tony sayer wrote:
In article , Doctor Drivel invalid@not-
for-mail.invalid scribeth thus

"The Other Mike" wrote in message
...
On Tue, 16 Oct 2012 00:14:26 +0100, "Doctor Drivel"
wrote:

SteveW wrote:

Pure electric vehicles
cannot (may never?) have the energy density and rapid refill
times of the "old" technology.

That is pure nonsense.


Petrol is around 34MJ per litre. A 50 litre refuel takes around 2
minutes

So that is 1700MJ transferred in 2 minutes

1MJ = 0.28 kWh

Or around 476kWh of energy transferred from the petrol station
storage tank to
the car fuel tank in 2 minutes

But 80% of the energy in that tank is wasted. So go back and do
some sums.

Why don't you give us some realistic realisable sums instead?..

I am not the one doing the skewed sums. The average vehicle wastes 80% of
the energy in the tank, negating any energy density claims of the fuel in
running vehicles. The average electric car wastes less than 5% of the stored
energy. There is the clue.

Then take into account advances in batteries (Toshiba) and supercapacitors,
etc and the IC engines as direct power units become unfeasible. They will be
relegated to occassional use as range extednersa dn designed specifically as
such. Mazda are bringing out a Small rotary range extedner next year,
running at its constant speed sweet spot. Lotus are having a 3 cyl small &
light 1100cc range extending genny unit made.

BMW's have a charging system that only charges when the engine is on
over-run or braking. The alternator is disconnected via a beefy clutch when
the engine is powering the car. The same idea could be applied to an a/c
compressor, and when running around a town/city the mpg must clearly rise as
the a/c, like the alternator, only runs when on engine over-run or braking.
Of course an override switch for the a/c must be on the dash. Fuel
consumption must rise substantially implementing these two simple measurers.

In city driving BMW viewed the kinetic energy would be enough to charge the
battery. A long highway drive would entail the alternator coming in
occasionally - not all the time. BMW said about 4% better fuel economy from
the alternator alone.

To make matters better put in electric power steering and fuel consumption
matters are even better again. Then using a Ni-cad battery or Lith-Ion
battery will mean greater electrical capacity for a smaller battery package.
The fan belts for the water pump and power steering can be eliminated. Also
using an electric a/c compressor will make matters better too and again
another fan belt eliminated. None of this is rocket science and can be
implemented immediately in all cars.

Implementing electrically powered water pumps, oil pumps, PS
pumps,compressors, etc. do reduce the parasitic draw on an engine. Electric
ancillaries will make no difference to the price of a car once production is
up and running.

But improving the IC engine is not what they want to spend R&D money on.
Engines are designed to reach 50,000 miles before NVH falls away, then the
marketing men can sell another car. Electric ancillaries could have been
implemented 20 years ago, but the auto industry does not like change - why
the IC engine is a crock, where 75% of the energy in the tank is wasted.
R&D money is on all electric and hybrids. BMW are fiddling with edges in
start-stop, etc, because they have done little R&D on hybrids. The Germans
were way behind and are trying to catch up.

Look at supercapacitors, as they can claw back 99.99% of the kinetic energy
and give it all back. Buses are running on them in Shanghai. A Texas
company "claims" to have developed a supercapacitor with the same energy
density and size as a normal lead-acid battery. That mean the chemical
battery can be replaced. BTW, the Prius was originally to have a
supercapacitor. A combination of supercapacitor and battery may be
implemented soon. They have improved in 15 years.

The way foward is the Vaux Ampera. This setup can be greatly improved by
superior batteries and a smaller more efficeint range extender.