3rd generation Prius... 2008

[trekbiker]

probably will have a Lithium Ion battery. Hopefully will be a PHEV as well

http://www.greencarcongress.com/2005/11/new_smaller_hyb.html

[DJ MEW]

1. But what is the fuel efficency of it?

If the hybrid system is smaller does that make the miles per gallon go down or up?

[trekbiker]

3. mpg will go up

if they offer a PHEV version the mpg should go way up.

[yurbud]

11. See Calcars.com for max mileage on PHEV--the most flexible vehicle

plug in when you can, drive on combustion when you have to.

If it was hooked up to a small diesel that only powered the batteries instead of directly running the wheels, it would be even more efficient.

http://calcars.org/

[Massacure]

12. But it won't go "up"

Efficiency is measured in miles per GALLON You cannot measure electricity in gallons.

edit: Oops, I meant to reply to TrekBiker.

[yurbud]

14. strictly speaking no, but in terms of the effect on you as user, yes.

electricity is cheaper than gas, and we have more option of how to make it when it isn't being made in the car itself.

[jobycom]

2. The link on the right was interesting, about a hybrid diesel

Peugot is making a hybrid diesel that will get 69 MPG. Run that off biodiesel, and you've got something. Unfortunately, they aren't expecting to market it four another four years.

[trekbiker]

4. I read that link too..

would be nice if Toyota would develop Diesel with thier hybrid technology. I've owned Toyota vehicles (2 cars, 5 trucks) for the last 25 years and would trust Toyota quality over the French any day. But the more variations in this technology the better. Hopefully costs will come down as the technology and market advances

[jobycom]

8. I think any development of diesel technology is progressive

Diesel fuel can be made without petro. You probably know already that Rudolph Diesel designed his engine to run off vegetable oils because he believed there might be a limited supply of oil. He may have overestimated the limit, but he's turning out to be right. The fact that there is an alternative to gasoline means that as oil fades, these alternatives will be produced more. It could very well be an easy, seamless transition, if we're really lucky. Might even create an economic boom and result in cleaner air. So I'm more excited about the technology's potential than about it's immediate availability, if you see what I mean.

I can't write today. Man. Everything is coming out stiff and formal. Sorry about that.

[yurbud]

10. yeah, can't you run biodiesel in a regular engine?

[Teaser]

5. cost/seating?

I wanted a prius a few years ago but it wouldn't seat enough people (had a baby coming, and the back seat was a joke).

So I looked at a Toyota hybrid...but it was too much for me to pay at the time...


So I'm still waiting for my hybrid...

[nickinSTL]

6. was that the 1st or 2nd generation?

the 1st generation Prius was a compact, the 2nd is a midsize.

Also, the Camry is coming out with a hybrid this year, and has the Highlander SUV in a hybrid now.

In addition, Honda has both the Civic and Accord available in hybrid, though I don't know much about their mileage/technology.

I know that Toyota's 2nd generation hybrid tech is apparently significantly more fuel efficient than the 1st. About the same mpg for a larger, more powerful vehicle.

I expect the 3rd generation to be even better.

[Teaser]

7. Probably 1st....

was when I was looking last...

[nickinSTL]

9. take a look now...

and don't forget Honda. I understand that they tend to have more hybrids immediately available, whereas you generally have to wait for Toyotas.

[rfkrfk]

13. lighter batteries, that don't do anything

Toyota invents the 800gram kilogram

Canada improves the Imperial gallon , by making
it a litre, same taxes

Coke's 500ml Superquart is a big seller

Hershey's improved candy bar, less calories, and less fat

....................................
c'mon folks, grow up

the reason the batts last the life of the car,
is that the batts don't do all that much

[Dead_Parrot]

15. WTF?

Do you actually have a clue how a hybrid works, and what a lighter, higher capacity battery does for it?

Edit:
the reason the batts last the life of the car,
is that the batts don't do all that much

Ahh, I see you don't. Sorry.

[rfkrfk]

16. Prius 1 to Prius 2, less battery storage from less batteries

how did Toyota , Generation 1 Prius to Gen 2,
make the battery pack lighter?

simple

fewer batteries

of course,it advertised as 'improved lightweight'
on top of that, less than 30 percent of the meager capacity is actually used

I kinda assume the Gen 1 was under speced, so the Gen 2 could be speced higher,
when it was really less of a car

idiots eat it up

with tha said, I don't know what will be done with the Gen 3,
but I certainly would not believe what Toyota says

[Dead_Parrot]

17. Well, the article cited

is discussing 2008. It seems unlikley, therefore, to include spec changes from the Gen 1 to Gen 2 Prius. Doubtless you will be providing a link to the article/paper you are referencing for interest value in the near future - along with your reasons for not trusting Toyota. :)

[rfkrfk]

18. you asked for it, you got it, try these links

correction, my comments refer to changes in the
2004 Prius model year.

if reducing battery capacity, in a hybrid,
is good, why have batteries at all?

first link
http://www.electrifyingtimes.com/prius_2004_westcoast.html

look halfway down the page, for paragraph starting with
'changes to the batteries'
The important points are, fewer modules, reduced weight, reduced voltage.
missing is, 'amp-hour rating', of the batts

second link, info in Wiki should be taken with a grain of salt,
but the numbers seem reasonable
http://en.wikipedia.org/wiki/Prius

look for the table, about two-thirds down the page, look for NHW11, NHW20
both, have amp-hour being the same, 6.5

if you are not convinced, just say so, I'll PM ya, if I ever find this stuff
presented in a better way

[skids]

19. A few things.

One, a reduced weight of the pack does not mean reduced capacity. It could and very well probably does mean superior battery technology.

Two, if you don't think the batteries do anything, then try driving one that you've run the batteries down in and check your mileage. They work.

Three, the energy difference is by no means drastic:

                        Original Classic HSD
Capacity amp hours 	6.0 	 6.5 	 6.5
Volts                   288 	 273.6 	 201.6

Energy                  1728     1774    1310

Four, that really doesn't tell you much because different batteries may have different tolerances allowing different charging ranges to be used -- and in addition there have been efficiency improvements in the motor/motor controllers. If shrinking the battery was such a bad and deceptive thing, why does an HSD have better mileage and better acceleration than my classic? They made the difference up with other improvements, that's why.

Five -- it's kinda hard to be legitimate in criticising a design made by a company half a world away by a team of engineers you don't know and which hasn't been released yet.

[rfkrfk]

20. capacity is reduced

capacity is
......................

voltage...

times {aka multiply}

amp-hours

.......................

Please tell me, how much regen braking power,
is captured duirng braking

please

I have looked several times

[skids]

21. Actually...

If you read my post, you would have noted that I did indeed multiply amp hours by voltage.

If you read your own posts, you would have noted that the batteries aren't fully excercised along their
entire charge range. Thus, how much of the energy capacity of the batteries can be bigger for a smaller
battery if they have figured out how to safely and without damaging the battery, improve on that range.

Not to mention other improvements in the system.

On regenerative braking:



http://www.vassfamily.net/ToyotaPrius/CAN/technomeasures.html

If you read your own wiki article link, you'd see the 2004 Prius, compared to the classic, even with the reduction in battery capacity, they somehow managed to improve the efficiency of the regen braking. On the Honda insight, they made some mods to increase efficiency by 11% one one model revision, forget which.

Here's an interesting article on the Original (Japan only) Prius braking, which was not as well engineered as the 2004, from a modder.

http://autospeed.drive.com.au/cms/A_2392/article.html

Some theoretical modelling is here:

http://web.mit.edu/chemistry/deutch/policy/66HybridCarsNow2004.pdf

[rfkrfk]

22. 27 braking horsepower, math help needed

Thanks for posting that stuff

from one of the charts, regen current is 100 amps
at 200 volts that is 20 kw, 26.8 horsepower {1300 kg vehicle}
15.4 watts / kilogram
one 'Gee' is 9.8 m/s/s

consider a one G panic stop

15.4 / 9.8 --> 1.57 meters / second
5.66 km /hr or 3.5 miles / hour

---------somebody check the math----------------

this is miraculous

when I am flying down the freeway at 7 miles per hour,
and I need to make a half G normal stop,
the regen braking is maxed out

edit, adding

a panic stop, from 60 mph, in a 1300 kg car,
458 horsepower

[skids]

23. Jives with specs.

About that ballpark. The rated kw of the electric motor is 50kW, and 20kW is about half. The actual breaking power, rather than regen power saved, would be a bit higher because the reverse torque gets transferred to the wheels whether or not it gets wasted before it makes it to the battery -- it would, of course be much nicer if it did get transferred to the battery, but as far as figuring out at what decel it tops out (and thus how much brake pad wear is saved) that needs to be figured in.

And yes avid hybrid drivers know to milk it we need to take nice slow stops whenever they can anticipate them. Which probably contributes to our lower than average accident rate.

I don't think we'll be seeing a 400+ hp genset in either hybrids or pure EV anytime soon except for sports models, just due to manufacturing costs. Would be fun though.

[rfkrfk]

24. I think I know why nobody uses supercaps

to take advantage of supercaps, having the ability to be charged fast,

you would need a huge electric motor,
which would be its own issue of,
cost, weight, and size

[skids]

25. Yeah I guess the bat C and generator power...

...are pretty much inextricably linked. One is sized for the other plus or minus. I think supercaps might still be useful for accel from a stop, if the performance justified a motor that could handle a brief oversurge. I wouldn't be surprised to eventually see a layered battery -- supercap fronting Li-ion fronting NiMH or vanadium redox, though. They are probably holding to a KISS philosophy for now.

[trekbiker]

26. some things to consider...

right now regen braking is very inefficient. If you brake with a decelleration greater than about 1mph per sec the energy is wasted as heat in the break pads and rotors. the problem is you cannot pump the energy into the Nimh batteries fast enough to allow for efficient regen braking. The new Li Ion battery technology has a much better energy density (allowing for greater amp-hours per unit of wieght) and new developments using nanotechnology are greatly improving the recharge rate which will allow for much greater efficiencies in regen braking. Present Prius owners have become expert in milking the brakes, slowing down well in advance of a stop sign, etc., in order to maximize efficiency and mileage. With the new technology they may be able to capture much more braking energy at greater decellerations. Also, battery pack voltages and capacities are likely to go much higher in order to make true PHEV viable. the generation 2 Prius will only make it about 2 miles on batteries only. True PHEV needs a battery capable of 30 to 40 miles at 45mph+. Plugging in over night would be required to take advantage of this. But with recharge rates of 90% in only a couple minutes for the new Li Ion technology this could really make PHEV viable. I can see a 100+ mpg Toyota prius PHEV running on some gasoline/ethanol mix in 5 years as being entirely possible.