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Discussion Starter #1
Prius 2 is pretty good, and quite an improvement on Prius 1. However, here are the things I think Toyota should incorporate into Prius 3 when it comes!

1) Ditch the teeny 1.8kWhr NiMH battery pack for a 50kWhr LiS pack.
2) Increase motor power output to 90kW (sufficient to take the car to over 100mph on battery power alone).
3) Lose the complicated/expensive transmission business and move to a series arrangement (currently parallel) where the engine is only there to power a generator, not to move the wheels through a gearbox.
4) Include a recharging socket so the car can be powered either by electricty from home or petrol as and when the consumer feels like it.
5) Modify the engine to run on either bioethanol or biodiesel.

Hey presto, the worlds first production plug-in hybrid!

More on my thoughts here....

http://www.benerridge.freeserve.co.uk/prius.htm
 

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> the worlds first production plug-in hybrid!

Looking through the history books, you'll see that the 1st generation (97-00) Prius has a plug. When the 2nd (01-03) was introduced, Toyota removed it.

THS/HSD is on the 2nd generation now, Prius itself is on 3rd generation. Your terminology is attempting to combine the two.
 

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Discussion Starter #3
THS/HSD is on the 2nd generation now, Prius itself is on 3rd generation. Your terminology is attempting to combine the two.
Sorry! My bad. Over here we go by body shape, and call the first body shape (ie 97-03) the Mk1 and split it into revisions, ie Mk1 Rev1 and Mk1 Rev2.

Very interested in the whole plug thing, I'd never heard that before. Will look into it, though I can't imagine why they put it on with such a small battery.... can you point me to a good link on this? Cheers....
 

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I'm actually curious myself where that original plug came from. I also wonder how much it actually accomplished with that configuration.

Was it a business decision driven by marketing factors of the time?

Maybe the engineers figured having this already built into the design would make adding a more powerful battery-pack easier to justify later.

I don't know of any documentation from that era stating what happened. And of course, I highly doubt any of it would be in English anyway. We may never find out why. After all, some of what Toyota decided already is what other automakers are deciding now. For competition sake, they probably wouldn't devulge their reasoning.
 

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John, where did you get this plug-in info from ? If there is no verifiable source of information we can have direct access to I will consider this point as a legend rather as the Holy Truth... :wink:
 

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Prius II??

Its my understanding that Toyota regards the 2004 as "Prius II;" that's with the new "Synergy" system. At least that's what the letter that I got from Toyota today says. its offering "a deal" to those of us who ordered Prius 2001's off of the internet early in the game. A loaded Prius will be over $25,000, by the way.
 

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$25K!! That's a bit steeper than the publicity stuff Toyota put out would suggest. What "Deal" did they offer you--might be nice to see if my dealer would negociate based on that...what form did the deal come in? What other pricing info did they give you...this is a lot more information that has been available previously.
 

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> $25K!! That's a bit steeper

You don't realize how much that includes. "Very Well Loaded" is an understatement.

Besides the normal extras, like a sweet sound system, you also get:

- Vehicle Skid Control

How many sedans even offer that?

- Smart Entry & Start

No vehicles, even luxury, offer this!

- Navigation System

This is just plain cool, especially since the unique placement of the new (bigger) Multi-Display makes it very easy to use.

Anywho, the base price of $20K isn't bad at all for a midsize. Plus you get things like cruise-control, a CD player, digital speedometer, and the Multi-Display standard.
 

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The Toyota website suggests that the "smart entry" system will be an option rather than standard. Has anyone heard how much a "bare-bones" Prius will be? Unfortunately, $25,000 is out of my range.
 

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Prius pricing

DAVID said:
The Toyota website suggests that the "smart entry" system will be an option rather than standard. Has anyone heard how much a "bare-bones" Prius will be? Unfortunately, $25,000 is out of my range.
2004 base Prius is still MSRP of $19995 + the delivery fee (around $500).
http://autos.groups.yahoo.com/group/toy ... sage/59773
http://autos.groups.yahoo.com/group/toy ... sage/59609

A fully loaded Prius, for $25240, includes these options:
Rear wiper
Side & curtain airbags
Smart Entry & Start
HID lamps
Fog lamps
Vehicle Skid Control (VSD)
Security alarm and Garage door opener
Navigation system (which includes the Bluetooth capability for mobile phones, and voice-command for audio, climate-control, navigation system controls)
JBL 9 speaker premium audio system w/6cd changer
 

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These lithium based batteries are not what we need on our hands. They are not nearly as environmentally friendly as NiMH. Not to mention the exceptional difference in weight and cost. Another benefit of NiMH is that they are not as prone to developing a memory as lithium or nickel cadmium based.

clett said:
Prius 2 is pretty good, and quite an improvement on Prius 1. However, here are the things I think Toyota should incorporate into Prius 3 when it comes!

1) Ditch the teeny 1.8kWhr NiMH battery pack for a 50kWhr LiS pack.
2) Increase motor power output to 90kW (sufficient to take the car to over 100mph on battery power alone).
3) Lose the complicated/expensive transmission business and move to a series arrangement (currently parallel) where the engine is only there to power a generator, not to move the wheels through a gearbox.
4) Include a recharging socket so the car can be powered either by electricty from home or petrol as and when the consumer feels like it.
5) Modify the engine to run on either bioethanol or biodiesel.

Hey presto, the worlds first production plug-in hybrid!

More on my thoughts here....

http://www.benerridge.freeserve.co.uk/prius.htm
 

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Discussion Starter #12
Joel, these Lithium Sulphur batteries are SO the next step in improving hybrid car designs! The only reason NiMH has been "chosen" by Honda and Toyota is that it's what they started their research on years ago (so have plenty installation data on), it's cheap and better than the even more primitive lead acid! I'll go over your other concerns one by one....

1) They are if anything more environmentally friendly than NiMH, as the equivalent LiS battery is one fifth the size of its NiMH counterpart and requires less energy to make for ultimate kWhrs final use. They are also easy to recycle at end of life. Of course nither battery makes any emissions.
2) Weight. The energy density of the NiMH battery in the Prius is about 55Wh/kg. The energy density of Lithium Sulphur is between 300-500Wh/kg, meaning an equivalent LiS battery would weigh about a sixth the weight of the current battery.
3) Memory effect. This is a problem displayed by the current set of lithium batteries available in laptops etc but these are not lithium sulphur, these are either lithium ion or lithium polymer, the two precursor technologies to LiS that only achieve around 180Wh/kg tops. The latest results from LiS research indicates that they have much improved cycle life and resistance to memory effect on account of how the electrodes are protected.
4) Cost. OK, I admit this is a problem right now! But LiS technology is being developed so that it can be used on standard lithium winders (essentially like making a plastic sandwich), and if the product were mass produced it could easily become much cheaper than NiMH per kWhr final storage.

A 50kWhr LiS pack would add about 100-150kg to the weight of the Prius, but it would give you a range in "stealth mode" of over 200 miles!

Details here for the technically inclined....

http://www.benerridge.freeserve.co.uk/lis.htm
 

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:? I am puzzled by such postings that ask for speeds of 100MPH. Do these people anticipate driving on the Autobahn in Germany? In what state is such a speed allowed? I am under the impression that the Prius is purchased for fuel economy and SULEV. How does this correlate with 100MPH and its loss of fuel efficiency? :roll:
 

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Discussion Starter #14
Today, if you want to change the world, you have to appeal to peoples pockets. In terms of the goal of making plug-in hybrids as widely used as possible, that means ensuring that they appeal to as wide a target consumer base as possible. As the current image of green cars is of slow and unpleasant to drive vehicles, it really is significant that we show the general public that plug-in hybrids can offer just as much performance as the cars they fear having to give up - hence the 100mph target.

The real gains in this department will come when some bright enterprising auto company will offer a hybrid sports car with around 150bhp petrol power and an extra 150bhp electric. Such a layout is already being considered by Honda for a new Accord type R, and Toyota for the next top of the range Celica, but don't expect anything before about 2005-2007. :)
 

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Clett,

I understand your interest in long-range electric vehicles and up-to-date battery technology :idea: , but I think your suggestions can be very misleading for most readers, and I would like to make some comments around 2 important ideas :
  • :!: a hybrid car is NOT an electric (or even part-electric) car
    :!: a plug-in hybrid is NOT a "non-plug-in" hybrid
What is a hybrid, first ? Although the Prius, the Insight and the HCH use electric motors, hybrid does not mean part-electric. Just like all computers today run on electricity, but the very concept of a computing machine has nothing to do with electricity. The main idea in the hybrid concept is that energy can be much more efficiently used than it is in conventional vehicles because of important fluctuations in the power necessary to propel the vehicle. In everyday driving, the power demand fluctuates from high positive values (quick overtaking, steep roads, high speed driving...) to low values (cruising at moderate speeds) or even negative ones when braking or driving downhill. The engine of a conventional car is designed to meet the maximum power requirements, and therefore is less efficient at medium or low power demands; and the negative power is simply wasted (transformed into heat) by the brakes : that makes 2 potential efficiency improvements on which engineers have been working.

I think a little sketch would be helpful to illustrate my explanations, but since I can't include any attachment, let's tell a story...

Let's think of the power fluctuations as a hilly curve, sometimes positive, sometimes negative, but with a positive mean value. The abscissae represent the time, and the ordinates the power: that makes any area under a portion of the curve measure an energy. The purpose of a hybrid system is to make this curve smoother for the engine, but not for the driver, by planing down the highest peaks and filling in the valleys. This is possible as long as there is no net energy creation, i.e., the same amount of energy stored in the battery when the power demand is less than the max. engine power output is used when the power demand exceeds the engine max. power output. It is just like making a new rather flat road in a hilly area, using soil excavated somewhere to fill in depletions somewhere else. Doing this, you improve significantly the two points I mentioned above. You can by the way use a different engine cycle (Atkinson for the Prius) which is not as good at producing high power output but better at thermodynamic efficiency. All this is possible in present hybrid cars using a big battery as an energy reservoir and an electric motor to "help" the engine and produce electricity.

But as long as the hybrid system is a non-plug-in one, it means that all the energy comes from gasoline (or petrol :wink: ), even the energy recovered during regenerative braking because kinetic energy was produced at the first place by the engine... As a consequence, the only aim an engineer must strive towards (in order to save fuel) is to make the engine run in its most efficient zone, not to use the electric motor as often as possible. Increasing battery capacity will not necessarily improve fuel economy: the energy capacity must be comparable to the size of the "hills" and "valleys" in a tipycal power demand curve, that's it. Although around 2kWh might seem "tiny", it is in fact enough for everyday driving conditions in a Prius: entirely depleting the battery or, conversely, being at maximum charge (and hence not being able to recover more energy), are EXTREMELY RARE events in a Prius driver's life. It happened to me once in more than 30 000 km, and because I intentionnally "tested" the car on the Mont Ventoux.

That means a 50 kWh battery in a non-plug-in hybrid car would be technical and economical nonsense; maybe 5 kWh in a couple of years when production costs will be much lower, but certainly never 10 times more.

The situation would be different for a plug-in hybrid, because electricity can be produced in various (and some of them non-polluting) ways. But this is a completely different car, with a completely different energy management strategy. In order to maximize efficiency and minimize emissions, a thermal engine must be warm. Therefore, even if you have plenty of electricity at your disposal in a huge battery, turning the engine off for a long time is not a good strategy. The only possibility to take advantage of a large capacity battery in a plug-in hybrid would then be to run only on electricity at the beginning (for short trips) and when the charge level is low enough to start the engine as in a "non-plug-in" hybrid, but without making it recharge the battery up to the start level (otherwise you will never have any benefit to plug it in!). This is technically feasible, but has one shortcoming: it makes the battery operate over a wide range of states of charge, and this is not very good for its life expectancy. :(

Now let's comment your suggestions :
1) Ditch the teeny 1.8kWhr NiMH battery pack for a 50kWhr LiS pack.
2) Increase motor power output to 90kW (sufficient to take the car to over 100mph on battery power alone).
3) Lose the complicated/expensive transmission business and move to a series arrangement (currently parallel) where the engine is only there to power a generator, not to move the wheels through a gearbox.
4) Include a recharging socket so the car can be powered either by electricty from home or petrol as and when the consumer feels like it.
5) Modify the engine to run on either bioethanol or biodiesel.
Point 1) has already been addressed above.
Point 2) : 90kW is not necessary for 100 mph. The current Prius 53kW thermal engine can take alone the car at 100 mph (without any drain on the battery). And motor power is one thing, but battery output power is another one (current one is 25 kW for the Prius, if I'm right).
Point 3) : The Prius is not a parallel hybrid, nor a series one... it combines both thanks to the remarkably clever "power split device". Furthermore, this PSD is mechanically much simpler than a conventional (manual or automatic) gearbox. The complexity is in the electronic control of the whole stuff, but this is a general tendency of today technology to replace mechanics by electronics, and is in general economically sound.
Point 4) has already been answered.
Point 5) seems to be a good idea, but the problem is to find alternative fuels : Toyota will not build a car if you can fill up the tank only in very special places. Today, Diesel engines have a better efficiency than Otto ones, and technology is available to make them "clean" by eliminating almost all particulates and nitrogen oxydes. They can be made much less noisy too. But there is still a technical problem with the high compression ratio, which makes them difficult to start and stop in a seamless, unobtrusive way.

If engineers can solve this problem, let's bet Prius III will be a Diesel-hybrid with a 3 or 4 kWh battery... :wink:

PS : Pleaze fill free (everybody) to correct my english... i'ts always funn to lurn something ! :D
 

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Discussion Starter #16
OK frenchie, I admit I may have misled some readers somewhat! :oops:

However it all makes sense if you remember I'm not suggesting LiS for use in todays hybrids, but in the plug-in hybrids of tomorrow.

I agree with your point that 1.8kWhr is by far enough capacity to smooth the power demands of normal driving and that NiMH technology is fine for this purpose in todays hybrids like the Civic and Prius. In fact, if you wanted to manufacture hybrid cars more cheaply, I'm the first to admit that you could probably get away with an even SMALLER battery in todays type of hybrid design!! (Ricardos Astra hybrid uses a 0.85kWhr NiMH pack).

But the problem remains that with todays designs of hybrids you are still tied to the gas pump and all the environmental concerns that that entails!!!!

The point I am trying to make is that cars NEED to start being made able to run from electricity so that we can start to take most advantage of RENEWABLE energy, not the destructive polluting stuff we go to war over pulling out of the ground. With a plug-in hybrid, you have the choice. Electric if you like (hence the big battery pack required). Or liquid fuel the next day - it's up to you.

So yes, todays hybrids are good in that they progress our technical ability in electric drivetrains and power electronics, but the real benefits for the planet will come when we move to hybrids that can be plugged in.

As for your comment that the Prius is not an electric car - remember it is when it's in stealth mode, regardless of where the battery charge came from!! 8) Why wouldn't you want to spend the first 400 miles of your day in full performance (hence the power requirements) stealth mode? :wink:

Apologies if I have not been clear.... 8) 8)
 

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I agree with you, clett 8). Don't apologize. Just wanted to emphasize some technical issues that are not so well understood by everyone. Concerning the stealth mode, I LOVE it and when I said "Prius is not an electric car", I just meant what you mean: all electricity comes from the gas/petrol engine, not from renewable energy sources (and that means it is better in most cases to use directly engine mechanical power than electricity coming from the battery). However plug-in hybrids are not the only solution for using renewable energy, if you consider -as you said- using biodiesel or other fuels made from crops in "non-plug-in" hybrids.
 

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"EV" Switch in 2004 Prius

It was mentioned, on one of the Yahoo Prius sites, that a 2004 Prius, that was shown to a group in England, had a switch that was marked "EV". The group was told that the switch was to force the Prius to run in electric mode. The car was on display only and was not available for test drives so they were not able to verify what the "EV" switch did.
The US version does not seem to have this switch. I was wondering if Frenchie or Clett (or anyone else) has heard anything more about this switch. There is speculation that it may only be available on the European version or that it was only for pre-production testing purposes.
I realize that the Prius could only go a few miles in electric mode, but that would still be enough for those short local trips.
 

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The EV button does work but turns off once you get to say max. 20mph. It is REALLY quiet to drive in this mode but I don't know how practical. It also runs down your battery (obviously) but it is real fun :wink:
 

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john1701a said:
- Smart Entry & Start

No vehicles, even luxury, offer this!
Actually, there are a few other vehicles which offer this. I believe some Lexuses offer it, and some newer GM (Caddies and perhaps the Corvette) offer it as well.

It is unique at this price point tho.
 
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