My dream, and I have had this thought for years, is to place a small gas engine, not unlike a motorhome generator, in the trunk of an electric car.  the engine runs at a constant rpm when the switch is thrown by the batteries being too low.  It would not be enough to fully run the motor at highway speeds....but, it would charge the bats while stopped at a light, a drive-thru, or parked at work.  This is the way diesel/electric trains have worked for years...not my original idea.

The hybrids available today to me are a joke.  Too expensive and the mileage is worse than we have achieved 20 years ago, and the bats have to be replaced after 3 years or so at about $3,000 plus.  The ONLY good thing about the hybrids is the regenerative braking system, this is very useful to recapture some of the energy that we used to accelerate while stopping.

Think about a small gas motor running a generator on demand in the trunk.  suddenly, the range for your electric vehicle goes from 75 miles to well over 300.  Yes you might have to fill up the 5 gallon tank every so often but....this is my dream.  Any others???

Bill

thanx for the replys...so the eletric engine can be smaller then..great news about 50 to 60 ph eletric then!?
i was looking at the link that h20mojo had on his post..and there they used a starter engine from a airplane...where can i find that kind of a moter (or any good motor)?

and i was thinking about the lawnmover motor...is there any small fuel efficient motor? diesel perhaps? or a wankelmotor (less wearing?) a lawnmower i think is NOT designed to be economic?

just a perhaps stupid question!? the transmission. will the car just run on the eletric motor without the transmission? just bolt the engine to the PROPSHAFT?
in the link they still used the transmission

i wish that i could build this kind of car...

Since the torque of the electric motor is constant from 0-max. rpm, no transmission is required.  I have seen some conversions where they leave the transmission in but, I believe that this was done because it was easier to use the transaxle assembly than it would have been to design from scratch another way to get the power to the axles.  Myself, I would not use the trans, even more weight gone and that helps quite a bit.  Just my thoughts from what I have read.

Bill

okey..so how can i figure out the speed of the car then? is that determined from the rpm? so it wont top about 60km/h or anything..here in sweden we have 120km/h at the highway

I was thinking about that today while driving around.  I think I would remove everything and mount two bearings that would align with the axles and create a shaft to connect them.  May have to have some clutch device to compensate for the different speeds of the wheels while turning.  From this shaft, you can mount the motor and drive the shaft with a wide ribbed belt on a grooved pulley like a timing belt set up.  I guess you would have to calculate the ratio for the desired speed base on the rpm of the motor used.  Or, I guess one could mount two motors, smaller ones, for each of the drive axles in a direct drive configuration.  Then you would have to calculate the diameter of the tire and the rpm of the motor to see what speed you would get.

I have not tried any of this.  I am sure there are many people who have done conversions and would either sell you the plans/or parts required. With some research, I think one could figure it out on their own though.  To me, if someone else, or a bunch of people, have already done the experimentation, there is no sense in rediscovering what they have found.  It should not be that hard which is why I am so very not impressed with the hybrids offered by the big car makers.  Not a giant leap forward in my opinon, but several steps back.

Bill