# DIY Hybrid



## GarryA (Apr 17, 2011)

Not really DIY because the car is factory (Toyota Corolla), just the electric motor would be a new insert.
I have two, maybe three different scenarios:

First: A not quite fully powered EV motor but one of substantial torgue to push the car at good speed on a flat surface. It would be installed in the trunk and the EV batteries would be attached to the car alternator to keep it charged for prolonged distance. The batteries would not have to power any electrical in the car other than the electric motor.
Question: Would my car alternator be sufficient or would it burn out quickly?

Second: A full 35 - 40 hp DC Wound Motor in the trunk with a small (200cc - 500cc) engine in the front to power the alternator for the car battery to power the immediate car utilities, but also to charge the the electric motor batteries which again would just run the motor.
Question: Again, would the car alternator be sufficient or should I upgrade?
What would be a sufficient size engine to run the alternator?
Briggs and Stratton, small motorcycle, 1000cc, 5 hp?
Remember, I am attempting to increase range without having to plug it in.

I am seeking a balance between the least amount of fuel needed to run the alternator to charge both the car battery and the electric motor battery for the greatest range, best battery longevity and cheapest running capacity.

Prior, I had been on this forum for a smaller project but it was shelved for this "upgrade" from a two seater trike to my already existent car. I still have the plans for the trike but until I can find success in my other realms of earthly passage (job) I have to be more practical.


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## bjfreeman (Dec 7, 2011)

GarryA said:


> Not really DIY because the car is factory (Toyota Corolla), just the electric motor would be a new insert.
> I have two, maybe three different scenarios:
> 
> First: A not quite fully powered EV motor but one of substantial torgue to push the car at good speed on a flat surface. It would be installed in the trunk and the EV batteries would be attached to the car alternator to keep it charged for prolonged distance. The batteries would not have to power any electrical in the car other than the electric motor.
> Question: Would my car alternator be sufficient or would it burn out quickly?


Clarification. is the ICE going to remain hooked to the power train? how are you connecting the electric motor to the power train?

Answer: if the alternator can produce the above 30.6 KW at the Battery pack voltage, it will be fine. However i don't think you will find one at the Battery Pack voltage. The biggest i have seen is a 300 amp 24v gear driven alternator for Buses.
if you hooked a generator that would produce the KW and voltage, it will take the power from the engine so you will have less gas mileage.


> Second: A full 35 - 40 hp DC Wound Motor in the trunk with a small (200cc - 500cc) engine in the front to power the alternator for the car battery to power the immediate car utilities, but also to charge the the electric motor batteries which again would just run the motor.
> Question: Again, would the car alternator be sufficient or should I upgrade?
> What would be a sufficient size engine to run the alternator?
> Briggs and Stratton, small motorcycle, 1000cc, 5 hp?
> Remember, I am attempting to increase range without having to plug it in.


40HP= 30.6 KW. I have a 15hp for a 7KW generator.
so you would need a generator off the ICE that delivers as much.


> I am seeking a balance between the least amount of fuel needed to run the alternator to charge both the car battery and the electric motor battery for the greatest range, best battery longevity and cheapest running capacity.
> 
> Prior, I had been on this forum for a smaller project but it was shelved for this "upgrade" from a two seater trike to my already existent car. I still have the plans for the trike but until I can find success in my other realms of earthly passage (job) I have to be more practical.


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## GarryA (Apr 17, 2011)

bjfreeman said:


> Clarification. is the ICE going to remain hooked to the power train? how are you connecting the electric motor to the power train?
> 
> Answer: if the alternator can produce the above 30.6 KW at the Battery pack voltage, it will be fine. However i don't think you will find one at the Battery Pack voltage. The biggest i have seen is a 300 amp 24v gear driven alternator for Buses.
> if you hooked a generator that would produce the KW and voltage, it will take the power from the engine so you will have less gas mileage.
> ...




Ok, makes me think, but not deterred.


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## GarryA (Apr 17, 2011)

bjfreeman said:


> Clarification. is the ICE going to remain hooked to the power train? how are you connecting the electric motor to the power train?
> 
> Answer: if the alternator can produce the above 30.6 KW at the Battery pack voltage, it will be fine. However i don't think you will find one at the Battery Pack voltage. The biggest i have seen is a 300 amp 24v gear driven alternator for Buses.
> if you hooked a generator that would produce the KW and voltage, it will take the power from the engine so you will have less gas mileage.
> ...




Ok, makes me think, but not deterred.

How fast of a charge to the "ICE" batteries are you predicting?
If I can run it for 8 hours before charging at a wall outlet at say, twice the amperage of a wall plug that takes 8 hours to charge...............?


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## ga2500ev (Apr 20, 2008)

GarryA said:


> Not really DIY because the car is factory (Toyota Corolla), just the electric motor would be a new insert.
> I have two, maybe three different scenarios:
> 
> First: A not quite fully powered EV motor but one of substantial torgue to push the car at good speed on a flat surface. It would be installed in the trunk and the EV batteries would be attached to the car alternator to keep it charged for prolonged distance. The batteries would not have to power any electrical in the car other than the electric motor.
> ...


While your project is an interesting idea, it is unlikely that it will ever see any usable payback. Let me see if I can give you a better idea of how hybrids work.

The reason gas engines have relatively poor conversion efficiency is because they rarely run in their ideal power band. In order to generate sufficient torque, ICE generally are specified to be way overpowered in order to generate decent acceleration at all speeds.

What hybrids of all types attempt to do is to get the gas engine to always run in its ideal power band where it generates sufficient average power to drive the car without having to ever generate the peak power that the car needs to maneuver properly. Whether this is Toyota's Synergy drive, which uses a complex planetary gear set to mix and transfer power between the gas engine, electric motor, batteries, and the wheels, or a series hybrid like the Volt where the gas engine only powers the batteries and electric motor and never the wheels directly, the objective is to always run the gas engine at maximum efficiency as necessary and let the much more efficient battery/electric motor setup handle all the peak power issues of normal usage. All of this is usually captured under the name "Atkinson cycle engine".

For the most part retrofitting an existing ICE setup with an electric motor gains little of the benefit because the ICE is still a peak power engine. Small gains can be had using the electric engine as a power assist and possibly getting back from regenerative braking energy. But the true leverage of using a smaller engine with average power to drive an electric drivetrain handling peak power is lost.

So if you really wanted to pull this off, the first thing you'd need to do is pull the existing ICE for the Corolla. Replace it with an electric drivetrain and batteries, essentially converting the car to a pure electric. Then install a much smaller ICE with sufficient average power to drive that drivetrain. Think along the lines of a 3 cylinder 1.0L Geo metro engine. Tune that engine to run at optimum efficiency at a single RPM speed and use it to drive an alternator/genset setup that can charge the batteries and move the Corolla at average power.

Then and only then would there be a hybrid worth doing. And a BTW, it makes little sense to install a battery setup into a vehicle and not have a port for plug in charging. Electricity from the wall is both cheaper and more efficient than any other type of charging. 

Just my 2 cents... Hope it helps.

ga2500ev


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## major (Apr 4, 2008)

It is my understanding that the Volt is not a series hybrid and does have a mechanical path from the engine to the wheels. And here is a neat vid of the Atkinson cycle. http://www.roadandtrack.com/auto-news/tech/video-the-real-atkinson-cycle


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## bjfreeman (Dec 7, 2011)

GarryA said:


> Ok, makes me think, but not deterred.
> 
> How fast of a charge to the "ICE" batteries are you predicting?
> If I can run it for 8 hours before charging at a wall outlet at say, twice the amperage of a wall plug that takes 8 hours to charge...............?


Internal Combustion Engine (ICE). 
if you look at the Via you can see what they are doing along the same lines.
Now if you look at the EP50 hybrid transmission, you have a different setup. here the ICE(190HP) is used for continuous power and the Electric (300KW) is used for starts and assists for HP.

the problem with most passenger vehicles is there is not room to mount a Generator on the back of the ICE because the Transmission connect directly to the ICE. So to use your way would require removing the transmission.


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## Overlander23 (Jun 15, 2009)

The Volt can have an mechanical connection to the wheels. I think basically, there are two motor/generators (one large and one small) and two clutches. The two motors are in series with each other and the ICE, while two clutches sit between the components; ICE, clutch, small motor, clutch, large motor, wheels. The large motor is always connected to the wheels, while the small motor and ICE can be dropped in and out of the system via the clutches.

When in EV mode, all clutches are disengaged and the large motor is used for traction and to recharge the battery pack in traction regen situations.

In range extended mode, the clutch between the engine and small motor is engaged. The small motor generates power that goes to the battery pack. The large motor is still disengaged from the small motor (and thus the engine) and is powered from the battery pack. This is most like a pure series hybrid.

At high speeds (70+ mph) or under high loads in EV-mode, the clutch between the large motor and small motor engages allowing both electric motors to power the vehicle. The ICE remains disengaged.

At high speeds (70+ mph) in range extended mode, the clutches between the large motor, small motor, and ICE engage and the ICE participates charging both the battery pack and sending torque to the wheels.

So the ICE can directly power the wheels... however, unlike the Prius the ICE only ever helps the electric motors. The ICE is not used by itself. It's merely support for the motors. In contrast, the Prius usually operates with the motor as the support player to the ICE.


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## ga2500ev (Apr 20, 2008)

In regards to the Volt: I am enlightened...

ga2500ev


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## bjfreeman (Dec 7, 2011)

* Chevrolet Volt Powertrain*

Prius powertrain


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## Salty9 (Jul 13, 2009)

major said:


> It is my understanding that the Volt is not a series hybrid and does have a mechanical path from the engine to the wheels. And here is a neat vid of the Atkinson cycle. http://www.roadandtrack.com/auto-news/tech/video-the-real-atkinson-cycle


Thanks, Major.

Interesting. Lot of thrashing around going on there. I wouldn't trust it for longevity.


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