IL Corrects Volt Story: Batteries Will NOT Charge When Driving; GM Website Differs

[AMERICA 123]

Originally Posted by fan

Running the e motors by the gas engine through a generator, would limit stress on the battery.

When battery is depleted and the car is running, the energy delivered by the gas engine to the battery would instantly be transferred from the battery to the electric motors.

It would be an even more undesired path than engine-generator-wheels.

It would actually be engine-generator-battery-wheels.

Since battery is expensive and its life cycle is the main issue with it, avoiding transferring a part of the energy through it when there is an

acceptable alternative (gas engine-generator-e motors) could be a positive thing.

You are correct.

Unless and apparently so....'some things' 'changed' - and / or they hit a big constraint.

There would be plenty of power available - any number of 'ways'.

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The history of Diesel / Electric propulsion systems on submarines shows us some things useful here.

The developed preference was until noise reduction requirements took precedence, strongly for what you state - and for why you state.

They had 'two' main 'configurations' they ran in - outside of all electric - that were met in one of several ways - depending on how the boat

was built.

With the diesel in - battery charging/ w/wo forward propulsion, and the now relatively less frequent 'trickle charge' with 'movement'.

Not all were built the same and later ones have other requirements to meet that change things up - especially the later still non nuc, non diesel/

battery - we can usefully skip those - as well as some other..

Some technically could have / can be run in some combination of three ways ie diesel - direct, diesel - generator - electric motor and a diesel-

battery - gen- electric motor - although not necessarily providing the same options on all shafts.

When other 'requirements' do not take preference, they avoid the battery - whether charging or not - using the most direct 'method' on board.

**********************

On this one ( the Volt ) , an occasional assist from the battery would round it out nicely - along with the obviously desirable ' regen ' ie 'electric' back and forth'.

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You really maybe on to something with your other - great job all around thinking it thru.

[Hybridized]

Heh, now that I have read this thread and thought about it a bit, I offer up yet another opinion
I think of three battery phases, as a function of SOC:

1 35 - 85: EV mode, or blended with ICE for high power demands
2. 35 - 30.x: CS mode with ICE on powering car and sending juice to battery. Battery assist available. Unclear to me what happens in low power demand here. It would make sense for ICE to run higher than operator demand in an efficient power-band, but I'm only guessing on this point.
3. =< 30: ICE only, battery recharging when car power demands allow it.

Phase 3, just like in a Prius, is unusual but certainly happens. The more aggressive the driver and more hilly the terrain, the more likely it is to come into effect.

[AMERICA 123]

Originally Posted by Hybridized

Huh.
Back to my original point: the Volt is not a choice for the price conscious consumer. And now let's return to the thread, OK ?

Depends how you look at it - for sure it will more than give any Prius built way more than a run for the money.

Clearly it will completely dominate the value equation - if you own a Pri you'll want one.

There will also most likely be some considerable sort of price overlap - when we get there - what approx. two years from now ?.

Btw, how about using current Prius pricing and trying to honestly add for the inevitable prices increase that will occur by the time the

Volt gets here - like the one already announced on the 2009s ?

Did I miss it, or did you forget to describe your model year? - because you definitely did in the biggest post you made about its price.

Also, given how you post, besides all the above, you forgot to mention a few things - like the now humongous regional pricing differences and

choices - and that the 11 - 12 % plus ?? going into fleet sales are from the lower end - meaning the retail customer base numbers are higher.

Tell me, since it appears we have so many on the end of the pier fishin' for something, why the sudden advertorial negativity towards the Volt ?

Are they nervous that its going to impact both the Prius models - and the Lexus derivative ?

I know, the numbers and statements are so confusing - so many to choose from.

If so, let me help you out.

You don't have to worry about the Prius PHEV - because practically speaking it won't really exist by then - unless you count 100 to 300 available

to specially selected fleets as a retail sales effort in the US.

[MonaroSS]

Originally Posted by big swede

Let's get real. We are not debating GM's exact settings they are going to use on the production model. There are so many settings to be determined just in the fact of when and how much charging should take place and under a myriad of variable scenarios that I'm pretty sure exact settings are still being worked on and will probably be tweaked on a yearly basis through PCM updates.

The biggest difference you have with GoBlue and I is that you say the Volt will work in a diminished capacity after the 40 miles on battery. That's really the main disagreement I have with you. And no I won't call you the names you called me I will just say we agree to disagree.

Not so fast. Details count.

For instance, you said, "I'm actually surprised the ICE would charge it as high as 85%", but in fact so would I as the ICE never recharges the battery. That cycling rate relates to the charge/discharge cycle from plugging it into the mains power.

BTW, for people who talk about having a charge point at work, I will point out that GM in it's instructions to owners would discourage you plugging in at work unless you are close to depleting the battery reserves. The Volt is designed for people who commute LESS than 40 miles per day and if a little more then they can use some gasoline. But the ten year life expectancy of the battery is loosely based upon 1 cycle per day. If your recharge it at night and at work for 2 cycles per day then expect to shell out $10K for a new battery 5 years earlier.

BTW, GM has also spoken of the ICE running at up to three discrete rpm’s with phasing between them so as to smooth out the sound for occupants.

Also, Larry Nitz said they were able to raise the cycle points from 30-80 to 35-85, but able to dip down into the 30+ range. Add to that he said the engine at 50kW (67hp) "does not have the full power to do the dynamic response [but] that the electric side can, so you do have to depend on the battery". So you can probably conclude the meaning of what Lutz said about the system being smart enough to know if you are close to home and the battery not needing to recharge.

Given the battery has 16kWh, but only accesses 8kWh during the normal cycle, if it dipped down below 35% to say 32.5%, for the 'dynamic responce' the engine can't provide after charge sustain mode is reached, then this amounts to an equivalent energy consumption to a range of 2 miles of driving.

If 8kWh gives 40 miles then 0.4kWh, which is the differential between 32.5% and 35% SOC, gives 2 miles. To recharge up to the sustain level from there would take far more than 2 miles even if the engine is running constantly at it's 50kW maximum. Given that after providing driving power it has a average surplus of 20% then it would take 10 miles driving to get back to the 35% sustain level. But if the computer knows you are not that far from home then it can leave the battery at the sub 35% sustain level and let it be recharged on plug-in.



Oh BTW, as to the Volt having sub-par performance after the electric only, I think the difference will be less than I thought because I now believe that the electric only performance will be a lot less than we hoped. Lutz was quoted as saying, “Our performance targets for the Volt are 0 to 60 in around five or six seconds. Top speed of 120 miles an hour for a limited time. A hundred miles an hour is sustainable.” Also, given the performance of the Tesla everyone expected good electric only performance. But as recently as his appearance on the Colbert Report it was down to I believe 9 seconds.

Now as to your dispute with me about it's post electric only performance. If you remember correctly I said that it's performance would be equivalent to small Euro economy cars. Even with the battery providing power for 'dynamic responce', to get 50 mpg, it will have to perform like a Euro economy car. It's not like they are snails, just not what Americans are used to.

But now I don't believe that there will be as noticeable a performance loss after electric only simply because now I believe that the Volt won't ever produce the higher level of performance from which to drop much from.

At 9 seconds 0-60 it will not be fast, and I'll bet that they tweaked that off the line benchmark so it doesn't sound as slow as it's normal driving performance will be. And by slow I mean normal economy car slow.

[goblue]

Originally Posted by Hybridized

Heh, now that I have read this thread and thought about it a bit, I offer up yet another opinion
I think of three battery phases, as a function of SOC:

1 35 - 85: EV mode, or with ICE for high power demands
2. 35 - 30: CS mode with ICE on powering car and sending juice to battery. Battery assist available. Unclear to me what happens in low power demand here.
3. =< 30: ICE only, battery recharging when car power demands allow it.

Phase 3, just like in a Prius, is unusual but certainly happens. The more aggressive the driver and more hilly the terrain, the more likely it is to come into effect.

That is all completely wrong. Why would the ICE come on for high power demands? The battery is perfectly capable of supplying everything the car needs at any moment. That would imply it has more capability when the battery is above 30%. Nope. When it gets low, the motor comes on and runs as necessary to keep it around the low set point.

Monaro, didn't really have any issue with you - my statement wasn't actually directed at you. But lets get real. 30%, 35%, whatever. By the time its launched it could be 28.6%

However, I want to make one thing patently clear. The VOLT will drive exactly the same regardless of the charge state of the battery. Anything else would be unacceptable to the public and complicated. Thats why it has a 0-60 of 8.5 sec and a top end of 100mph. And thats about what the Cobalt gets - most people consider that fine.

When it hits the lower limit, the generator comes on. It shuts off when the battery goes up a certain percentage. They picked the size of the generator such that it can meet the average power required under a worse case scenario, and then the locked out the scenarios which would require too much power. If you have a 200hp car, your average usage is much, much lower. Ever floor a car with an instant fuel econ meter - whats it read, 4, or even as low as 2. But you still get at least 15 (in a ordinary car, not SUV) even if you drive it very aggressively. How's that? Because you can only keep it floored for long periods of time in 2 circumstances. Driving up an extremely steep hill that happens to go forever (doesn't exist) or driving at the wind resistance top speed, which GM locked out. In normal, even aggressive driving you use the brakes, you coast, you have to slow down. This is not a race car. It won't work. GM has artificially limited its performance.

They've had mules of the system running around test tracks for months. Having it turn from a Cobalt into a Pinto when the battery hits 30% just doesn't make sense. Let that thought go. Its not real. This isn't a Prius or a 2 mode with all sorts of different modes. Its much simpler. Its an electric car with a generator and a sensor hooked to the batteries. This thing is 2 years away from release. Things will change.

Know how close to home you are? Why would it care? If the battery needs charge, it will run the motor till it hits a certain point. If you get home and the battery has 36% charge instead of 34% - who cares! Proximity to destination would be too complicated. This is designed for the average idiot - not the average engineer. It's designed for people who can't program their VCR. For people who need commercials every 5 minutes about the transition to digital broadcasting and will still be surprised when they can't use an antennae.

GM is simplifying all this stuff for the public.

Lutz's prior comments make perfect sense. 120 mph for short periods, 100mph sustained. Well, guess what - they decided that having different performance available at different times is too confusing. 0-60 of 6 seconds. Sure, then they decided it would take too much juice and aggressive drivers wouldn't get 40 miles - so they limited it. Thats what mule testing is for.

Debating details now is absolutely silly. Monaro is wrong. They don't matter. They will change. The base goals will be achieved. 40 miles of range, seamless, transparent operation for farther than 40 miles using gas at around 50 mpg.

[AMERICA 123]

Originally Posted by PhishPhood

OTOH.. in the response from Lutz several pages back he apparently said that all the power from the ICE went through the battery. Either the ICE output always does go through the battery ( series hybrid ) or it sometimes takes the path of least resistance around the battery ( parallel hybrid). Therein lies the conundrum.

He did not. He said all the current.

Yes, I know, but still......

[AMERICA 123]

Originally Posted by CaptainDan

Yes we do. GM has always said, 40 gas-free miles, then 50mpg.

Actually..... yes did not the 50 come much later ?

[MonaroSS]

Of course it may all be a matter of semantics.

I know that Bob is always very brief and to the point in his emails to me, a sign of a busy man. So when he says it goes through the battery we must remember that, unlike the simplicity that goblue seems to be envisioning, the Volt's power control systems are likely high complex physically and digitally.

So when Bob says it goes through the battery he may be meaning that it goes through the battery system.

That could make all the difference in understanding this......

[Hybridized]

Originally Posted by goblue

That is all completely wrong.

I think I have to amend my phase I after reading your post, and agree that ICE will always be off. Phase II and III as I wrote them still strike me correct.

[Hybridized]

What are the latest specs for range on one tank of fuel, and how large is the tank ?

[big swede]

Originally Posted by MonaroSS

Oh BTW, as to the Volt having sub-par performance after the electric only, I think the difference will be less than I thought because I now believe that the electric only performance will be a lot less than we hoped. Lutz was quoted as saying, “Our performance targets for the Volt are 0 to 60 in around five or six seconds. Top speed of 120 miles an hour for a limited time. A hundred miles an hour is sustainable.” Also, given the performance of the Tesla everyone expected good electric only performance. But as recently as his appearance on the Colbert Report it was down to I believe 9 seconds.

Now as to your dispute with me about it's post electric only performance. If you remember correctly I said that it's performance would be equivalent to small Euro economy cars. Even with the battery providing power for 'dynamic responce', to get 50 mpg, it will have to perform like a Euro economy car. It's not like they are snails, just not what Americans are used to.

But now I don't believe that there will be as noticeable a performance loss after electric only simply because now I believe that the Volt won't ever produce the higher level of performance from which to drop much from.

At 9 seconds 0-60 it will not be fast, and I'll bet that they tweaked that off the line benchmark so it doesn't sound as slow as it's normal driving performance will be. And by slow I mean normal economy car slow.

No this is actually what you said:

Originally Posted by MonaroSS

Is there a more politically correct word there in the US for mentally retarded because whatever it is those people, suffering from it like you two, seem unable to learn or understand basic information?

You cannot get more power out of something than goes into it, end of story.

Once the Volt hit's 30% charge then it's electric motor performance is limited by the power management computer in order to maintain that 30% charge. You two seem to think that the ICE is not finite in how much it can simply add in terms of power to the battery. The ICE has a MAXIMUM power output of 53kW, while the Volt's drive engine has a MAXIMUM output of 120kW. Up until the 30% charge limit is reached you can drive the Volt like a mad man and draw a constant 120kW doing constant doughnuts if you want, but after the 30% limit the computer will only let you draw out an average maximum of the 53kW going into the battery assuming 100% efficiency of the ICE. THIS IS A REDUCED PERFORMANCE.

The power available after the 30% limit is reached is LESS because the power management must make it less as the average power from the ICE is LESS than the drive motor could previously use - it has nothing to do with whether the batteries could provide more power if they were to go under 30%.

Morons......Is that the politically correct term?

The only part I even cared to disagree with you was that you said the power level would drop off from stock. I could care less at what level the engineers have the ICE begin to maintain battery level or what level it ranges between or when it should come on and for how long. Who really cares at this point because it will change before production starts and will continue to change as more vehicles get into public hands and more is learned about the driving habits of the owners. I could very well see GM send out a very detailed questionnaire to Volt owners after a year or so that will help them refine the settings even more.

It sounds like you are back pedaling now by saying it won't fall off as much as you thought because the performance is less than you anticipated and then trying to fill the thread with useless fact/opinions about charge levels.

GM just wouldn’t engineer a car that drops off so much when the battery power is gone for obvious liability reasons. If a more powerful electric engine was chosen then they would also need a more powerful ICE or have the ICE come on sooner and run at a higher rpm to maintain that battery level.

[MonaroSS]

Originally Posted by big swede

No this is actually what you said:



The only part I even cared to disagree with you was that you said the power level would drop off from stock. I could care less at what level the engineers have the ICE begin to maintain battery level or what level it ranges between or when it should come on and for how long. Who really cares at this point because it will change before production starts and will continue to change as more vehicles get into public hands and more is learned about the driving habits of the owners. I could very well see GM send out a very detailed questionnaire to Volt owners after a year or so that will help them refine the settings even more.

It sounds like you are back pedaling now by saying it won't fall off as much as you thought because the performance is less than you anticipated and then trying to fill the thread with useless fact/opinions about charge levels.

GM just wouldn’t engineer a car that drops off so much when the battery power is gone for obvious liability reasons. If a more powerful electric engine was chosen then they would also need a more powerful ICE or have the ICE come on sooner and run at a higher rpm to maintain that battery level.

No, that is not my quote about the power drop-off being down to Euro economy car levels. That’s a quote of where I inferred you guys were Morons.

And BTW I said that it would not fall off a cliff but the algorithms would ensure it transitioned down so as to not be dangerous.

And I'm not backpedalling on anything. My stance on the after electric performance is exactly the same; but with new information I am now downgrading my view of the electric only performance too.

Take or leave the additional facts I presented, you obviously like leaving facts out.

Just as people thought the Volt was not going to have ordinary proportions and styling compared to the Volt Concept, so too you people should downgrade your expectations for the performance or you will be disappointed like so many are with the Production Volt styling.

[goblue]

Originally Posted by MONARO

Once the Volt hit's 30% charge then it's electric motor performance is limited by the power management computer in order to maintain that 30% charge. You two seem to think that the ICE is not finite in how much it can simply add in terms of power to the battery. The ICE has a MAXIMUM power output of 53kW, while the Volt's drive engine has a MAXIMUM output of 120kW. Up until the 30% charge limit is reached you can drive the Volt like a mad man and draw a constant 120kW doing constant doughnuts if you want, but after the 30% limit the computer will only let you draw out an average maximum of the 53kW going into the battery assuming 100% efficiency of the ICE. THIS IS A REDUCED PERFORMANCE.

Wow. Monaro do you still believe all that you wrote above? I haven't been following this thread since the beginning for all the moron comments, but its looking like you've got some apologizing to do.

[MonaroSS]

Some more useless facts……………

The Volt has 8kWh of energy to use between 85% and 35% State of Charge to get it 40 miles distance. 8kWh of electric energy = the energy in 0.25 gallons of gasoline.

That’s 160 mpg.

But we have to translate this into electric motor v gasoline engine efficiencies.

The Tesla’s electric motor to wheel efficiency is 90%. If Volt’s electric motor is 90% efficient then only 0.225 gallons of gasoline equivalent energy gets to the ground.

Now lets look at a normal car using that same NET amount of energy to go 40 miles.

Modern gasoline/manual gearbox engines have an average efficiency 30% or less when used to power an automobile. So if a conventional engine/gearbox car used 0.75 gallons to go 40 miles then 30% of that would be 0.225 gallons of energy getting to the ground, the same NET energy as the electric Volt.

So, 0.75 gallons of gasoline to travel 40 miles equates to 53.mpg.

Given that the Volt is heavy for it’s size, what kind of performance do you guys think a conventional gasoline/gearbox engined Volt, or similar sized and weighted car, would give in order to get 53 mpg?

I’m thinking it would be somewhat under-whelming. So if the electric Volt has the same NET energy to travel the same 40 miles distance then it’s performance will be the same. In other words; under-whelming.

Knock yourselves out trying to disprove the facts……….

[MonaroSS]

Originally Posted by goblue

Wow. Monaro do you still believe all that you wrote above? I haven't been following this thread since the beginning for all the moron comments, but its looking like you've got some apologizing to do.

That quote big swede used is from a long drawn out argument in another thread months ago. He should have made that fact more clear for other readers.

As to the technical claims I made; I not only believe them 100 percent, but they are fact.

As to whether the guys I was arguing with were implicitly or explicitly Morons; I have to wait and see if any evidence emerges to contradict that notion.

I'm still hopeful it may happen one day.....