Depends on the range you want. I would gues sthat teh totalpower train on a conventional vehicle including fuel is around about 70% of the unladen total.
After all, a car is just a power train plus some wheels plus a box to hold it all together. The box is conventinally made of rather cheap poor material - pressed steel, as there is a larger pressure on cost, than weight, in most cars. t one extree, yo can see smething like a carbon F1 car, whose bodyshell is almost nothing by comparison to the powertrain and driver. So you can in principle optimise your capital/running cost at almost any ratio.
Typ[ically one would add perhaps another 50% to that for load carryng, so powertrain to total laden weight would be roughly 50%.
Do that with lithiums, and you get to around 150-200 miles range more or less.
Well apart from the fact that because of precisely that one expects electric car uptake to be more on the urban/commuting front that fast motorway cruiser..every little help. Better aero can improve high speed economy, as can trading cornering performance on fat squishy tyres, for lower rolling resistance on taller harder tyres.
I am not supping at dribbles font. Far from it. Dribble is the worst advert for electric cars here. Iv'e done a lot of calculations on the feasibility, and the answer is, its feasible to produce an electric car that is more than good enough to be everyones 'second car' at least. I.e. the one that takes the kids to school, the person to work, does the shopping etc etc.
It wont do a 400 mile trip that well, that's for sure. Not without at least a 45 minute break somewhere in the middle, but for that, pay the price of a fuel car, take the breaks, or hire one for the purpose.
The single most important step is going from lead or nickle at sort of
30-50 mile ranges, to lithium that will net sort of 150 mile ranges, or a bit more if you shave away at some of the details to squeeze a bit more efficiency out.That takes the potential target journey from the sort of sub 10% to the > 90% mark.
Which I am not doing.
Lithium batteries are at around the 700MJ/tonne mark now. The very best Nickle metal hydride are less than half that.
I estimate a small car like a Punto needs arond a 50Kwh (180MJ) 'tank'. In NiMh that's 3/4 ton, with Li-Ion its more like 1/4 ton.
A liter of diesel is about 10Kwh..burned at say 20% efficiency in a good engine, 50 liters of diesel represents 100 KWh of battery.
So getting say 25 litres of diesel equivalent in a power train at around the 400kg mark is very doable with Li-Ion of one sort or another.
And getting 50 litres of diesel equivalent takes us up to around a half tonne of battery. That's very comparable with the weight of a normal IC power train..the electric motors dont add much, and there is very little else required like radioator, massive gearboxes or exhaust systems, or indeed even antivibration mounts and the mases of pipes and ducts that surround a typical IC installation.
The Prius is crap because it does none of that. It still has a conventional engine: All the electrical side is, is a slightly more efficient way to deploy it under certain road conditions.