Re: Prius seldom runs on batteries alone?
 

In article <Xns98D9ECFD76CCCjyanikkuanet@64.209.0.86>
jyanik@abuse.gov "Jim Yanik" writes:

> ames@deltrak.demon.co.uk (Andrew Stephenson) wrote in
> news:1171652924snz@deltrak.demon.co.uk:
>
> > In article <Xns98D97FF09C921jyanikkuanet@64.209.0.86>
> > jyanik@abuse.gov "Jim Yanik" writes:
> >
> >> How about charged from 120VAC line?
> >> When you get home or where an outlet is available.
> >> Then you use cheaper,more efficiently generated mains power for
> >> charging,not expensive gasoline.
> >
> > The exact numbers are not to hand but, in general, the efficiency
> > of charging from a wall socket is not as good as people generally
> > think. It may be $cheaper to the householder than what is put in
> > in fuel tank; but that's a red herring in the efficiency puzzle.
> >
> > Consider these stages when charging:
> >
> > * burn fuel at the power station and convert to electricity (hard
> > to compute the efficiencies if the energy source is, say, hydro
> > or solar or one of those, so skip them for now);
> >
> > * convey the electricity to wall socket and charger unit (if long
> > journey across country, losses not negligible);
> >
> > * convert electricity to form suitable for battery (low volt DC),
> > then convert to chemical energy, then back to electricity (huge
> > losses overall).
> >
> > Compare this with the clever juggling the full hybrid setup does.
> > Often the battery stays idle, as engine drives generator and that
> > drives electric motor. If it does involve the battery, we do not
> > have to pay for transmission losses. The higher-than-usual Prius
> > petrol engine efficiency... hmm, I'd be guessing irresponsibly if
> > I estimated how it matches up to the power station and would like
> > to know more.
> >
> > Just a thought, right?
>
> I suspect that electric generation is more efficient any from 120VAC source
> than any hybrid auto,and also outputs far less pollutants.
>
> Transmission losses are present regardless of whether the auto is charged
> from the line or not.Losses from corona discharge/leakage are far greater,I
> suspect.
>
> and you neglect the conversion losses that the auto has in going from
> electric to mechanical and back,also the self-discharge the batery pack
> has.

I considered listing each last tiny cause of inefficiency I could
imagine then decided to group them, eg: "* convert electricity to
form suitable for battery (low volt DC), then convert to chemical
energy, then back to electricity (huge losses overall)". Leaving
it to technically minded readers to fill in details seemed good.

We need more reliable, clear numbers.
--
Andrew Stephenson

Re: Re:What about the mileage!?!?!?!?!
 

In article <cvzBh.3066$tD2.710@newsread1.news.pas.earthlink.n et>
rlanni@access4less.net "R PRINCETON" writes:

> Unbelievable! 11 answers and counting and no-one answers my original
> question! Are you all a bunch of politicians!?!?!?!
>
> OK, enough ranting....
>
> Ignoring, increased wear and tear on the batteries or engine, total energy
> equations involving my old coal powered power plant; and any disturbances in
> subspace temporal harmonics....
>
> DID THE EV only switch increase peoples mileage? and by how much?

Did you actually READ all the responses, to your questions and
the others you no doubt found when you no doubt Googled on the
recent traffic in this NG, and THINK about them?

The implication was that it's not worth doing. The car is set
to care for itself and the battery. "Mileage" is another word
for "efficiency" in this context. Greater efficiency turns on
making better overall use of the fuel put into the tank. Read
my past posts on my EV experiments (see recent Google). EV is
purely there to solve local problems unrelated to efficiency.

GOT IT? Thank you. That ends this party political broadcast.
--
Andrew Stephenson

Re: Prius seldom runs on batteries alone?
 

"RT" <noyabusiness@yahoo.com> wrote in message
news:lmcat2999tukg436snqrbeehj5413rlkbk@4ax.com...
> On Thu, 15 Feb 2007 05:50:19 -0700, "Michael Pardee"
> <michaeltnull@cybertrails.com> wrote:
>>
>>Cold weather, particularly as the temperature drops below freezing, will
>>take the edge off fuel efficiency. I'm barely managing 30 mpg with mainly
>>3
>>mile trips in subfreezing weather right now, but when the weather warms up
>>it will go back into the mid-40s. OTOH, what other car would provide 30
>>mpg
>>under those conditions?
>
> In cold weather get 30mpg ? uh, the corolla will easily do that.
>

Not in three mile trips from a cold start on snowy streets, seldom exceeding
28 mph and sometimes with chains, I bet.

The weather has cleared and I'm into the 40s again (three mile trips and
all).

Mike

Re: Prius seldom runs on batteries alone?
 

"Bill Tuthill" <ccreekin@yahoo.com> wrote in message
news:45d5ee8c@news.meer.net...
> In alt.autos.toyota RT <noyabusiness@yahoo.com> wrote:
>>
>> In cold weather get 30mpg ? uh, the corolla will easily do that.
>
> A driver is a total weenie if he or she cannot get > 50 MPG
> from a Prius, even in cold weather.
>

Short trips are the big killer (same as with conventional power trains).
Cold weather means the warm-up time is extended, and short trips mean the
driving is mainly in warm-up mode. The rule of thumb is that a cold engine
will burn about twice the fuel of a warm one, and the Prius follows that
pretty closely.

Mike

Re: Re:What about the mileage!?!?!?!?!
 

"R PRINCETON" <rlanni@access4less.net> wrote in message
news:cvzBh.3066$tD2.710@newsread1.news.pas.earthli nk.net...
> Unbelievable! 11 answers and counting and no-one answers my original
> question! Are you all a bunch of politicians!?!?!?!
>
> OK, enough ranting....
>
> Ignoring, increased wear and tear on the batteries or engine, total energy
> equations involving my old coal powered power plant; and any disturbances
> in
> subspace temporal harmonics....
>
> DID THE EV only switch increase peoples mileage? and by how much?
>
>
> thank you
>
> -ralph
>
>
I've looked into the EV switch (available aftermarket) so I can move the car
from the curb into the driveway without the usual condensation of acids in
the exhaust. People who have put the switch in say it doesn't affect fuel
economy either way - it's just for suppressing the engine operation when it
isn't wanted.

Mike

Re: Prius seldom runs on batteries alone?
 

In alt.autos.toyota "mark_digital©" <976-XXX@comcastnot.com> wrote:
>
> There's always a possibility the engine will start anyway
> even if the car is sitting still.

I put it in Park to prevent this happening.

> If both battery packs are topped off ahead of time then
> there's no place else to store the electricity. Then the
> so-called savings from using AC utility power are diminished.

Right. Too bad the driver can't control charging by gas motor
and use of battery power, because the driver could predict this
better than the Prius computer.

Re: Prius seldom runs on batteries alone?
 

In alt.autos.toyota Jim Yanik <jyanik@abuse.gov> wrote:
>
> I suspect that electric generation is more efficient any from 120VAC source
> than any hybrid auto,and also outputs far less pollutants.

Do you own a Segway? They charge from 120V, I believe,
and go about 20 miles per charge. You'd get wet in the rain.

Re: Prius seldom runs on batteries alone?
 

In alt.autos.toyota Andrew Stephenson <ames@deltrak.demon.co.uk> wrote:
>
> That's encouraging (for future times when/if I do similar trips)
> but puzzling too. Last June, when the weather here was warm and
> dry, I drove about 400 miles in one day over mostly level ground
> and at 50/60-ish speeds (as fast as it was safe+legal+feasible),
> getting around that 56mpgUK -- which, incidentally, I learn I've
> been converting to mpgUS wrongly, making it more like 46.8mpgUS.

What size tyres do you have mounted on that Prius, and what brand?
And do they really still sell gasoline in the U.K. by the imperial
gallon and not by the liter, or I suppose you would spell it litre
or some modern French- or Continental-based measurement of volume?

Re: Re:What about the mileage!?!?!?!?!
 

" Did you actually READ all the responses, to your questions and
the others you no doubt found when you no doubt Googled on the
recent traffic in this NG, and THINK about them?"

YES I DID. I have googled, I have read; that's why I included the reference
to coal powered electric plants. (Of course, being an old fart, I may have
missed "IT".) What I concluded is that in other countries the EV switch is
provided by Toyota. Why? Is it because using it will improve gas mileage?

I have noticed that the ICV in my Prius runs way more often than I expected,
and for more than just recharging the batteries. The cute animation in the
LCD display clearly shows that most of the time the ICV is powering the
wheels, i.e., providing more power than the electric motor by itself can
provide. I am suspicious that this is done so as to improve the Prius's
"drivability" in the US; i.e., greater acceleration. Us Americans are
accustomed to "tearing" away from the traffic light. While in other
countries slower accelerating vehicles are more the norm. I have also
noticed that when I take my foot off the gas after a stop the Prius 'creeps'
just like a normal automatic transmission ICV only vehicle (something that a
manual transmission driver does not need). Again, a feature to improve
drivability at the expense of mileage.

Given that it is well known that jack-rabbit starts result in significantly
lower gas mileage vs a more constant power curve, I would be willing to
accept slower starts for more gas mileage. Ergo, my interest in an EV
switch. It is also well known that an ICV engine runs much more
efficiently at a specific RPM where it generates maximum torque per gallon
of gas; so it would make sense to operate the ICV at that speed exclusively
for recharging the batteries and never for pulling the vehicle. That is why
railroads use diesel-electric engines as opposed to diesel only engines.
(Why tractor trailers don't also do this is a mystery to me.) (Yes there is
a point where the diesel engine generates electricity as fast as the
electric drive wheels consume it and that point varies with each engine
based upon its expected use.)

So back to my original question: Has anyone installed an EV switch and used
it long enough (a year or more) and noticed a marked improvement in gas
mileage (10% or more).

(Why 10%? Because that show much I improved my Bonneville's mileage simply
by using my cruise control as much as possible to accelerate the vehicle and
maintain a more constant speed than I myself could do on the highway.)

BTW; I am a Physicist by training. I am not interested in "Implications" I
want facts!


-thank you


"Andrew Stephenson" <ames@deltrak.demon.co.uk> wrote in message
news:1171719278snz@deltrak.demon.co.uk...
> In article <cvzBh.3066$tD2.710@newsread1.news.pas.earthlink.n et>
> rlanni@access4less.net "R PRINCETON" writes:
>
> > Unbelievable! 11 answers and counting and no-one answers my original
> > question! Are you all a bunch of politicians!?!?!?!
> >
> > OK, enough ranting....
> >
> > Ignoring, increased wear and tear on the batteries or engine, total
energy
> > equations involving my old coal powered power plant; and any
disturbances in
> > subspace temporal harmonics....
> >
> > DID THE EV only switch increase peoples mileage? and by how much?
>
> Did you actually READ all the responses, to your questions and
> the others you no doubt found when you no doubt Googled on the
> recent traffic in this NG, and THINK about them?
>
> The implication was that it's not worth doing. The car is set
> to care for itself and the battery. "Mileage" is another word
> for "efficiency" in this context. Greater efficiency turns on
> making better overall use of the fuel put into the tank. Read
> my past posts on my EV experiments (see recent Google). EV is
> purely there to solve local problems unrelated to efficiency.
>
> GOT IT? Thank you. That ends this party political broadcast.
> --
> Andrew Stephenson
>

Re: Prius seldom runs on batteries alone?
 

In article <45d75e3c@news.meer.net> ccreekin@yahoo.com "Bill Tuthill" writes:

> In alt.autos.toyota Andrew Stephenson <ames@deltrak.demon.co.uk> wrote:
> >
> > That's encouraging (for future times when/if I do similar trips)
> > but puzzling too. Last June, when the weather here was warm and
> > dry, I drove about 400 miles in one day over mostly level ground
> > and at 50/60-ish speeds (as fast as it was safe+legal+feasible),
> > getting around that 56mpgUK -- which, incidentally, I learn I've
> > been converting to mpgUS wrongly, making it more like 46.8mpgUS.
>
> What size tyres do you have mounted on that Prius, and what brand?
> And do they really still sell gasoline in the U.K. by the imperial
> gallon and not by the liter, or I suppose you would spell it litre
> or some modern French- or Continental-based measurement of volume?

A multipart question? Good. Ans: Prius OEM (see other thread on
Prius tyres); Goodyear?; no; doesn't everyone?; historically yes.

FWIW, "litres/100Km" sounds daft. Many UKians still say "mpg".
--
Andrew Stephenson

Re: Re:What about the mileage!?!?!?!?!
 

In article <lEJBh.3207$tD2.1013@newsread1.news.pas.earthlink. net>
rlanni@access4less.net "R PRINCETON" writes:

> [...]

I'm tempted to throw this out to anyone else in the Toyota NG who
isn't thoroughly fed up with explaining the same notions over and
over. But try this (with my own questions):

> "ICV"

Don't know that term. "Internal Combustion [something]"? If you
mean the petrol [US:gas] engine, you cannot rely on how often the
mimic diagram shows it running, as a guide to relative energy o/p
of it vs the electric generator/battery/motor side of things.

Please read this bit carefully and try to accept it: the Prius is
set up to manage its own internal systems. The "EV" button seems
to have been a marketing experiment, nothing more. As far as the
NG can tell, it is fitted to EU/UK models and not to US ones. My
experimental results, which you should have found if you Googled,
show its range is functionally pathetic on the open road; it only
serves any purpose where you want to discourage (NB, not prevent)
the engine from firing up. It has no overall impact on the miles
you get out of each gallon (except in a very marginal way, due to
interference with the car's control system). It will not help in
passing Go, nor will it collect for you $200.

The petrol engine and electric motor run separately, or together,
according to whatever the car's control system thinks appropriate
so don't try to mess with it. If you don't like this arrangement
then lift the bonnet [US:hood] and put an axe through that large,
shiny box above the electric motor/generator/planetarygear lump.

> BTW; I am a Physicist by training. I am not interested in
> "Implications" I want facts!

Then you are unusual. All the Physicists (and physicists) I have
ever known have also been interested in the implications of data,
especially those which _appear_ to be anomalous.

> -thank you

You're welcome. If nobody objects, I'm going off duty now.
--
Andrew Stephenson

Re: Re:What about the mileage!?!?!?!?!
 

R:
Polymer Science Engineer here. As a physicist, you might have run across
situations where an answer comes through discussion, as well as through a
straight answer. The discussion is what occurs here and this is the
normal course of events in this Newsgroup. This is not a flaw, it is a
feature.

Patience Grasshopper.


"R PRINCETON" <rlanni@access4less.net> wrote in message
news:lEJBh.3207$tD2.1013@newsread1.news.pas.earthl ink.net...
>" Did you actually READ all the responses, to your questions and
> the others you no doubt found when you no doubt Googled on the
> recent traffic in this NG, and THINK about them?"
>
> YES I DID. I have googled, I have read; that's why I included the
> reference
> to coal powered electric plants. (Of course, being an old fart, I may
> have
> missed "IT".) What I concluded is that in other countries the EV switch
> is
> provided by Toyota. Why? Is it because using it will improve gas
> mileage?
>
> I have noticed that the ICV in my Prius runs way more often than I
> expected,
> and for more than just recharging the batteries. The cute animation in
> the
> LCD display clearly shows that most of the time the ICV is powering the
> wheels, i.e., providing more power than the electric motor by itself can
> provide. I am suspicious that this is done so as to improve the
> Prius's
> "drivability" in the US; i.e., greater acceleration. Us Americans are
> accustomed to "tearing" away from the traffic light. While in other
> countries slower accelerating vehicles are more the norm. I have also
> noticed that when I take my foot off the gas after a stop the Prius
> 'creeps'
> just like a normal automatic transmission ICV only vehicle (something
> that a
> manual transmission driver does not need). Again, a feature to improve
> drivability at the expense of mileage.
>
> Given that it is well known that jack-rabbit starts result in
> significantly
> lower gas mileage vs a more constant power curve, I would be willing to
> accept slower starts for more gas mileage. Ergo, my interest in an EV
> switch. It is also well known that an ICV engine runs much more
> efficiently at a specific RPM where it generates maximum torque per
> gallon
> of gas; so it would make sense to operate the ICV at that speed
> exclusively
> for recharging the batteries and never for pulling the vehicle. That is
> why
> railroads use diesel-electric engines as opposed to diesel only engines.
> (Why tractor trailers don't also do this is a mystery to me.) (Yes
> there is
> a point where the diesel engine generates electricity as fast as the
> electric drive wheels consume it and that point varies with each engine
> based upon its expected use.)
>
> So back to my original question: Has anyone installed an EV switch and
> used
> it long enough (a year or more) and noticed a marked improvement in gas
> mileage (10% or more).
>
> (Why 10%? Because that show much I improved my Bonneville's mileage
> simply
> by using my cruise control as much as possible to accelerate the vehicle
> and
> maintain a more constant speed than I myself could do on the highway.)
>
> BTW; I am a Physicist by training. I am not interested in
> "Implications" I
> want facts!
>
>
> -thank you
>
>
> "Andrew Stephenson" <ames@deltrak.demon.co.uk> wrote in message
> news:1171719278snz@deltrak.demon.co.uk...
>> In article <cvzBh.3066$tD2.710@newsread1.news.pas.earthlink.n et>
>> rlanni@access4less.net "R PRINCETON" writes:
>>
>> > Unbelievable! 11 answers and counting and no-one answers my
>> > original
>> > question! Are you all a bunch of politicians!?!?!?!
>> >
>> > OK, enough ranting....
>> >
>> > Ignoring, increased wear and tear on the batteries or engine, total
> energy
>> > equations involving my old coal powered power plant; and any
> disturbances in
>> > subspace temporal harmonics....
>> >
>> > DID THE EV only switch increase peoples mileage? and by how much?
>>
>> Did you actually READ all the responses, to your questions and
>> the others you no doubt found when you no doubt Googled on the
>> recent traffic in this NG, and THINK about them?
>>
>> The implication was that it's not worth doing. The car is set
>> to care for itself and the battery. "Mileage" is another word
>> for "efficiency" in this context. Greater efficiency turns on
>> making better overall use of the fuel put into the tank. Read
>> my past posts on my EV experiments (see recent Google). EV is
>> purely there to solve local problems unrelated to efficiency.
>>
>> GOT IT? Thank you. That ends this party political broadcast.
>> --
>> Andrew Stephenson
>>
>
>

Re: Prius seldom runs on batteries alone?
 

"Gordon McGrew" <RgEmMcOgVrEew@mindspring.com> wrote in message
news:n5q7t2dpf42gmp0vu71qipj66k6p4tbt0i@4ax.com...
>
> I rode in a friend's Prius and he showed me that the engine started up
> before he hit 5 mph even under mild acceleration. I thought the
> difference between the "full" hybrids like Prius and "mild" hybrids
> like the Civic was the ability of the former to operate as a pure
> electric over a modest range of conditions. It would seem that the
> Prius' all electric performance is very modest indeed. Is this
> correct?

As most have said, the battery has to be charged above a specific threshold
for the ICE to turn off. I have found that you also need to be in cruise
control. Normal driving with foot on the accelerator just doesn't produce
electric-only operation except at very slow side-street speeds. I guess
that's because the Prius computer doesn't trust human beings to drive at a
single fixed speed. My favorite EV speed in cruise control is 34 MPH.

To make sure the battery is charged and ready for EV operation, you need to
apply fairly heavy braking from freeway speed.. Just slowing down slowly
doesn't charge up the battery very efficiently. Unfortunately this kind of
driving is uncomfortable for passengers, so don't do it unless you're alone.
Also, make sure you brake *before* you hit a curve or encounter cross
traffic.

Re: Prius seldom runs on batteries alone?
 

"Andrew Stephenson" wrote ...
> "Jim Yanik" writes:
>> Andrew Stephenson wrote ...
>> > "Jim Yanik" writes:
>> >> How about charged from 120VAC line?
>> >> When you get home or where an outlet is available.
>> >> Then you use cheaper,more efficiently generated mains power for
>> >> charging,not expensive gasoline.
>> >
>> > The exact numbers are not to hand but, in general, the efficiency
>> > of charging from a wall socket is not as good as people generally
>> > think. It may be $cheaper to the householder than what is put in
>> > in fuel tank; but that's a red herring in the efficiency puzzle.
>> >
>> > Consider these stages when charging:
>> >
>> > * burn fuel at the power station and convert to electricity (hard
>> > to compute the efficiencies if the energy source is, say, hydro
>> > or solar or one of those, so skip them for now);
>> >
>> > * convey the electricity to wall socket and charger unit (if long
>> > journey across country, losses not negligible);
>> >
>> > * convert electricity to form suitable for battery (low volt DC),
>> > then convert to chemical energy, then back to electricity (huge
>> > losses overall).
>> >
>> > Compare this with the clever juggling the full hybrid setup does.
>> > Often the battery stays idle, as engine drives generator and that
>> > drives electric motor. If it does involve the battery, we do not
>> > have to pay for transmission losses. The higher-than-usual Prius
>> > petrol engine efficiency... hmm, I'd be guessing irresponsibly if
>> > I estimated how it matches up to the power station and would like
>> > to know more.
>> >
>> > Just a thought, right?
>>
>> I suspect that electric generation is more efficient any from 120VAC
>> source
>> than any hybrid auto,and also outputs far less pollutants.
>>
>> Transmission losses are present regardless of whether the auto is
>> charged
>> from the line or not.Losses from corona discharge/leakage are far
>> greater,I
>> suspect.
>>
>> and you neglect the conversion losses that the auto has in going from
>> electric to mechanical and back,also the self-discharge the batery pack
>> has.
>
> I considered listing each last tiny cause of inefficiency I could
> imagine then decided to group them, eg: "* convert electricity to
> form suitable for battery (low volt DC), then convert to chemical
> energy, then back to electricity (huge losses overall)". Leaving
> it to technically minded readers to fill in details seemed good.
>
> We need more reliable, clear numbers.
> --
> Andrew Stephenson
>

I agree, we can wave our hands around and make points both ways, but
without real comparative numbers (which I for one do not have) it is all
just speculation.

I'm thinking that I am remembering reading that Toyota is considering the
ability to plug it in for the next version. Dunno if that would actually
happen tho.
Tomes

Re: Prius seldom runs on batteries alone?
 

"Bill Tuthill" wrote ...
>"mark_digital©" wrote:
>>
>> There's always a possibility the engine will start anyway
>> even if the car is sitting still.
>
>I put it in Park to prevent this happening.

Doing this has not occurred to me - I will try this. I figure that I
don't need to have the engine running when I am stopped, even if it thinks
that it needs to heat something up. It can wait to do that until I
acceletate and co-use that power.
>
>> If both battery packs are topped off ahead of time then
>> there's no place else to store the electricity. Then the
>> so-called savings from using AC utility power are diminished.
>
>Right. Too bad the driver can't control charging by gas motor
>and use of battery power, because the driver could predict this
>better than the Prius computer.

This is what I am thinking, I just don't know if I am right.
Tomes