Not good for Toyota if they are hoping to create a plug in hybrid:

Link (http://blogs.cars.com/kickingtires/2008/05/hybrid-accelera.html)

Not good for Toyota if they are hoping to create a plug in hybrid:

Link (http://blogs.cars.com/kickingtires/2008/05/hybrid-accelera.html)

...after 160,000 miles.

And you get 150,000 mile warranty on it in California & East Coast, 100,000 for the rest of the world. If your curious it is $2895 to replace the battery pack (actually 14 smaller batteries in a pack).


What's the expected failure range for the Volt? 150,000
Is Gm going to give out a 150,000 mile warranty on their pack? Maybe...but maybe not
What is the cost to replace out the pack at your local Chevy dealership? Hrm...scary as heck.

/nothing last forever

...after 160,000 miles.

And you get 150,000 mile warranty on it in California & East Coast, 100,000 for the rest of the world. If your curious it is $2895 to replace the battery pack (actually 14 smaller batteries in a pack).


What's the expected failure range for the Volt? 150,000
Is Gm going to give out a 150,000 mile warranty on their pack? Maybe...but maybe not
What is the cost to replace out the pack at your local Chevy dealership? Hrm...scary as heck.

/nothing last forever

Statik,

The Prius battery pack doesn't suddenly drop from 100% to 39% of capacity at mile mark 150,001. More likely, it follows a logorithmic decay, so it probably loses a significant amount of its capacity quickly and levels off towards the 61% decrease. It is disappointing that the government study didn't give numbers for battery capacity at various points along the way, but I wouldn't be surprised if those NiMH's had lost 50% of capacity after 50,000 miles. This tells us why Toyota wasn't able to respond immediately with an alternative to GM's introduction of the Volt. Toyota simply didn't have a battery tech that could hold its capacity for very long.

Also, GM is only expecting a 15% degradation in capacity after 150,000 miles, not 61%, so don't even try to make a comparison.

If all GM has to do at 150,000 miles is replace a battery pack to double the vehicle's life, that is a bargain.

All Prius testing was done on 'first gen US Prius' (2000-2002), which has a different pack than the current, which is also not the pack in the new Prius or the Plug-in (obviously). You are comparing 10 year old tech to future 'on paper' tech.


The Prius and the EV-1 where out at the same time. The Prius hit the market featuring the NiMH in 1997, with a smaller upgraded pack in late 99.

GM is so much better at battery tech than Toyota, they decided to feature lead acid batteries at the same time as the Prius. Hows the performance on one of those after like, 10K or 25K miles? I know what it is at 100 -- 0%.

They did manange to spit out 200 with a NiMH (after not being able to figure out how to retrofit them in for 6 months) a couple years later, (and after the lead ones where catching fire because of the charge port).

Then they decided to scrap them all and crumple them into little balls...kinda hard to long term test those. I'm sure they did it because they were so perfect at it they wanted to horde all the technology to themselves until the Volt came to market 13 years later.

"Not good for Toyota if they are hoping to create a plug in hybrid"-- clearly they shouldn't be as the battery pack they developed in 1998 demonstrates their lack of understanding in 2011...and GM is clearly a innovater in battery tech.

I'll let you have the last word, because I know copitulation is impossible on the internet.

GM did learn their lesson on the EV1, as they opted to bypass both lead-acid and NiMH for a Li-Ion chemistry that doesn't catch fire.

We are not talking about GM here. We are talking about Toyota's dead-end approach of a parallel hybrid vehicle with NiMH batteries that doesn't allow a simple path to becoming a plug-in hybrid with significant all electric range and performance.

The point is that Toyota could easily add a plug-in capability to their existing Prius's, but then everyone would see that it's charge capacity nosedives with use.

There's still quite a few Rav4-EVs in daily use. If Toyota had serious problems with battery life, it would affect those vehicles most severely (they would lose much of their range). I occasionally check in at EVNut.com and the Rav4-EV community seems perfectly happy with their cars. I expect Statik is right - the older Prius uses an older battery.

However, humoring Hendler and presuming that NiMH battery life is an issue, the HSD design turns out to be a stroke of genius as the bottom line on the Prius the government tested is that, after losing a significant chunk of battery life, fuel economy is almost identical with the vehicle when new.

GM is going to have its hands full fending off the Prius. Toyota can get the same battery technology as GM, whenever it's ready, and they are ready with the wheels, body and drivetrain. HSD is very flexible, if you want a verhicle that has different performance/range/economy characteristics, you can just change the size of the battery, engine (in addition to the 1.5 and 2.4, the 1.8 debuts in the Fall) or electric motor (and add a plug, if conditions warrant).

The battery is an issue for GM and only for GM because GM promised a car with characteristics that could not be satisfied by any existing battery. For HSD, incremental changess can be applied and with little risk.

However, humoring Hendler and presuming that NiMH battery life is an issue, the HSD design turns out to be a stroke of genius as the bottom line on the Prius the government tested is that, after losing a significant chunk of battery life, fuel economy is almost identical with the vehicle when new.

Dude, you are too damn funny. How is it genius that the complete collapse of the batteries ends up having no impact on the vehicle's performance?

As Bill Maher stated, the Prius gets good mileage mostly because it is just a small, low-performance car. The lack of an effect of the batteries having 39% capacity must mean either:

1) the regenerative braking system and low speed all electric range doesn't contribute much to gas mileage

2) Toyota KNEW NiMH battery capacity severely degrades, so they designed in more than 2.5X the batteries required

3) all of the above

What this reveals, is why Toyota CAN'T turn the Prius into a plug-in, all electric highway speed vehicle. The contribution of the electric systems is now very suspect.

It is engineering genius to build a car that allows for the degradation of the part and still operates the way the customer expects it to operate.

They still got a hybrid car out ahead of everybody else (including Honda, in JDM) with remarkable fuel economy that doesn't degrade.

Bill Maher is wrong; the Prius' fuel economy is remarkable, even considering the size of the car. The closest competitor is probably Toyota's own Yaris, which is considerably smaller, inside and out, and still doesn't come withing 20% of the Prius' highway economy or 30% of the Prius' city economy.

And, if they feel that they've tapped out the capability of NiMH, Toyota can still buy any battery they like today or whenever the one they like becomes available, to get the Prius to perform better. That is why Toyota CAN turn the Prius into a plug-in vehicle that hits highway speed on electric. They may not build a Prius with the EV range of the Volt but if it has 20 miles, who's to say no one will want that? 20 miles would take care of most of my driving.

And the current NiMH is probably far better than the 1997 battery, anyway, and it's likely the one in use by all the happy Rav4-EV owners. Remember them?

There's what should be a humbling thought for GM... the best EV on the road today is a 2001 Toyota Rav4-EV.

It is engineering genius to build a car that allows for the degradation of the part and still operates the way the customer expects it to operate.

I understand the concept of a failsafe vehicle with a "limp-home mode", but this is indicative of a much more serious problem - there was NO performance difference when 61% of the battery capacity was gone.


They still got a hybrid car out ahead of everybody else (including Honda, in JDM) with remarkable fuel economy that doesn't degrade.

If the performance doesn't degrade, then adding additional batteries to this configuration won't make it improve.


Bill Maher is wrong; the Prius' fuel economy is remarkable, even considering the size of the car. The closest competitor is probably Toyota's own Yaris, which is considerably smaller, inside and out, and still doesn't come withing 20% of the Prius' highway economy or 30% of the Prius' city economy.

I suspect that the Toyota's range is the result of using an engine that uses the Atkinson cycle - very efficient, like a normal 2 stroke - great efficiency, so-so performance. I still suspect their EV components aren't doing much.


And, if they feel that they've tapped out the capability of NiMH, Toyota can still buy any battery they like today or whenever the one they like becomes available, to get the Prius to perform better. That is why Toyota CAN turn the Prius into a plug-in vehicle that hits highway speed on electric. They may not build a Prius with the EV range of the Volt but if it has 20 miles, who's to say no one will want that? 20 miles would take care of most of my driving.

As I stated above, if degraded batteries don't hurt the performance, then more batteries aren't going to help. Something else is at work here. Their current config goes a mile or two below 30 mph, so it is a system design problem, not a component problem.


And the current NiMH is probably far better than the 1997 battery, anyway, and it's likely the one in use by all the happy Rav4-EV owners. Remember them?

There's what should be a humbling thought for GM... the best EV on the road today is a 2001 Toyota Rav4-EV.

Yes, NiMH's are getting better, but I suspect that the Prius parallel hybrid design is not. You can't slap more batteries into that thing and suddenly go highway speeds for 20+ miles.

I am starting to think that the EV components on the Prius are just props around an Atkinson Cycle engine that was otherwise too poor performing for American's to buy. I think the EV components may simply move a little energy around to improve the performance of an extremely efficient ICE, without truly increasing mileage themselves.

http://en.wikipedia.org/wiki/Atkinson_cycle

I think the Prius is an excellent design and has given the rest of the world confidence that 1) HEVs work and 2) People will buy them in large volumes. The Prius will go down in history as a game changer. End of story.

New story is that the new Prius plug-in will use lithium-ion battery technology. Japan has the most active lithium-ion battery research and development in the world:

http://www.bloomberg.com/apps/news?pid=20601101&sid=aCHIecOjRDRs&refer=japan

http://www.industryweek.com/ReadArticle.aspx?ArticleID=14123

http://findarticles.com/p/articles/mi_m0EIN/is_2002_Oct_3/ai_92383699


If you count out Toyota as a worthy competitor in the new electrified world you do so at your own peril. Besides, we want Toyota to come out with electrified cars that compete well with GMs cars. This keeps managers and engineers at both companies working hard and motivates them to keep the channels filled with high quality product in an attempt to be the market leader. This has the effect of keeping the prices down. Win-win for everyone... Even the car companies. When companies are working hard to advance their technology it keeps them in a great position to compete with newer, younger market entries. I'm cheering for all manufactures of electrified vehicles.

I think the Prius is an excellent design and has given the rest of the world confidence that 1) HEVs work and 2) People will buy them in large volumes. The Prius will go down in history as a game changer.

Fair enough.


End of story.

Not by a long shot.


New story is that the new Prius plug-in will use lithium-ion battery technology. Japan has the most active lithium-ion battery research and development in the world:

http://www.bloomberg.com/apps/news?pid=20601101&sid=aCHIecOjRDRs&refer=japan

http://www.industryweek.com/ReadArticle.aspx?ArticleID=14123

http://findarticles.com/p/articles/mi_m0EIN/is_2002_Oct_3/ai_92383699

I think you are missing the point of my previous posts. I don't think the battery tech has much to do with the excellent mileage of the Prius. I think it is 99% due to the highly efficient 2 stroke Atkinson cycle engine. Simply adding batteries to the current Prius system design will do little or nothing to improve mileage - their parallel hybrid scheme won't give you very good all electric range / performance.


If you count out Toyota as a worthy competitor in the new electrified world you do so at your own peril. Besides, we want Toyota to come out with electrified cars that compete well with GMs cars. This keeps managers and engineers at both companies working hard and motivates them to keep the channels filled with high quality product in an attempt to be the market leader. This has the effect of keeping the prices down. Win-win for everyone... Even the car companies. When companies are working hard to advance their technology it keeps them in a great position to compete with newer, younger market entries. I'm cheering for all manufactures of electrified vehicles.

I agree with all that. All I am saying is now I understand why Toyota tried to throw turds at the Volt when the series hybrid approach was announced, because Toyota was caught flat footed. I do believe that Toyota is expert at high quality / low cost products, but I also know it takes them several years to get there. GM is way out in front of them on a series hybrid design. Per my other thread, GM is 2 years ahead of Ford.

I think it is 99% due to the highly efficient 2 stroke Atkinson cycle engine. Simply adding batteries to the current Prius system design will do little or nothing to improve mileage - their parallel hybrid scheme won't give you very good all electric range / performance.


I hope you are using hyperbole. There is a simple way of testing your assumption. Take out the battery and run the car using only it's mechanical transmission. I will bet the ranch that the performance will suffer more than 1 percent.

You can also test your second claim by checking the performance of a converted Prius. Due to the activities of Hymotion and others you should be able to contact plenty of owners with little trouble.

If you are strictly talking about the non-plug-in model then adding too much battery capacity is simply a waste of money and weight. The battery of a HEV is used to 1) store regen energy and 2) provide bursts of power. This is what allows an undersized ICE. If you don't have enough battery capacity for the the two points I mentioned you will suffer in performance of the vehicle. It's true that driving at 65 mgh on a highway with a car that has very good aerodynamics (Prius) requires a very small ICE (around 20 hp). However, If you want to pass someone or have good 0-60 times you need the electric motor with it's correctly sized battery to help out. I guess I don't really understand your arguments. The Prius is a design success. Are you claiming it is not? That it would have the same performance if it only used it's undersized ICE?

I hope you are using hyperbole. There is a simple way of testing your assumption. Take out the battery and run the car using only it's mechanical transmission. I will bet the ranch that the performance will suffer more than 1 percent.

You are right, taking out the batteries will kill the performance of the vehicle, so it appears that you don't need much battery capacity for regenerative braking / launch assist. This is totally insufficient from what's required for all-electric, highway speed driving.


You can also test your second claim by checking the performance of a converted Prius. Due to the activities of Hymotion and others you should be able to contact plenty of owners with little trouble.

That's exactly what I am wondering. It appears that the Li Ion pack from Hymotion will only allow you to drive ICE free under 25 mph and won't really enhance ICE assisted driving, except when you need a burst of passing speed on long trips where you haven't been breaking much.


If you are strictly talking about the non-plug-in model then adding too much battery capacity is simply a waste of money and weight. The battery of a HEV is used to 1) store regen energy and 2) provide bursts of power. This is what allows an undersized ICE. If you don't have enough battery capacity for the the two points I mentioned you will suffer in performance of the vehicle. It's true that driving at 65 mgh on a highway with a car that has very good aerodynamics (Prius) requires a very small ICE (around 20 hp). However, If you want to pass someone or have good 0-60 times you need the electric motor with it's correctly sized battery to help out. I guess I don't really understand your arguments. The Prius is a design success. Are you claiming it is not? That it would have the same performance if it only used it's undersized ICE?

The Prius is a successful design, but now I realize it is almost entirely the result of its Atkinson cycle engine, and little to with the regenerative breaking systems. That is why these "mild hybrid" approaches by GM only provide a couple of mpg's over their standard models.

As I've stated before, the Prius is not a vehicle off which Toyota can build a series hybrid vehicle. Toyota may indeed use the Atkinson cycle engine as a range extender, but they must now basically develop an EV from the ground up that can perform on the highway.

Jason M. Hendler wrote: I am starting to think that the EV components on the Prius are just props around an Atkinson Cycle engine...
Yes, there is a truth in it. Look at the Honda Insight. It used all kinds of mileage extending tricks: extensive use of aluminum and plastic (less than 2000 lbs), coda tronca wind-cheating shape, rear wheel skirt, small lean-burn gas engine, low rolling resistance tires... so much so that we do not know which is the major contributing factor for the 70+ mpg. Think of the electric power booster of parallel hybrid as green turbo. It does save gas. In the case of Prius I think the smallish Atkinson cycle engine and idling stop are the major gas saving factor even though it carries around the extra weight of battery pack and electric motor.

Texas, I agree with you. We should not sneeze at Toyota/Panasonic alliance. At least they have an enormous fund to pour into the R&D. Notice they have been suspiciously quiet about the Li-ion cells. Panasonic is one of the first companies that started manufacturing Li-ion cells for computer and cell phone use (1994). Its first Li-ion cell related patent was applied for in 1980.

As I've stated before, the Prius is not a vehicle off which Toyota can build a series hybrid vehicle. Toyota may indeed use the Atkinson cycle engine as a range extender, but they must now basically develop an EV from the ground up that can perform on the highway.

Lets explore this for a moment. It is my contention that the new plug-in Prius design will exceed the efficiency of the Volt design during highway driving (assuming the Prius uses the same basic parallel series hybrid design that it uses today)

Assumptions:
1) The Prius 3.0 is driving next to the Volt for more than 200 miles. This will bring both cars down to full battery depletion and thus we can evaluate the long-term highway driving condition.

2) One driver is in each vehicle with no baggage. Try to keep the situation close to the way Americans drive for most of the time.

3) The Prius electric motor will be improved from 32 mph for V2.0 to 62 mph for V3.0 (Toyota did not say exactly what the higher continuous speed will be but the rumor is 62 mph). Note: this will not make any difference in this calculation but I wanted to put this in because of false information posted prior that the current Prius could only achieve 25 mph in battery electric mode (Prius conversions run up to 32 before the ICE switches on).


I will use the argument that the inherent differences in drivetrain efficiencies can be used to approximate gasoline mileage performance.

Volt 1.0 drivetrain map - highway speeds using above assumptions:

ICE - generator - lithium-ion battery pack - AC motor controller - AC motor drive - mechanical linkages - wheels

.40 X .90 X .90 X .90 X .95 X .90 = 27.2% **Corrected on 20080514 - thanks hvacman**

Prius 3.0 drivetrain map - highway speeds using above assumptions:

ICE - Continuously Variable Transmission - mechanical linkages - wheels

.40 X .80 X .90 = 28.8%

People can argue the numbers and I welcome any corrections but I hope it's clear that when the battery is at 30% and can no longer provide energy to the wheels that the Volt's motor must run though the mechanical-to-electrical-to-mechanical cycle to keep the wheels running while the Prius will stay in mechanical mode. If the above situation were not the case we would have had low technology serial hybrid cars on the road for many decades. We already have trains and buses that have serial hybrid configurations. Trains use this because the electrical transmission is so powerful for it's weight and has maximum torque at 0 mph and also huge locomotive mechanical transmissions are not as reliable as the simple electric motor. This lowers maintenance costs.

Of course we will have to wait until the two are compared and compared they will be. It will be a national obsession to see which car performs better. My prediction is that the Volt will out-perform in many ways in the city and in other situations but the Prius will win on the highways (assuming the coefficient of drag for the two vehicles are similar). Time will tell. I am hoping that the two companies (and others) will both have strong products that help the world move away from petroleum burning for personal transportation.

"As I've stated before, the Prius is not a vehicle off which Toyota can build a series hybrid vehicle." - Hendler

I'd have to care enough to go back and look but I don't believe you qualified that statement, previously, with "series" hybrid. And why would Toyota bother to build a series hybrid when HSD works, is becoming more inexpensive by the day and is field-proven?

The Prius with Hymotion is limited to 25mph EV because that's all the Prius will do on EV, the motor's not particularly big. But that's the current Prius. Remember, HSD allows you to change the ICE, the electric motor or the battery to suit your needs.

The next Prius, stock, due in MY 2009, will have the capability to do 100km/hr, on the EM only. Add the existing Hymotion to that (Toyota will do it at the factory, of course) and there's a short-range EV. When a bigger battery is available, there's a longer-range EV.

The Atkinson is a critical part of the equation. It's more efficient but it offers less power. HSD to the rescue; combine the ICE and EM when you need maximum power. Toyota could have brought the thing out with a regular Otto cycle but they didn't miss a trick, did they?

By the way, Hendler, you haven't explained how it is that all those Rav4-EV owners can remain happy with their vehicles if the battery degrades so dramatically. EV performance will certainly degrade with the battery, there's no relying on the ICE to take up the slack. Apparently, Toyota has learned a few new tricks since 1997.

As for Toyota throwing turds... at what? GM has no hybrid product which they successfully sell. Toyota sells 20K Priuses per month. As for GM being 2 years ahead of Ford... with what? Ford has product on the road, since 2005, with many satisfied customers. GM leads only in overpaid, underperforming execs and PR stunts.

Toyota salesman says stampede to Prius makes for the best of times

"Portland shoppers are flocking to the car with the best fuel efficiency Tuesday, May 13, 2008 STEVE WOODWARD The Oregonian Staff It is the best of times. For a Toyota Prius salesperson.

When customers walk into Ron Tonkin Toyota Scion on Southeast 122nd Avenue, the first question most ask salesman Mark Knudsen is: "What gets the best mileage?"

That's easy. It's the Prius, a hybrid electric-gasoline car that outsells all other hybrid cars in the United States combined.

The Prius gets about 46 miles per gallon -- 550 miles on a single tank of gas, which at Monday's AAA price estimate in the Portland area amounts to $44.28.

"I have only happy customers with Priuses," Knudsen declares.

Knudsen is happy, too. He's selling not only Priuses, but also other low-mileage cars such as Toyota's Yaris, Matrix and Camry.

Armed with degrees in architecture and history, plus 20 years in the food-and-beverage industry, Knudsen began selling Toyotas in 2000, just four months after the Prius was introduced to the United States.

"It's taken a while for the public to embrace the technology," he says.

But in the past couple of months, as oil and gasoline prices exploded like gushers, consumers are trading in their big cars, SUVs and trucks for gas sippers.

"We're seeing anybody driving a V-8," Knudsen says one recent evening during a lull in the action. "They're not very happy spending $100 filling up their car."

Josh Leader, the dealership's new-car sales manager, echoes other dealers in metropolitan Portland who say they can't keep Priuses in stock. The waiting list is three months long.

"Sales are going through the roof," Leader says, "and through the other roof that hasn't even been built yet."

At Gresham Toyota, Ken Hodgdon, the general sales manager, says sales have surged in the past 30 to 45 days.

"We're selling them as fast as they hit the ground," Hodgdon says of the dealership's monthly allotment of 25 to 30 Priuses.

Many gas-gulping trade-ins end up at auction houses, which sell ever-growing numbers of high-mileage vehicles to dealers for ever decreasing prices.

Knudsen, 47, a Northeast Portland car lover, owns a high-performance Toyota Supra, a model the company discontinued in 1999. But many prefer the status that Prius enjoys as an environmental icon.

Knudsen says the good news is that more Priuses are always on their way. The bad news is that they're usually sold before they're even unloaded.

"People have waited up to a year for this car," he says.

The bottleneck lies at Toyota's battery-making plants, which have been slow turning out batteries for the Prius and Toyota's other hybrids, Camry and Highlander. To make matters worse, every time gas prices rise, Knudsen says, more Prius shoppers make the pilgrimage to the dealership.

Knudsen can show them only one car on the lot: a silver demonstration car outfitted with a top-of-the-line package of accessories.

He's had several offers to buy the demo. It's not for sale"



http://www.oregonlive.com/living/oregonian/index.ssf?/base/living/1210634729129740.xml&coll=7

dagwood,

The point of a series hybrid is to drive without using ANY petroleum. A parallel hybrid still requires the use of petroleum. You only have to view GM's presentation to understand the impact on petroleum consumption between driving series and parallel hybrids:

GM Product Plan (http://fastlane.gmblogs.com/PDF/presentation-sm.pdf)

BTW, 62 mph isn't going to cut it for highway driving, when the speed limit is 65 / 70 mph and everyone else is driving 75+ mph.

Moreover, as you can see from GM's product plan, the series hybrid makes a simple stepping stone to the fuel cell vehicle, whereas the parallel hybrid vehicle does not.

Certainly, Toyota can create a series hybrid, they just can't use what they've done with the Prius, so they are starting from scratch.

As for why "RAV4-EV owners are so happy", I suspect it is because they own a RAV4-EV as a second car, and therefore aren't hamstrung by the limitations of a 125 range, which keeps falling, falling, falling ....

62mph will cut it fine when the speed limit is 55 to 60 mph and everyone is doing 0-20-0-20-0-20.

EV range keeps "falling, falling, falling..." Do you have one iota of evidence that Rav4-EV owners are experiencing noticeable degradation?

BTW, beautiful presentation. Now, all GM needs is a 50+mpg car to go with it.

One that sells.

62mph will cut it fine when the speed limit is 55 to 60 mph and everyone is doing 0-20-0-20-0-20.

EV range keeps "falling, falling, falling..." Do you have one iota of evidence that Rav4-EV owners are experiencing noticeable degradation?

BTW, beautiful presentation. Now, all GM needs is a 50+mpg car to go with it.

One that sells.

Yes, that presentation is a genius strategy from GM. Do you now see the significant difference in petroleum consumption between a parallel and series hybrid? The Prius isn't a bad design, it just isn't going to reduce petroleum consumption as much as the series hybrid.

I am confident that GM will succeed in producing the Volt on time and at a profit (production costs / not development costs).

Yes, I'd say that a GM presentation is definitive proof that the GM series hybrid approach is better.

Now, as long as the competition will just do things exactly the way GM says they will in their presentation and ensure that their cars stick to the performance characteristics GM assigned to them, the Volt will be a world-beater.

I hope Toyota, Honda, Nissan and Ford understand and fulfill their important role in ensuring th success of the Volt.

Yes, I'd say that a GM presentation is definitive proof that the GM series hybrid approach is better.

Now, as long as the competition will just do things exactly the way GM says they will in their presentation and ensure that their cars stick to the performance characteristics GM assigned to them, the Volt will be a world-beater.

I hope Toyota, Honda, Nissan and Ford understand and fulfill their important role in ensuring th success of the Volt.

... from your mouth to God's ear ...

Well, I guess since we don't have a Volt 1.0 or a Prius 3.0 to have a show-down I guess we have to listen to all kinds of mindless crap. Why use any numbers, energy concerns or the very basics of mechanical and electrical efficiencies. Let's keep our fingers tapping and our mouths flapping. Not like there's anything we can actually go out and buy... No wait.

Well, I guess since we don't have a Volt 1.0 or a Prius 3.0 to have a show-down I guess we have to listen to all kinds of mindless crap. Why use any numbers, energy concerns or the very basics of mechanical and electrical efficiencies. Let's keep our fingers tapping and our mouths flapping. Not like there's anything we can actually go out and buy... No wait.

You are correct. There is not a highway speed all electric mode hybrid on the road today.

You are correct. There is not a highway speed all electric mode hybrid on the road today.

Now you are starting to understand! There are none because it's more efficient to use a mechanical transmission. If you disagree, please go back to my previous post and tell me where my numbers don't jive. Insert some of your numbers or provide any calculations to the contrary. Anyone? I only wish to get the facts straight. If my numbers are so far off that the serial hybrid system at highway speeds is more efficient than I would be quite happy. I love the serial hybrid approach for many things but long drives on the highway is not on my list of advantages.

Now you are starting to understand! There are none because it's more efficient to use a mechanical transmission. If you disagree, please go back to my previous post and tell me where my numbers don't jive. Insert some of your numbers or provide any calculations to the contrary. Anyone? I only wish to get the facts straight. If my numbers are so far off that the serial hybrid system at highway speeds is more efficient than I would be quite happy. I love the serial hybrid approach for many things but long drives on the highway is not on my list of advantages.

GM has determined a way to drive on the freeway in all EV mode, and it will be on the road in 10's of months. People want to avoid petroleum use completely, not just "kick the can" of peak oil down the road.

Most people drive 40 miles per day, not 200 miles, so the series hybrid will meet the American buyers real needs, not imagined.

So you agree that the Prius will probably be more efficient after the batteries get to 30% on the highway?

If so, then we can talk about the sub 40 miles. Firstly, almost three years is a long time for things to change. Maybe Toyota will bump up the rumored (they never specified what their 3.0 drivetrain will be) 62 mph all-electric range to 70 mph. This would put the two cars on the same path depending on how much battery capacity they decide to put in. For many people driving 62 mph is more than enough. Maybe the government will make us drive 55 mph again. Very possible. My point is that we don't even know what the final specifications for the two cars will be when they finally debut in 2011 and you are arguing that the Prius' parallel series hybrid design is inferior. I just fail to see your logic. The Prius can and does run in pure series hybrid mode up to the limits of the electrical motor and battery pack. When it turns on the ICE it then very efficiently uses a mechanical drivetrain to power the wheels (while the electric motor assists when appropriate).

You can't see the customer's preference to drive using only the electricity from their home?

I like how, for your own argument, you upgrade Toyota's specs for its future vehicles. If we are playing that game, then I want to upgrade GM's range extender to something more efficient than Toyota's Atkinson cycle engine - that way, I win.

You can't see the customer's preference to drive using only the electricity from their home?

I like how, for your own argument, you upgrade Toyota's specs for its future vehicles. If we are playing that game, then I want to upgrade GM's range extender to something more efficient than Toyota's Atkinson cycle engine - that way, I win.

1) Where did I say that I don't or that the Prius 3.0 can't? I think Toyota has the best reputation for knowing what customers like when it comes to hybrids. Would I be wrong stating that?

2) Can you please direct me to the specifications that were introduced by Toyota for the Synergy Drive 3.0?

"I want to upgrade GM's range extender to something more efficient than Toyota's Atkinson cycle engine - that way, I win." - Hendler

You make me smile. I figure the odds of GM building "something more efficient than Toyota's Atkinson cycle engine" are somewhere between slim and none.

"You can't see the customer's preference to drive using only the electricity from their home?" - Hendler

No. From the customer perspective, the criteria are likely to be, "Price, comfort, price, features, price, fuel economy." And, maybe, price.

There are a few True Believers that will want a Volt at any price and a few more people that that will prefer a Volt at a reasonable price but consumers who care about issues like global warming and strategic dependence on imported oil will consider "very good fuel economy" to be good enough and the majority will only care about price. Which explains why SUVs still outsell cars like the Prius.

There are a few True Believers that will want a Volt at any price and a few more people that that will prefer a Volt at a reasonable price but consumers who care about issues like global warming and strategic dependence on imported oil will consider "very good fuel economy" to be good enough and the majority will only care about price. Which explains why SUVs still outsell cars like the Prius.

You lost me here. So...what do the SUV owners care about?

Features and creature comforts. Certainly not imported oil or global warming.

Just a little fine-tuning to the efficiency debate. At constant freeway speeds, with batteries depleted, the mechanical transmission links of the parallel hybrid will be more efficient than a series hybrid, but it isn't as bad as presented. Most of the Volt ICE-generator power will probably NOT pass through the battery charger and batteries first, as the charger is only rated at about 3.5 kW and the generator is about 53 KW. I'm assuming most of the power will directly go to the 300 VDC bus feeding the motor variable-frequency drive controller. The efficiency therefore is ICE x generator x VFD x motor x mech. linkage = .4 x .9 x .95 x .90 x .90 = 27.7%. I also noticed that the "wheel" efficiency losses were plugged into Texas' calcs for the series hybrid, but not the parallel, so I deducted that one from my calc. The comparison - 27.7% vx 28.8% on an apples-apples basis.

With the mechanical simplifications of fewer mechanical parts, better around-town mileage characteristics, and that "all-electric" buzz that defies economics, I still think the Volt will be a winner and Toyota may have outsmarted themselves on this one. It will be an interesting time come 2010 to see how this plays out.

I agree with HVACMAN's analysis, but would like to add that a 40% - 40% for both ICE's is too simplistic. Over steady highway sppeds this may be accurate, but theoretically over variable loads the Volt can have the edge or pull equivalent (at least if they Volt's ICE is optimized for 2 or 3 levels of output as mentioned at Voltnation). The Volt is expected to use the battery for most load variations and keep the ICE as steady as possibly at it's sweet spot. The Prius, if basically scaled up for plug-in and more capable motor but still being primarily a blended mode vehicle, will rely on the ICE for much of the load variation.

I will use the argument that the inherent differences in drivetrain efficiencies can be used to approximate gasoline mileage performance.

Volt 1.0 drivetrain map - highway speeds using above assumptions:

ICE - generator - lithium-ion battery pack - AC motor controller - AC motor drive - mechanical linkages - wheels

.40 X .90 X .90 X .90 X .95 X .90 X .90 = 22.4%

Prius 3.0 drivetrain map - highway speeds using above assumptions:

ICE - Continuously Variable Transmission - mechanical linkages - wheels

.40 X .80 X .90 = 28.8%

People can argue the numbers and I welcome any corrections but ...

Good thought provoking post…and since no one is commenting on your efficiency assumptions, allow me. For the Volt in charge sustaining mode, your efficiency assumptions were:

ICE (.40)
X Generator (.90)
X Lith Ion Batteries (.90)
X AC motor controller (.90)
X AC motor Drive (.95)
X Mechanical Linkages (.90)
X Wheels (.90)

.40 X .90 X .90 X .90 X .95 X .90 X .90 = 22.4%

Not having the first clue if these are realistic estimates or not (they looked reasonable to me) I did some quick research to see if I could find any efficiency values. Based on what I found at http://auto.howstuffworks.com/fuel-cell4.htm (http://auto.howstuffworks.com/fuel-cell4.htm) , your estimates for EV efficiency may be a tad low.

How Stuff Works gives EV efficiency at 72%. They also quote a charging system efficiency of 90%.

Being the anal retentive type, I calculated your estimate for EV efficiency to see how it compared. I came up with the following: (.9 X .9 X .95 X .9 X .9) = .623 or 62.3%.

(I USED THE BOLD NUMBERS IN YOUR CALCULATION ABOVE)

You are in the same ball park, 62% verses 72%. Is their EV Efficiency Estimate more accurate than yours? I haven’t a clue, but I did find some NEMA Minimum Nominal Efficiency numbers for electric motors. NEMA specifies a minimum efficiency of 92.4% for a 125+ HP electric motor, so I would image the electric motor in the Volt will meet and hopefully exceed this value.

Thus, assuming an EV efficiency value of 72% in place of your estimate of 62%, and also adding in their estimate for charging efficiency (I believe this is what you are calling Lith Ion Batteries), I calculate a Volt 1.0 has a potential charge sustaining mode efficiency of:

Efficiency ICE (.40)
X Generator Efficiency = (.90)
X Charging Efficiency = (.90)
X EV Efficiency = (.72)
= 23.3% -- which is a tad higher, but very close to your original estimate.

Taking a closer look at your Prius 3.0 calculation, it appears you left off wheel efficiency (friction) – so doing the math again I calculate the following efficiency for the Prius 3.0

ICE Eff (.40)
X Continuously Variable Transmission Eff (.80)
X mechanical linkages Eff (.90)
X wheel friction (.90)
.40 X .80 X .90 X .90 = 25.9%

Thus the two vehicles are a little closer in overall vehicle efficiency by this estimate, 23% vs 26%. So until we have the real numbers, my take away is it is just too close to call at this point…too many unknowns. Change a percentage here and there, and the results will change.


Gasoline and Battery Power Efficiency

http://auto.howstuffworks.com/fuel-cell4.htm

The efficiency of a gasoline-powered car is surprisingly low. All of the heat that comes out as exhaust or goes into the radiator is wasted energy. The engine also uses a lot of energy turning the various pumps, fans and generators that keep it going. So the overall efficiency of an automotive gas engine is about 20 percent. That is, only about 20 percent of the thermal-energy content of the gasoline is converted into mechanical work.

A battery-powered electric car has a fairly high efficiency. The battery is about 90-percent efficient (most batteries generate some heat, or require heating), and the electric motor/inverter is about 80-percent efficient. This gives an overall efficiency of about 72 percent.

But that is not the whole story. The electricity used to power the car had to be generated somewhere. If it was generated at a power plant that used a combustion process (rather than nuclear, hydroelectric, solar or wind), then only about 40 percent of the fuel required by the power plant was converted into electricity. The process of charging the car requires the conversion of alternating current (AC) power to direct current (DC) power. This process has an efficiency of about 90 percent.

So, if we look at the whole cycle, the efficiency of an electric car is 72 percent for the car, 40 percent for the power plant and 90 percent for charging the car. That gives an overall efficiency of 26 percent. The overall efficiency varies considerably depending on what sort of power plant is used. If the electricity for the car is generated by a hydroelectric plant for instance, then it is basically free (we didn't burn any fuel to generate it), and the efficiency of the electric car is about 65 percent.

Koz,

You know, I considered bringing up the possible efficiency gains from the increased engine speed and load flexibility of the ICE-generator combination, but figured it would be tough to document. Toyota's CVT also gives their ICE a lot of flexibility to optimize speed/power combinations.

The Toyota hybrid tranmissions are very creative and well-built machinery. With further maturity, it will offer a great energy-efficient alternative for plug-in hybrids.

That said, I've been designing mechancial systems that use large HP pumps and fans for 30 years. 30 years ago, we dealt iwth our variable speed drive requirements with hydraulic, belt, and and mechanical drive transmission drive systems.

The explosion of low-cost, high efficiency power electronics has now made all those obsolete. Electric motors with variable frequency drive controllers handle everything. They have no belts to break, no gears to oil, no clutches to wear out. Just two bearings and a lot of solid state components. Their net efficiencies rival their best mechanical replacements, are infinitely programmable through digital controllers, and can run for 20,000 hours or more between services. Try that with any mechanical tranmission.

The Volt brings the automobile into the 21st century for drive transmissions. Toyota's configuration, though very impressive, could be the last of the mechanical breed. Kind of like the great log-log slide rule K and E released in the late 60's, just before HP released the HP 35 and 45 calculators and made engineering slide rules forever obsolete.

I also noticed that the "wheel" efficiency losses were plugged into Texas' calcs for the series hybrid, but not the parallel, so I deducted that one from my calc.

Thanks hvacman. I made a mistake by adding an extra .90 percent on the Volt. I corrected and dated the changes to the post.

Rooster, thanks for going deeper into the efficiencies. As a few of you have been pointing out the efficiencies are (or can be) quite close to the point where we will need to have both on dynos to see what system is more efficient. I look forward to the comparison wars. This is the best way we can figure out the advantages and disadvantages for each type of system. When combined with all other variables like overall cost, individual travel routines, risk parameters, etc. The consumer will be able to make a more informed decision based on their unique situation. Better educated consumers are better for the industry. It forces manufacturers to keep an eye on the details. The days of, "I bought it because it had a pretty two-tone paint job." are long gone, I hope.

hvacman, You brought up something that concerned me. Are you sure that the Volt's ICE is only connected to the battery pack with a tiny 3.5 kW power supply? If so I'm completely shocked by this. If true the battery pack could essentially be pulled out of the Volt and it would run fine with diminished performance. A tiny 3.5 kW supply of power is only the equivalent of three hair driers going at once. The generator would then take 4.6 hours to charge the battery at maximum charge rate. Using the Volt as a backup generator just became more difficult. I was counting on just attaching a AC inverter to the 300 VDC battery terminals. If the battery can only be fed at 3.5 kW then... What about the regen system? That must surely have more than a 3.5 kW capability into the battery pack.

I will need to see the final electrical schematics to figure out how they are going to do this and if the efficiency of the system can be held to what we have assumed. If the battery is taken out-of-the-loop there will probably need to be some power conditioning circuits in-between the generator and the AC motor controller. I was assuming the battery would act as the main capacitor smoothing out the fluctuations in power delivery and providing the needed energy for instantaneous burst power. Anyway, maybe our resident power electronics engineer Joshua will chime in.

Great discussion! Hey GM, when can we get a copy of the electrical schematics? ;) Might want to include everything including all of the control electronics. Heck, would asking for all the software be too much? lol. I'm guessing there will be all kinds of clubs that will be looking to make major modifications to the Volt. Pure BEV, new updated battery packs, Quick-charge capability, performance modifications. You name it. It's a whole new age where electrical, computer, and mechanical guys will all be eager to get in on car mods. If you think of it changing out the drive motor for one that is twice (or more) as powerful and installing a new high power battery pack is not that big of a deal. Hummmm. Mean and Green.

The Volt brings the automobile into the 21st century for drive transmissions. Toyota's configuration, though very impressive, could be the last of the mechanical breed. Kind of like the great log-log slide rule K and E released in the late 60's, just before HP released the HP 35 and 45 calculators and made engineering slide rules forever obsolete.

... which brings me back to my point that the Prius is not a baseline design (motor / drivetrain) that Toyota can use to develop a series hybrid. Toyota now has to develop a purely motor driven drivetrain, battery pack (supplier), range-extender and all the control systems to make them all work together in an automotive application.

hvacman, You brought up something that concerned me. Are you sure that the Volt's ICE is only connected to the battery pack with a tiny 3.5 kW power supply?
Actually, I haven't a clue of how the ICE-generator will be connected to the batteries, but assumed it would use the same circuitry as the plug-in charger. There is all sorts of voltage/amp regulation required during the charging cycle and I can't picture GM duplicating that circuitry for a separate generator-connected charger device. The primary purpose of the ICE-generator is not to re-charge the batteries, but to feed the 150 HP motor when the battery pack is depleted. The plug-in charger, at 230 volts AC, will be a 15 amp charger, which means about 3.5 kW. I'm not sure how fast these LI batteries can take a charge. The total amp-hour capacity will only be about 50 A-H. How fast can you charge a 50 A-H lead-acid battery? Usually, you can only feed in about 10-12 amps before overloading the plates, heating up the battery, and just wasting energy. I suspect we won't get much faster charging rates until the next generation of batteries which will have "quick charge" capabilities.

Remember that the batteries float between 30% and 80%, so that is just 8 kWh, or about 26 A-H to re-charge. At 13 amps, that's about 2 hours to re-charge the batteries to a pretty decent level.

I found a great series hybrid system schematic from the Lombardini guys. Sorry but you have to first go to generators then to engine families then to the new projects section and then click on ECOMove. Just scroll down the page and you are there(I don't know why it's so hard to get to this section). It shows the full output of the generator is inputted into the power controller. The motor controller and the battery are directly connected off the same line. Judging from the charging capacity of Valence's new batteries (they can take quite a lot of charge) I would think A123's could take much more than 3.5 kW. I sure hope so. Anyway we can start from this and go from there:

http://www.lombardinigroup.it/starter.php?lang=2

great find, Texas. First actual power schematic I've seen for a series hybrid.

It looks like the "power controller" may be a rectifier/DC voltage controller, as the generator may be an AC alternator without built-in diodes. This controller would probably also handle AC input from the plug-in. If the batteries are just floating on the DC bus, then the amount of charging current will be regulated by the difference between the battery voltage and the bus voltage, which the power controller will be carefully monitoring and controlling. That's the $$$ question that will determine just how fast those batteries charge.

Not good for Toyota if they are hoping to create a plug in hybrid:
One should keep in mind this was EOL testing for so-called Generation One (NHW11) Priuses. [Technically, it was Generation Two since the true Generation One Prius (NHW10) was sold in Japan and imported to the UK, Australia and New Zealand.]

Twould be very interesting to see EOL testing on HSD Priuses.

As for why "RAV4-EV owners are so happy", I suspect it is because they own a RAV4-EV as a second car, and therefore aren't hamstrung by the limitations of a 125 range, which keeps falling, falling, falling ....
Anecdotally, RAV4 EV owners aren't experiencing this degradation.
http://www.evnut.com/rav_owner_gallery.htm

Not even the 100K club.
http://www.evnut.com/rav_owner_100k.htm

This old thread was an interesting argument. Just to clear up a few inaccuracies: The second generation Prius does not have to start the ICE aboce 32. I have driven several miles on level road at 40+ MPH on battery only. "The battery of a HEV is used to 1) store regen energy and 2) provide bursts of power." excludes that also provides ample additional torque (not just bursts). The original posts really seem to downplay the capacity of the Prius battery to drive the car. The original posts and the subject of this thread was about the batteries losing 61% of their capacity. I would argue, from experience, that the report of Prius batteries' demise are greatly exaggerated.

Prius owners are, in fact, very happy with their cars. They have been great cars. They are roomy, have lots of cargo capacity, are nearly flawless (OK, at 150K we had to replace the windshield wiper actuator, at 170K and 5 years the 12V battery, and at 190K the front wheel bearing/hub assemblies...), and give outstanding fuel economy. We even have a trailer hitch to pull our jetski or RIB.

Don't get me wrong - we love our Volt! What an awesome car. But that doesn't take anything away from the Prius Hybrid - it is still a great vehicle in its own right. I would argue that Prius owners represent one of the biggest potential markets for the Volt. The Volt is the next logical step for the Prius owner. Prius owners already appreciate the hybrid model, and are already experienced at efficient driving style. For us, the Volt was a natural fit. Makes me wonder why Volt enthusiasts think it is necessary to disparage the Prius...

There have been a fair share of Prius owners taking shots at the Volt and vice versa. There will always be a certain amount of intramural cross-town rivalry I suppose. I have nothing against the Prius. Had there not been a Volt, or if I had a very long commute, I would have seriously considered a Prius.

IMO, I have seen little disparaging of the Prius on this forum. Other than when we used to frequently battle the two chief Prius prognosticators from Priuschat (you know how they are), that has changed since the Volt came out. As a previous owner of a Toyota and a Lexus, I agree that they make very good cars.

Although we evangelize the Volt, we don't have to belittle the competition. In fact I wouldn't mind getting a Tesla in a few years.

Makes me wonder why Volt enthusiasts think it is necessary to disparage the Prius...I think the only poster in this thread (before you posted) who has ever owned a Volt was statik, and he was arguing that the Prius batteries weren't a problem.

Most people would agree that the Prius is very reliable and holds a lot of stuff and gets great MPG. Most would also agree that the batteries aren't a problem. That said, as a car it's sort of the ultimate "no-fun" machine and the tech is no longer cutting edge, though if you need a bigger vehicle the V is worth a look.

IMO Pretty damn good if you had to go 3 years back in time to locate a thread where the Prius was discussed negatively or disparaged.
We just dont do that here.
We have much better things to do...
WOT
This old thread was an interesting argument. Just to clear up a few inaccuracies: The second generation Prius does not have to start the ICE aboce 32. I have driven several miles on level road at 40+ MPH on battery only. "The battery of a HEV is used to 1) store regen energy and 2) provide bursts of power." excludes that also provides ample additional torque (not just bursts). The original posts really seem to downplay the capacity of the Prius battery to drive the car. The original posts and the subject of this thread was about the batteries losing 61% of their capacity. I would argue, from experience, that the report of Prius batteries' demise are greatly exaggerated.

Prius owners are, in fact, very happy with their cars. They have been great cars. They are roomy, have lots of cargo capacity, are nearly flawless (OK, at 150K we had to replace the windshield wiper actuator, at 170K and 5 years the 12V battery, and at 190K the front wheel bearing/hub assemblies...), and give outstanding fuel economy. We even have a trailer hitch to pull our jetski or RIB.

Don't get me wrong - we love our Volt! What an awesome car. But that doesn't take anything away from the Prius Hybrid - it is still a great vehicle in its own right. I would argue that Prius owners represent one of the biggest potential markets for the Volt. The Volt is the next logical step for the Prius owner. Prius owners already appreciate the hybrid model, and are already experienced at efficient driving style. For us, the Volt was a natural fit. Makes me wonder why Volt enthusiasts think it is necessary to disparage the Prius...

IMO, I have seen little disparaging of the Prius on this forum. Other than when we used to frequently battle the two chief Prius prognosticators from Priuschat (you know how they are)
I've been debating them there so we don't have to debate them here. :-)