There are several insurers over here that specialise in kit-car insurance, which is the main reason why I chose a Quantum over the standard Fiesta upon which it is based.  Yes, it's GRP bodyshell, which makes the car 20% bigger and 6% lighter, but the main advantage is that kit-car insurers are tolerant of wierd things under the bonnet.  Since my 70kW of motors produce about the same power as the petrol XR2 engine that is in there now, their only loading will be for the cost of the batteries.  But the batteries cost me less than £250, so that will be fine.

If I were to have a rush of capitalism to the head, and start making them, I'd be up against the 500-unit limit for SVA, which would curtail production a little.  But then I don't have the infrastructure to make or sell 1,000,000 cars. I suspect I could make and sell a couple of hundred a year here in Europe, and having them designated "kit cars" would help insurance a lot.  The only difference would be that I'd use all new parts and so get a new car registration mark.  My guess is that they'd retail for about £16,000 each with the lithiums in, which is more than the cheapest cars but much less than the more expensive ones.

More likely, if I had such a rush of capitalism to the head, I'd lie down until it went away.  But if I can get to these sorts of prices, handbuilding four cars a week in a workshop somewhere, so can Ford.

Before that will happen though there will have to be a revolution in storage technology first, or the creation of a hydrogen distribution network (as well as production on scales that are not even on the drawing board right now). The speed with which you fill up your gass tank with joules is pretty impressive when compared to charging a battery.

That it is.  I have never seen a practical battery technology that can refuel at faster than the 1C rate or for more than 80% of capacity.  So an EV needs to carry a day's fuel, or a backup generator for those few occasions we drive further.  But an alternative would be charging points in the car-parks of motorway service stations and roadside cafés, so you do 3 hours driving, then plug the car in while you have something to eat.  The infrastructure to refuel an EV is much simpler than that required to refuel an ICE, which makes it cheaper and more cost-effective to offer refuelling points.  I can buy outdoor mains plugs from B&Q for less than £5 each - you won't get a petrol pump for anything less than 1000 times that cost.  To cost the same for the fuelling equipment, your petrol pump needs to refuel the car to 80% in less than 3 seconds, which is more like F1 pit-stop speeds.

I still don't believe in the "hydrogen economy" for cars, because their refuelling infrastructure is even more expensive, but even they will need motors to turn the electrical energy from the fuel cells into mechanical energy to push the car down the road.

The revolution in storage technology is called "lithium": as well as the Thunder Sky units I keep mentioning, the last three months have seen announcements from several other battery manufacturers: Valence Technology, for example; or a French company called BatScap.  I'm expecting that by the time my lead-acid AGMs wear out, that I will be able to buy lithium batteries from lots of places.

Some people (for instance the writer of a book called 'hubert's peak' (sp?) claim that we are rapidly running out of time to make the shift. I don't know about that (he's got an awful lot of evidence to back it up though) but one thing is for sure, the way we burn fossiil fuel will end, the debate is about when, not if. Oil prices are skyrocketing and burning it in cars and powerplants is probably the worst possible use. The plastics industry needs it pretty badly and they do not have any viable alternatives (but the transportation industry does).

My oil-prospector brother also believes that time is running out, and we are already past the peak.  However, be of good cheer: plastics can be made from coal (and so can oil), and it seems certain they can be made from organic oils, too.  The price of plastics may go up, but they won't disappear.  More expensive plastics will encourage people to value plastic items, rather than throwing them away, as shown by the Irish "bag tax".

I think this is a modification Jerry did to add regenerative braking to his Zappi controlled motor. This is similar to what Otmar (maker of the Zilla motor controllers) did on an earlier EV with an older Curtis controller.

http://cafeelectric.com
http://cafeelectric.com/curtis/regen/index.html

Adding regen to a low side switching controller can get a bit messy when done with external contactors. But it can be done!

Probably something like this:-

http://www.jerryrig.com/convert/step38.html

"The car is propelled by electric motors at each of the wheels, eliminating the need for heavy components of a conventional car such as driveshaft, differential and transaxle. This shrinks the weight further, making it possible to supply that electricity from a relatively small bank of fuel cells -- which also helps keep costs down."

The spot where the engine used to be at the other sides of the half shafts is the place to go for instead of on the hubs (my bad). In most cars there used to be an ICE there, so you should have all the room you want !

I wonder how much margin there is in those motors, and how much it would take to put a thermal feedback in there that allows you to run the motor at its rated winding temperature instead of at it's rated current.

Sort of a controlled overload situation during accelleration. That might gain you some torque for free.

How about snow mobile like belt drives ? Or maybe planetary gears or inline reducers (like the kind they use in the process industry, only one wear part and no gears). There are tooth belts with that kind of torque (kevlar inlay, hardly any stretch, very little wear, extremely strong, up to 10's of HP are readily available).

A car would probably need to be seriously overdesigned wrt starting torque, imagine starting from a standstill going uphill with four people and some luggage in the car ! (think skiiing holiday or so)

fwiw, I spent some time in Poland before the wall fell, and lots of people there drove wartburgs, serenas and trabants. These are all very old 2 stroke eastblock cars, the engines in these things were unbelievably small, about 25 hp. Yet they did surprisingly well in traffic, no problem at all. The trabant was especially popular in east germany where it was produced. It has a plastic body (with a resin so flammable that you'd wonder if this was east germany's solution to the overpopulation problem) and weighed about 630 Kg.

Judging by the fact that that was a car that was probably living at the low end of 'possible' I'd say for practical use you may need to up your torque requirements a bit.

The easiest conversion then would be a lightweight four wheel drive car. That would give you four spots to tie motors to instead of two ?

In robotics when they use two motors that are not tied together, they often run a counter shaft so that both motors spin the same direction.

Using AC motors which would be inherently synchronous may be a solution, but even this presents its own problem. This is the problem of cornering, you no longer have a differential to allow the wheels to spin at different rates.

In my mind a single motor driving a differential is a good thing. The differential also gives you a gear reduction for increased torque. I would think a small vehicle with an aluminum transaxle solves a bunch of problems, not to mention having quite a gear selection to choose from.

My personal selection for an EV would be a small pick-up truck, rear wheel drive with the batteries under the bed. These little trucks already have the needed suspension components for the increased weight and they are relatively light weight.

If the motor was travelling quickly enough you'd be able to use the motor voltage without needing to up-convert it: but then you'd be travelling faster than the car was designed to go.  Since you want your batteries to be of a voltage in excess of the peak voltage produced at top speed, to get recharging you need those "buck" convertors to get the charging current to flow.