On Jan 2, 5:29*pm, Andy Champ wrote:
On 31/12/2011 08:34, harry wrote:





On Dec 30, 9:10 pm, Andy *wrote:
On 30/12/2011 07:58, harry wrote:

On Dec 29, 4:48 pm, wrote:
On Thu, 29 Dec 2011 01:33:17 -0800 (PST),
wrote:

The weight of the on board capacitors would in itself be an energy
store (kinetic energy).

And how do they get up to speed - magic pixie beans?

Stupid boy. You don't get anything for nothing.
But storing kinetic energy is far more efficient than charging/
discharging batteries.

Kinetic energy stored as vehicle momentum is of no use for accelerating
the vehicle. *At the time you need it it isn't there.

It's also of no use for climbing hills - the extra weight exactly
cancels out the extra KE.

In fact I can't think of a use for extra mass at all. *Except in a road
roller.

Andy

But it can be used for charging batteries. *Which is exactly what
happens in electric cars. *In ICE cars, it is lost.
Bad news during cornering though.

Harry,

Lets take two examples, a 1000kg car and a 2000kg one. *We'll give them
identical power trains.

Accelerate them to 10m/s (22mph, a traffic sort of speed) will take:

1/2 * 1000 * 10 * 10 = 50 kJ for the 1000Kg car
100kJ for the 2000Kg one.
Lighter is better.

We'll go along the road a bit. *Air drag is the same, rolling resistance
slightly higher for the heavier one.
Lighter is better.

Come to a stop. *Perhaps the recharge cycle is 80% efficient, so we get
back 40kJ for the lighter car, 80 for the heavy one.
The loss for the start-stop cycle is less for the lighter car.

As I say I can think of no case where heavy is better.

Andy- Hide quoted text -

- Show quoted text -

You have a point there. But the question was about the recharge of
"supercapacitors" which is allegedly wear 100% efficient.