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Terryc said:

If you want a real hybrid car, then you get an electric vehicle and add
a IC powered generator. That will double your milage. This hapens
becuase the IC is set to run at its most efficent speed.

Yep:
http://www.motherearthnews.com/Alternative-Energy/1979-07-01/An-Amazing-75-MPG-Hybrid-Electic-Car.aspx

On 2007-07-05, Theo Bekkers (aka Bruce)
was almost, but not quite, entirely unlike tea:

Quoted message said:

TimC said:

PeteSig (wrote

Quoted message said:

"Theo Bekkers" wrote:

Quoted message said:

Quoted message said:

> There's always got to be at least one exception. I love the way
> they say "Power from the electric grid" and "Zero emission" in
> almost the same sentence.

Yes it's an issue. Especially with SUV-sized electric cars that can
accelerate from 0-60mph (0-100kmh) in 10 seconds and cruise at 95mph
(150kmh)!!! Electric or not, that's going to be very energy-intensive
transport. Surely it's better to ride a bike, or catch a train, or
drive a smaller car eg. Smart Car.

The accelaration is irrelevant in an electric car. So it has a lot of
torque. And a lot of force is necessary to be able to produce that.
But once up to speed, you're going to have to slow down or climb a
hill sometime. You get that energy back.

Ya what? Once you're doing over about 40 km/h in any car, regardless of how
aerodynamic it is, the main drag is air resistance. You constantly lose
that, even when you're going down hill. You never get that energy back.

Yes, but the rate of accelaration is irrelevant. Well, the small
difference in time you spend sub 40km/h between a fast and slow
accelaration will make a minute difference in how much energy you lose
to wind in that time. Once you're doing a static speed > 40km/h,
you're going to be putting out a constant amount of power to offset
losses. You'll then slow down eventually, and then you'll recover a
portion of the amount you used to get up to speed in the first place.
Don't brake too quickly though, otherwise the mechanical brakes will
have to be phased in, because you won't be able to recover the energy
quick enough otherwise.

But the larger amount of power you put into accelerating quickly is
offset by the decreased time you do this for. Electric motors are
pretty linear about this, unlike ICEs who become increasingly
innefficient the harder the throttle is pushed.

--
TimC
You see, wire telegraph is a kind of a very, very long cat. You pull
his tail in New York and his head is meowing in Los Angeles. Do you
understand this? And radio operates exactly the same way: you send
signals here, they receive them there. The only difference is that
there is no cat. -- Albie E. on radios.

Quoted message said:

But the larger amount of power you put into accelerating quickly is
offset by the decreased time you do this for. Electric motors are
pretty linear about this, unlike ICEs who become increasingly
innefficient the harder the throttle is pushed.

Ok just to prove I am awake.
ICEs become increasingly efficient "at the same rpm" the harder the throttle
is pushed.

Quoted message said:

Terryc said:

If you want a real hybrid car, then you get an electric vehicle and
add a IC powered generator. That will double your milage. This hapens
becuase the IC is set to run at its most efficent speed.

Yep:
http://www.motherearthnews.com/Alternative-Energy/1979-07-01/An-Amazing-75-MPG-Hybrid-Electic-Car.aspx

Wow, 2800 watts will propel a one tonne Opel at 80 km/h.Why does a standard
Opel have 100,000 watts? Hmm, I've got one of those B&S 5 hp jobbies on the
mulcher.. , and another on the cultivator. How fast can I go if I take the
14.5HP B&S out of the ride-on mower?

Theo

Theo Bekkers said:

Quoted message said:

Terryc said:

If you want a real hybrid car, then you get an electric vehicle and
add a IC powered generator. That will double your milage. This hapens
becuase the IC is set to run at its most efficent speed.

Quoted message said:

Yep:
http://www.motherearthnews.com/Alternative-Energy/1979-07-01/An-Amazi...

Wow, 2800 watts will propel a one tonne Opel at 80 km/h.Why does a standard
Opel have 100,000 watts? Hmm, I've got one of those B&S 5 hp jobbies on the
mulcher.. , and another on the cultivator. How fast can I go if I take the
14.5HP B&S out of the ride-on mower?

Theo

Probably because electric motors are rated at their continuous output,
while ICE's are rated at their peak. Electric motors can produce 2 to
3 times their rated output for sustained bursts without modification
or damage, care to try that with your mighty B&S? :-)

Quoted message said:

Theo Bekkers wrote:

Quoted message said:

Quoted message said:

Wow, 2800 watts will propel a one tonne Opel at 80 km/h.Why does a
standard Opel have 100,000 watts? Hmm, I've got one of those B&S 5
hp jobbies on the mulcher.. , and another on the cultivator. How
fast can I go if I take the
14.5HP B&S out of the ride-on mower?

Quoted message said:

Probably because electric motors are rated at their continuous output,
while ICE's are rated at their peak. Electric motors can produce 2 to
3 times their rated output for sustained bursts without modification
or damage, care to try that with your mighty B&S? :-)

Err, the point I was trying to make is that I'm dubious that (as the website
claims) a 5hp B&S driving a generator can continuously propel an Opel
(presumably an Astra) at 80 km/h. Is it fair to assume that the generator
will not produce more constant power than the ICE? I think (from memory)
that the 5hp B&S is about 200cc, I know the 14.5hp in the ride on mower is
495cc. Do you think a 200cc Low-tech engine such as a B&S will propel an
Astra at a constant 80 km/h?

Theo

Theo

Theo Bekkers said:

Quoted message said:

Theo Bekkers said:

Wow, 2800 watts will propel a one tonne Opel at 80 km/h.Why does a
standard Opel have 100,000 watts? Hmm, I've got one of those B&S 5
hp jobbies on the mulcher.. , and another on the cultivator. How
fast can I go if I take the
14.5HP B&S out of the ride-on mower?

Probably because electric motors are rated at their continuous output,
while ICE's are rated at their peak. Electric motors can produce 2 to
3 times their rated output for sustained bursts without modification
or damage, care to try that with your mighty B&S? :-)

Err, the point I was trying to make is that I'm dubious that (as the website
claims) a 5hp B&S driving a generator can continuously propel an Opel
(presumably an Astra) at 80 km/h. Is it fair to assume that the generator
will not produce more constant power than the ICE? I think (from memory)
that the 5hp B&S is about 200cc, I know the 14.5hp in the ride on mower is
495cc. Do you think a 200cc Low-tech engine such as a B&S will propel an
Astra at a constant 80 km/h?

No I don't think it could when used as the tractive force. I don't
believe the claim that the generator powers the drive motor directly
up to 50mph either, I think a more likely scenario is that the
generator feeds the batteries to extend their range and the drive
motor pulls current from them.

The drive motor is rated at 400A, and the system voltage is 48V so
he's got 19.2kW (rated) to play with. It doesn't mention things like
current limits in his controller (perhaps there are none), but if the
motor is rated for 400A, it can handle 8-1200A on acceleration
(38.4-57.6kW) provided his batteries can deliver.

That all doesn't sound like much in the ICE world, but consider this
http://www.plasmaboyracing.com/whitezombie.php car which has "only"
240Hp, yet 772 ft. lbs of torque. If your 14.5Hp B&S could develop
the same torque as the electric motor driving the Opel it could hurtle
your mower along at 80kph no worries.

Theo Bekkers said:

Wow, 2800 watts will propel a one tonne Opel at 80 km/h.Why does a standard
Opel have 100,000 watts? Hmm, I've got one of those B&S 5 hp jobbies on the
mulcher.. , and another on the cultivator. How fast can I go if I take the
14.5HP B&S out of the ride-on mower?

I must admit I blinked when I saw that. But, you lose the weight of the
engine, clutch and gear box and associated accesories, so that would be
a great weight in cast metal removed. Plus, there didn't seem to be that
much battery capacity added in.

Terryc said:

Theo Bekkers wrote:

Quoted message said:

Quoted message said:

Wow, 2800 watts will propel a one tonne Opel at 80 km/h.Why does a
standard Opel have 100,000 watts? Hmm, I've got one of those B&S 5
hp jobbies on the mulcher.. , and another on the cultivator. How
fast can I go if I take the 14.5HP B&S out of the ride-on mower?

Quoted message said:

I must admit I blinked when I saw that. But, you lose the weight of
the engine, clutch and gear box and associated accesories, so that
would be a great weight in cast metal removed. Plus, there didn't
seem to be that much battery capacity added in.

Hehe, when you blinked you must have missed the part where it said the
modifications only _added_ 50kg to the original weight of the vehicle. The
200cc B&S generator producing 2800w is not going to propel that at a steady
80 klicks as he claims. And that severely taxes my 'believe-it' meter for
the rest of his claims.

Theo

Quoted message said:

That all doesn't sound like much in the ICE world, but consider this
http://www.plasmaboyracing.com/whitezombie.php car which has "only"
240Hp, yet 772 ft. lbs of torque. If your 14.5Hp B&S could develop
the same torque as the electric motor driving the Opel it could hurtle
your mower along at 80kph no worries.

Well, if I could store the torque in a battery for future use then maybe it
could. The problem is that it is not constant as claimed and the torque
battery is going to run low eventually, probably sooner, and I'll be back to
whatever the ICE can put out.

I do have a working understanding of series-wound AC and DC motors. The
company I used to work for invented them back in 191x something. A fellow
named Charles Kettering. The old max torque at zero revs, just like a steam
engine. :-)

Theo

Theo Bekkers said:

Terryc wrote:

Quoted message said:

Hehe, when you blinked you must have missed the part where it said the
modifications only _added_ 50kg to the original weight of the vehicle. The
200cc B&S generator producing 2800w is not going to propel that at a steady
80 klicks as he claims. And that severely taxes my 'believe-it' meter for
the rest of his claims.

Yep, pass the salt.