# Diesel-electric series hybrid dreaming



## Matej (Dec 4, 2015)

Hello gentlemen,
Being a fan of both mechanical diesels and EV's, which I know are ironically opposite in terms of their environmental image, lately I have been more and more fascinated with diesel-electric series hybrids.

However, I would not want to utilize a universal industrial generator installed in the trunk. I want to use one of the OEM diesel engines that is actually made to fit in the car. One of the neatest aspects would be that at first glance the car would appear stock under the hood. No one would suspect that it is powered by electric motors hidden in the transmission tunnel. Most likely dual Warp 9's if I can make room for them.

My preference would be to use a permanent magnet 'pancake' DC motor attached to the diesel engine. This would allow for more room to fit the traction motors.
What are some approximate specifications I should look for when choosing a permanent magnet motor? I assume the best choice would be a motor rated for high voltage, high current, and low rpm. The problem is that I am not having much luck finding such permanent magnet motors, especially in pancake form.

I am also unsure on what the optimal diesel engine choice would be. There are inline four, five, and six-cylinder engines available that will all fit like stock. All are available in NA and turbo variants. On one end of the spectrum is a 75hp NA 4-cylinder and on the other is a 200hp turbo six-cylinder, with the other motors anywhere in between. The smaller motors are lighter and get the best mileage when used for traction, although even the big ones can get over 40mpg.
The problem is that I am not sure whether 75hp would be more than I would ever need for the application, or if I should just go with the biggest motor for the future potential of turning the car into a beastly road-going locomotive.

Of course, the electrical side will play a very important role as well. Especially how the generated power is fed into the battery pack. The few custom hybrids that I saw converted the generator output into VAC and fed it into a standard EV charger which worked as a range extender.
I would prefer to keep the output as VDC, using something like an MPPT charge controller, which should allow for higher current to be fed into the pack. That is assuming that I can find a high voltage MPPT controller, or use a few of them in parallel.

Finally, if a setup like this could generate enough power, it could be a perfect application for experimenting with supercapacitors. But that is just daydreaming at this point.

Thank you for any input or ideas.


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## Matej (Dec 4, 2015)

Is there a rule of thumb for approximating what voltages and amps a specific motor can generate and at what rpm, simply by knowing its manufacturer specifications?

I am trying to decide what the best motor would be to use as the generator for a series hybrid vehicle. Presumably, motors from OEM EV's and hybrids would be the best candidates, as they are made for running at higher RPM's and are already used for regeneration purposes.

The motors I am considering are the Honda Civic/Insight IMA pancake motor, Leaf motor, Smart ForTwo Electric Drive, or one of the Azure Dynamics motors.

I would like a motor that generates 144-160V somewhere between 1000-3000rpm, and I would like to choose the motor that will provide the most amps while doing so.
For example, if the generator is powerful enough, I could disconnect the battery pack when on the highway and drive on generated power alone. That would be amazing, if possible.

So far I have learned that the Honda IMA motor generates 30V at 400rpm and 250V at 4000rpm, and can output 50-100A (not sure at what rpm). That is very impressive for its compact dimensions, although I would like more amps.

If anyone happens to have figures for the Leaf, Smart, Solectria, or any other compact commonly available EV and hybrid motors, I would really appreciate it.
Thank you.


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## Matej (Dec 4, 2015)

Which of the following would be a better method of connecting the generator motor to the batter pack?

*Option 1*
Connect the output from the rectifier to the charger. This would allow the diesel generator to act as a range extender, even when the vehicle is moving. The car would sound like a diesel when driving in 'range extender mode.' When the car is stopped, it would charge the battery pack at whatever current the charger can put out. Are there chargers that can accept both AC and DC input? 

*Option 2*
Figure out at what RPM the generator puts out the desired voltage. Then connect the rectifier directly to the battery pack. This method could not be used under load while the car is moving. When driving, the generator would be dead weight, although the car would be quiet like an EV. The output current directly from the generator would be a lot higher than from the charger, so it could be used for charging the battery quickly in emergency situations (assuming the pack can handle the input current). I could just pull over on the side of the road, maybe even get a decent bit of charge in at stop lights or in parking lots. Of course, this method should not be used to fully charge the battery. I would only use it to get the the battery charged to perhaps 90% of its properly charged voltage, and then top it off with the on-board charger at home or at a charging station.


Which method would you gentlemen recommend? Is Option 2 stupid and dangerous? Are there any other setups I should consider?
Thank you for any input.


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## akseminole (Jan 5, 2014)

Here is a build thread about M38 Mike's extended range electric Jeep.

http://www.diyelectriccar.com/forums/showthread.php?t=48794

http://www.mpicard.net/m38mike/electrowillys/juicebox/juicebox_pg01.html


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## dcb (Dec 5, 2009)

Matej said:


> Which of the following would be a better method of connecting the generator motor to the batter pack?


Option 3 is best, connect it to the drive wheels and make it parallel and not series.

It is bad enough having to constantly talk about ICE's on an ELECTRIC car forum, but if you must do so, at least don't choose the most wasteful arrangement you can conceive.


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## Matej (Dec 4, 2015)

dcb said:


> Option 3 is best, connect it to the drive wheels and make it parallel and not series.
> 
> It is bad enough having to constantly talk about ICE's on an ELECTRIC car forum, but if you must do so, at least don't choose the most wasteful arrangement you can conceive.


Sorry, did not mean to offend. 
And thank you for the links.

I do not want parallel, because I want to drive it primarily as an EV when the distance allows, with the potential to go on longer trips without range anxiety (and without having to haul a trailer behind me). Plus the transmission tunnel is not large enough to convert it to a parallel hybrid, especially since I plan to use dual motors. And I do not want a transmission in the car, because transmissions break and are a pain to fix/replace.

In fact, I am visualizing making the ICE system/generator easily removable from the trunk. The stripped down Smart diesel engine weighs under 50kg and I would run it mostly on used vegetable oil, so waste and pollution would still be significantly lower than the average car, and definitely much less than a store-bought generator.


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## dcb (Dec 5, 2009)

Matej said:


> And I do not want a transmission in the car, because transmissions break and are a pain to fix/replace.


transmissions are pretty frigging reliable. This bastard car sounds like a royal PITA though.



Matej said:


> I want to use one of the OEM diesel engines that is actually made to fit in the car. One of the neatest aspects would be that at first glance the car would appear stock under the hood.


...


Matej said:


> In fact, I am visualizing making the ICE system/generator easily removable from the trunk.


Dude, you are all over the place here, you don't even know what you want.




Matej said:


> it could be a perfect application for experimenting with supercapacitors.


Just stop, now you are completely in the weeds. Build an EV or don't.

If you have an actual problem to solve, i.e. range, I suggest you keep a beater 5 speed civic/prius/diesel rabbit/?? in the barn for when you need range. Even a second hand chevy volt is pretty much guaranteed to work better and cost less that anything you have described and even has a parallel mode, and a crapton of engineering, it takes a LOT to get an ice and a generator and a motor to play well together.

These are actually nightmares you are having, WAKE UP MATEJ!!


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## raphen (Jan 11, 2017)

*raphen*

I like the idea of running a diesel to keep the battery charged for extended range. You will get far more range efficiency with diesel than gas. 
Hybrids are a joke, prius advertises at 45+ when a turbo diesel VW gets 50+. A hybrid should be getting at least 60. If cars were designed to aerodynamic standards instead of market appeal we would be seeing mpg in the 80 range easy. The civic and crx have aerodynamic kits that will get up there. 
If airplanes were designed like cars, flights would cost tens of thousands of dollars per seat.


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## Jeremyfc1 (Feb 5, 2016)

Ok slow down a min. Take a step back and look at the problem. What are you trying to achieve? Azure dynamics partnered with ford and made a parallel hybrid in the transit and E450 shuttles. Using the 7.3? Or 6.0 diesel with a starter generator on an accessory drive belt. And a big ac motor behind the. Transmission before the rear end. It worked well just didn't have the dealer ships suport to work on it and ultimately it went under. I personally have three full hybrid drive systems out of said box trucks and am using them to convert to sole electric drive projects. If you want a hybrid I'd consider selling a complete unit with everything


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