find anybody). 
So what I am missing ? Am I a wrong with this motor ? Could i rescue also IGBT or inverter ?
Actually my alternatives are the siemens 1pv35... (very powerful but expensive) and I see last days an AC24LS very cheap but may be enough for my needs, no more than 100 kmh and no more of 60 km/day, 
thanks for your opinion.


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## Kevin Sharpe (Jul 4, 2011)

chentron said:


> But principal problem is Leaf is not a common car in my country, Spain, so It is hard to get the motor.


The Leaf drivetrain is widely available from wrecks in the EU and I have a friend who recently purchased one for 600 USD. If Spain is difficult try looking at breakers in The Netherlands.

Here is an excellent thread that details various projects that have used the Leaf drivetrain.


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## brian_ (Feb 7, 2017)

*Prius MG2*



chentron said:


> So the principal option is the Prius MG2,very common. I have seen it is a sinchronous permaneng magnets that need 500VAC, so battery might be about 707 volts (500x1,414).


Toyota does not use a 700-volt battery; they use a battery at about half that voltage, and double the voltage in the inverter.



chentron said:


> I also see cooling water, but is very limited to only a fraction of the carcase. I am not sure if this will be a problem.


Do you mean it might not be a problem to run it without cooling? Essentially the same motor is used as MGR - the rear axle drive motor in AWD hybrids such as the Highlander and RAV4 - without circulating coolant... but in that configuration it can only handle significant power for a short time before getting too hot.



chentron said:


> So I am amazed that nobody take this motor for doing an EV(I did not find anybody).
> So what I am missing ? Am I a wrong with this motor ? Could i rescue also IGBT or inverter ?


The first problem is that the motor doesn't come with a convenient housing, and most do-it-yourself builders are not up to the task of building a housing.

I have heard of people using the whole Prius transaxle, including both motors and reduction gearing and differential, without the engine. This requires locking out the engine input shaft (if you want to use MG1), and convincing the controls to run in EV mode all of the time.

The obvious solution to inverter compatibility with the motor and its encoder is to use the original inverter; however, this also brings the challenge of controlling the inverter without the rest of the car's original systems.


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## chentron (Nov 13, 2017)

*Re: Prius MG2*

To be rigorous, prius first series are 202 volts.
About cooling, sorry my bad english, I mean that may be MG2 is designed to only run for a few minutes and limited to 50 km/h , so the cooling is limited to only a fraction of the carcase. What could happen if this engine run for 1 hour at 100 km/h ? 
The speed limit is also the reason to avoid the original electronics. 
Could be still used the IGBT or inverter ? I dont know.

I have seen disasembling electric motor. MG2 can stay inside it carcase, without MG1, planetary sprockets and all the associated hardware, only with a shaft. 

https://www.youtube.com/watch?v=Eg8c2_eS-do

so I think it might be possible to run this engine alone, without any of the OEM electronics. The mistery to me is how the encoder works. 
Experienced people ... do you see more problems ?







brian_ said:


> Toyota does not use a 700-volt battery; they use a battery at about half that voltage, and double the voltage in the inverter.
> 
> 
> 
> ...


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## brian_ (Feb 7, 2017)

chentron said:


> About cooling, sorry my bad english, I mean that may be MG2 is designed to only run for a few minutes and limited to 50 km/h , so the cooling is limited to only a fraction of the carcase. What could happen if this engine run for 1 hour at 100 km/h ?


In this hybrid system, the engine cannot drive the vehicle without using MG1, either generating or driving depending on road speed and engine speed. To bring the net electrical power flow back to zero, MG2 runs as a motor (if MG1 is generating) or generator (if MG1 is driving). That means that MG2 runs continuously, not just for a few minutes at a time.

The vehicle may be limited in EV mode to 50 km/h and for a limited time, but I don't know if that is a limitation of MG2 cooling; limited battery capacity and cooling seem much more likely.


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## brian_ (Feb 7, 2017)

chentron said:


> I have seen disasembling electric motor. MG2 can stay inside it carcase, without MG1, planetary sprockets and all the associated hardware, only with a shaft.
> 
> https://www.youtube.com/watch?v=Eg8c2_eS-do
> 
> so I think it might be possible to run this engine alone, without any of the OEM electronics.


The video shows that the transaxle has two major housing parts, and that MG2 is contained in the part which is further from the engine. You could use just that part of the transaxle case, but it is not designed to be used without the other part: the two parts meet to form the housing for the power combiner (planetary gear set), chain drive, reduction gear, oil pump, and differential. With just the MG2 in its end of the case, the case wouldn't even hold oil and wouldn't have an oil pump.

The Prius transaxle changed in design and I assume that this is an earlier one; the later version shifts the position of MG2, but I can only guess that it has the same issues if trying to use MG2 by itself.

This is why there has been some interest in using the MGR assembly, complete with its reduction gearing and differential, despite the lack of cooling.

It could certainly be run without the OEM electronics, regardless of case considerations.


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