Of the links that MetroMPG posted, this one
Douglas Hartley's 1994 Skoda Favourit Elta Pickup seems to be closest to what I was thinking.
Any of the EMIS systems that I've seen posted all look to be rather expensive, while adding NO "electric only" range - just an electric boost at in town speeds. The two links showed the cost of adding the EMIS system as being $10,000 and $15,000 of cost added on top of the vehicle.
Also, the rear-wheel drive connection with a series-wound motor doesn't provide for regeneration. I think that for a plug-in hybrid, regen would be an important feature, not just for start and stop, but for cruise-charging as well.
Can somebody with a better understanding than me of various types of electric motors help me with something? In people that I have talked with so far, it seems to come up that a DC Series-Wound motor has enough torque to bolt it right to the rear differential of a car and drive it directly. DC motors are usually lower voltage than AC (so fewer batteries)
Apparently, AC motors don't produce as much torque, so you still need a transmission and be able to go through the gears to produce the torque to give you the required torque to accelerate.
Does that sound about right? How about a shunt-wound motor, or brushless DC?
It seems to me that a series hybrid is pretty straight forward - build an electric car (AC/DC, front-wheel/rear-wheel, doesn't really matter) and add an appropriate generator.
To do a parallel hybrid, it becomes more complicated, but also opens up more possibilities - does the electric motor go on the front or the back? Is the ICE front-wheel or rear-wheel drive? How to arrange for cruise charging?
Of vehicles that I already have access to....
I could just add a generator to the Electro-Metro. My experiments with the LP generator showed that it can work, but I didn't care for the noise, I didn't have an ideal place to mount the LP tank, and I never got that used generator to run as well as it was supposed to. The car would still be powered by a brushed DC motor. That means brush-wear over time, and no regenerative capabilities. But no regen is not a big deal when there's a generator in the trunk. It would be a BAD setup for big hills. I test drove a RAV-4 electric in skiing country in Pennsylvania. Without the regen on the AC motor in that vehicle, I would have been on the brakes the whole time going down those hills!
That wouldn't be too bad in my area, as there's not a whole lot that's super-steep, but if I wanted to drive-it across country (out to the Mother Earth News Fair at Seven Springs, PA, for example) it would be a problem.
I think a generator like
THIS would work (as long as I kept my speed reasonable.) I measured, and it would fit in the Metro. I'd still have to do a fair amount of sound-proofing, routing the exhaust, etc.
I also have a Chevy S10 pickup truck. It has a 2.2L gas engine and 5-speed manual transmission, 2-wheel real-wheel drive. I have an old diesel engine, naturally aspirated 2.4l from a Mercedes 240D. The plan for too long has been to put the diesel in the S10, to gain the fuel economy, possible use of bio-fuels, and other advantages that a diesel provides.
That's not an ideal setup for a hybrid, though. I could do an "EMIS-style" hybrid on it. I would be able to find a large DC series wound-forklift motor
at an affordable price. I think a friend of mine still has a 12" diameter one about. That motor could be run at 48V on up.
Since the transmission could get put in neutral, it would be very easy to run on just electric. (The EMIS system requires that the vehicle be automatic transmission and 1996 or newer to use throttle info from the OBDII.)
At that point though, the motor would be driving the differential AND spinning shaft going up to to tranny. Perhaps some sort of freewheel clutch could be used?
I still like the idea of a front-engine, front-wheel drive vehicle and adding a motor to the back end.
At this point, it seems like only a beefy series-wound motor would be the right thing to plop onto the rear axle. That wouldn't allow for regeneration. It would allow for a certain range on electric only, and firing up the ICE once the batteries are discharged. That would basically be a parallel version of the Volt (plus the potential advantage of four-wheel drive.)
Without use of non-fossil fuels, that's not much of an advantage over something a person could just run out and buy right now.
If it was a front-wheel drive hybrid, with a diesel engine (for fuel economy and ability to run on bio-diesel or veggie oil) it could be a vehicle to use ZERO fossil-fuels! Now that's starting to get into advantages over a Volt or Plug-in Prius!
What about regeneration though? It seems a shame to not be able to capture/recapture some of the energy from the ICE system. How about an alternator that runs a charger for the battery pack (or custom, high voltage output alternator) to load the engine a bit at cruising speed? Good idea, or starting to get too complicated?
Keep your thoughts and ideas coming!