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

[MonaroSS]

Originally Posted by big swede

MonaroSS is conspicuous by his absence. Either he is tired of calling us a bunch of idiots because he still thinks it works completely different or he finally grasps that it might work much differently than he thought.

You must have missed my post No36 below:

Originally Posted by MonaroSS

WishIhadatruck, thanks mate for remembering that.

I explained how it all worked in detail and nobody in that thread believed a word I said......

This thread confirms one thing I claimed.

tamatt27's email from Lutz confirms another thing I and only a few others claimed.

What's the use of arguing with you guys when the truth with come out bit by bit supporting all I said.......

In the mean time I'm happy just chopping and having fun.

A little something for all those celebrity limo fleets..

[PhishPhood]

Originally Posted by goblue

Its automatically does what you suggest. the generator is hooked directly to the battery. The e-motor (via a variable control) is hooked to the battery. Electricity follows the path of least resistance. Here's a few scenarios.

So, lets say the generator (ICE) was running...

and you were accelerating hard. 100% of the power would be flowing from the generator to the e-motor AND more power would be coming from the battery. Again, it follows the path of least resistance.

Now, lets say you were accelerating at exactly the power put out by the generator. Zero power would go into the battery.

Finally, lets say you were accelerating mildly. Some of the generator's power would go to the battery and the rest to the e-motor.

Its all simple physics. Ever use your cellphone while its charging? Works just fine, and the phone has no crazy controller. Power is flowing to the battery and away from it simultaneously, with only the net difference going into or coming from the battery depending on what you're doing.

If true then in the three scenarios that you laid out above it seems to confirm my initial thought that in certain conditions the ICE+generator does power the e-motor directly, bypassing the battery. The path of least resistance as you note.

At this time during very strong accelerations or needs... hold your hats... the Volt would be a parallel hybrid being run at the same time by the ...
ICE ==> generator ==>
............................... both power sources feeding the e-motor by separate routes
PLUS: battery pack==>

Most of the other times the Volt is a series hybrid...
ICE ==> generator ==> battery ==> e-motor

Now the question is when the battery reaches it's lowest available level, say 30%, but the driver suddenly wants maximum output with the battery prohibited by software from contributing ( can't go lower than 30% ) is then the vehicle being driven ONLY by the..

ICE ==> generator ==> e-motor

with maybe a 'trickle charge' to the battery?

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.

[goblue]

Originally Posted by PhishPhood

If true then in the three scenarios that you laid out above it seems to confirm my initial thought that in certain conditions the ICE+generator does power the e-motor directly, bypassing the battery. The path of least resistance as you note.

At this time during very strong accelerations or needs... hold your hats... the Volt would be a parallel hybrid being run at the same time by the ...
ICE ==> generator ==>
............................... both power sources feeding the e-motor by separate routes
PLUS: battery pack==>

Most of the other times the Volt is a series hybrid...
ICE ==> generator ==> battery ==> e-motor

Now the question is when the battery reaches it's lowest available level, say 30%, but the driver suddenly wants maximum output with the battery prohibited by software from contributing ( can't go lower than 30% ) is then the vehicle being driven ONLY by the..

ICE ==> generator ==> e-motor

with maybe a 'trickle charge' to the battery?

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.

Phish, its the same thing. Through, around, whatever. If there is a net energy difference while the generator is running it will go into or come from the battery. No fancy controllers required, and nowhere is it a parallel hybrid. The Prius is antiquated technology next to this. Its a VCR vs DVD sort of thing. Toyota will copy it in short order. It's just better. Accept that. Had Toyota had access to great batteries when they built the first Prius it would have been designed like the VOLT. The concept of a series hybrid with a range extending motor is nothing new.

They set it at 30%, but GM will let it go down to 29 if necessary. It's near impossible to setup a scenario where you could use more than 70hp on average over any reasonable length of time. They locked out towing, locked out high speed operation, and sized the other components appropriately.

How do we know this? That's how GM sized the generator. They used powerful computers and real world data to analyze extreme scenarios, then added a percentage. Then, they built mules of the system, drove those all over to validate their analysis. It's just not that hard. I'm still trying to understand how some on this site think GM just messed up the calculations or just guessed at the generator size and now all the Monday morning QBs on a GM fansite are right and GM messed up. When it reaches 30% its done. Turns into a 1987 Ford Escort. Guess they should have asked us first, right? Because this site is just filled with electrical and automotive engineers with prior EV experience.

Also, a parallel hybrid implies an electrical and mechanical connection to the wheels. A series hybrid means the mechanical force is converted to electricity before reaching the wheels. The VOLT is a series hybrid with a battery. A modern diesel locomotive is a series hybrid without a battery.

GM approached it from the other end of the spectrum to make it appear as a completely different class. An electric vehicle with a range extending motor. Means the same thing.

There's a key point that needs to be made. GM is dumbing everything down for mass consumption. Reading into Lutz's statements too closely, pouring over every detail released will not give one a 100% understanding of this. What Lutz was trying to convey is all the power goes to or from the battery. Not necessarily into it or from it. Many of us on this site understand this because we're the type of people who just understand things like this. It's intuitive. Everyone is good at different things, but some people need to approach this with a leap of faith.

There are plenty of people on this site who are willing to patiently explain all this, but keep this in mind - if you think GM messed up, or just don't understand - just recognize that you probably just don't understand it. Telling others they are wrong is not appropriate unless you really understand it - and what you'll notice is those of us that really do get it just know enough to know what we don't know. We freely admit we don't have all the settings, calibrations, and exact details. However, many just don't even know enough to know what they don't know - and that's where mistakes like the one that started this thread come from.

[AMERICA 123]

Originally Posted by CaptainDan

A very good (and often asked) question.

Yes. And if we're going to say things with so much certainty, - well, just gotta' tighten it up a bit. None of this is anti Volt - its meant to tighten up the pro argument

This drivetrain configuration is indeed more <gasoline fuel> efficient than a <current > comparable <automatic transmission equipped > gas-engine driven one would be . Even with the same engine. < - except in at least certain relatively steady state highway conditions > Odd, you say?

There are many, many measures of powertrain efficiency.

As a rule that has yet to be broken and will likely hold for some time, all measures of efficiency involving considerations of things like mass, volume, and cost go to the gasser - or diesel - and that's hands down - no comparison.

However, as we all know, there are other measures of efficiency - and other capabilities worth having and therein lies the appeal of the Volt.

Further more , if we are at all realistic about it, it doesn't matter in the least for the overall argument in favor of the Volt that yep, the exact same 1.4L gasser with some sort of sensible manual transmission choice would in fact out mpg the Volt on the highway - nobody would be willing to buy such a car - or drive it.

You literally wouldn't be able to give it away. Its a useless 'disadvantage' - but we don't need to duck it or misstate it.

All powertrain systems involve all sorts of trade offs and choices - both within and without.

All make optimization trade offs.

There ain't a one thats perfect - including the ones I tend to favor.

The Volt's basket of optimization choices combined with that ridiculously strong PHEV capability are going to be very compelling for more than a few.

*********************
OFFTOPIC:

Another thing - also not intended as criticism - but as a suggestion :

The gas engine is there as a backup

GM refers to it as a "range extender" - which sounds better and is more accurate.

[AMERICA 123]

Originally Posted by CaptainDan

You compare the cheapest possible Prius to the highest estimated Volt price? Sounds fair

Particularly when compounded by a very generous 5% over 10 years.

There is also the battery replacement cost. The Volt's battery is a newer, better (but more expensive) design - the main reason the Volt is more costly. But it is MUCH longer lasting than the Prius type battery, which would never last 10 years. Even if the Volt's battery didn't last ten years, a new one would be free (warranty) - Prius does not offer that after 5 years. So, factor in at least one new battery.

In addition, it erroneously assumes 50mpg for the Prius.

Should've used a range of values between 38 - 45 mpg - with proper notation on the limitations of the values chosen. Can hypermiling get it higher - yea. Can other considerations drive it lower - yea - you bet.

Its biased every way possible for the Prius against the Volt.

Here is yet another nonsensical, misleading 'Pri' sound bit

Originally Posted by Hybridized

EdSuski,

Unless further EPA testing has been done I am unaware of, the quoted 50 mpg in charge depletion mode is from the easy 06 city cycle. This is the one Prius received a 60 mpg rating on. It was also this cycle I believe that EV comsumption was measured. I expect the median real-world to be quite a bit less EV range, and a lower ICE mpg in depleted mode.

[MonaroSS]

People should try to remember that Larry Nitz has already gone on record that the Volt battery will cycle between 35-85% SOC and can dip down below 35 into the old 30+ range of SOC....

[big swede]

Originally Posted by MonaroSS

People should try to remember that Larry Nitz has already gone on record that the Volt battery will cycle between 35-85% SOC and can dip down below 35 into the old 30+ range of SOC....

No one is doubting that so I'm not sure what that has to do with anything. I'm actually surprised the ICE would charge it as high as 85%.

The main disagreement is that you are the one saying there is no way the car will have very similar power once the battery has been diminished and the ICE is on. You have been saying it will then go into a reduced performance mode.

[AMERICA 123]

Originally Posted by goblue

It works like the thermostat in your house. When the temp drops to 68, the furnace comes on and pushes it to +1-2 degrees, depending on the thermostat. Then the furnace shuts off. If you ran your furnace constantly at a low rate it would be horribly inefficient, so it cycles. Same thing.

This furnace analogy is not what you what to use - you've got it flipped around. It is the lack of variable rate burner systems that results in the less efficient on off mode. A furnace or boiler - that can operate continuously is the most efficient possible. The common oversimplification into 1'speed' ( on/off) or the much rarer 2 or 3 'speed' furnaces is done in the name of complexity and initial cost reduction - not operating efficiency - which is traded off.

[fan]

I don't believe the engine or the generator are limited to that optimum rpm.
If the battery is discharged and the driver keeps flooring it, the gas engine could be revved up(maximum power) so that the generator produces enough electricity to keep up with driver's will. So, it shouldn't happen for one to not be able to get through hills if the battery is depleted.
But this would be a highly undesired case. Stress the battery and increase fuel consumption.
If a diesel engine-generator setup works for a locomotive it would work for a Volt too. The engine of a diesel locomotive is surely not limited.
However, I still don't get it why some power cannot be sent directly to the wheels from the generator when ICE is running. Charging-descharging decreases life of the battery.
This could be a good PR thing too. Volt works both as a paralel hybrid(without mechanical transmission (gas engine-generator-emotors)) and mostly as a series hybrid.
So, it does what Prius does and even more than that!

Edit: And having a direct path from generator to e-motors, would allow sending as much power is needed to the wheels when battery would be discharged. This would allow designing a battery that doesn't have to cope with extreme conditions.

[roteague]

Originally Posted by Hybridized

I have a Prius that cost about $25k without tax credits.

I'm sorry ... then again, I'm sorry that anyone would willingly own a Toyota.

[jry]

Originally Posted by drew630

So basically the gas motor is like one big alternator that provides power to the electric motors but doesn't charge the batteries? Sorry, I am really confused on how this system is suppose to work.

Its a very efficient 4 cylinder generator (will be built in Flint). It will power the electric drive and all of the accessories. The mileage, with the engine running, should be extremely good. More cars should use the generator idea.
I believe the onboard batteries never get below 50%, depletion. This extends their life. I'll bet you can tap that extra energy in an emergency.

[MonaroSS]

Originally Posted by big swede

No one is doubting that so I'm not sure what that has to do with anything. I'm actually surprised the ICE would charge it as high as 85%.

The main disagreement is that you are the one saying there is no way the car will have very similar power once the battery has been diminished and the ICE is on. You have been saying it will then go into a reduced performance mode.

No you are not correct. Look up the page to see goblue's post which I quote below with the red highlight how he's working with the old 30% SOC and talking a bout dipping below that, when it's now 35% SOC and dipping from that new higher level. Just wanting to clear that up as goblue in his last paragraph seems to be having a dig at me for not patiently explaining things, and that in bold at the bottom I don't know what I'm talking about.

So I am here now patiently explaining to goblue and the rest of you who don't know that it's 35% not 30% SOC that is what the Volt system is set to charge sustain above. And that goblue doesn't "just know enough to know what [he doesn't] know".

Originally Posted by goblue

Phish, its the same thing. Through, around, whatever. If there is a net energy difference while the generator is running it will go into or come from the battery. No fancy controllers required, and nowhere is it a parallel hybrid. The Prius is antiquated technology next to this. Its a VCR vs DVD sort of thing. Toyota will copy it in short order. It's just better. Accept that. Had Toyota had access to great batteries when they built the first Prius it would have been designed like the VOLT. The concept of a series hybrid with a range extending motor is nothing new.

They set it at 30%, but GM will let it go down to 29 if necessary. It's near impossible to setup a scenario where you could use more than 70hp on average over any reasonable length of time. They locked out towing, locked out high speed operation, and sized the other components appropriately.

How do we know this? That's how GM sized the generator. They used powerful computers and real world data to analyze extreme scenarios, then added a percentage. Then, they built mules of the system, drove those all over to validate their analysis. It's just not that hard. I'm still trying to understand how some on this site think GM just messed up the calculations or just guessed at the generator size and now all the Monday morning QBs on a GM fansite are right and GM messed up. When it reaches 30% its done. Turns into a 1987 Ford Escort. Guess they should have asked us first, right? Because this site is just filled with electrical and automotive engineers with prior EV experience.

Also, a parallel hybrid implies an electrical and mechanical connection to the wheels. A series hybrid means the mechanical force is converted to electricity before reaching the wheels. The VOLT is a series hybrid with a battery. A modern diesel locomotive is a series hybrid without a battery.

GM approached it from the other end of the spectrum to make it appear as a completely different class. An electric vehicle with a range extending motor. Means the same thing.

There's a key point that needs to be made. GM is dumbing everything down for mass consumption. Reading into Lutz's statements too closely, pouring over every detail released will not give one a 100% understanding of this. What Lutz was trying to convey is all the power goes to or from the battery. Not necessarily into it or from it. Many of us on this site understand this because we're the type of people who just understand things like this. It's intuitive. Everyone is good at different things, but some people need to approach this with a leap of faith.

There are plenty of people on this site who are willing to patiently explain all this, but keep this in mind - if you think GM messed up, or just don't understand - just recognize that you probably just don't understand it. Telling others they are wrong is not appropriate unless you really understand it - and what you'll notice is those of us that really do get it just know enough to know what we don't know. We freely admit we don't have all the settings, calibrations, and exact details. However, many just don't even know enough to know what they don't know - and that's where mistakes like the one that started this thread come from.

[AMERICA 123]

Originally Posted by PhishPhood

Now THAT is interesting. Everything DOES go through the battery.

Mind boggling on the first pass.......

Later...... even more mind boggling on the second.......

Third pass...... well.....

One thing for sure, the Volt is going to be a game changer, - more ways than one.

Something is more advanced somewhere.

There has to be a missing piece to this puzzle -.................

Ok, just for discussion I'll throw the most unlikely one out - that actually would fit the numbers - but definitely not the verbiage.

There is a direct mechanical IC pathway. (50mpg - combined ??)

Still no need for a tranny - use the electric portion of the drivetrain as a different kind of load leveler.

[pinyon]

Saw this on another thread with some conflicting info from Rob Peterson at GM.

http://biz.yahoo.com/ap/080925/gm_en...lant.html?.v=4

GM initially said the Volt would be able to run 40 miles on its lithium-ion batteries, with a small internal combustion engine recharging the batteries to extend the range hundreds of miles. A top executive said the same thing as recently as last week.

But company spokesman Rob Peterson said Wednesday that engineers changed the design so the Volt engine will power a generator that would run the electric motor after the batteries are depleted. A small amount of power from the generator will recharge the batteries, but most will be used to directly run the car, he said.

He said bypassing the batteries is more efficient, and GM did not intend to deceive people by maintaining that he motor would only be used to recharge the batteries.

"At the end of the day, to the consumer, the vehicle will operate much the same way," he said.

[big swede]

Originally Posted by MonaroSS

No you are not correct. Look up the page to see goblue's post which I quote below with the red highlight how he's working with the old 30% SOC and talking a bout dipping below that, when it's now 35% SOC and dipping from that new higher level. Just wanting to clear that up as goblue in his last paragraph seems to be having a dig at me for not patiently explaining things, and that in bold at the bottom I don't know what I'm talking about.

So I am here now patiently explaining to goblue and the rest of you who don't know that it's 35% not 30% SOC that is what the Volt system is set to charge sustain above. And that goblue doesn't "just know enough to know what [he doesn't] know".

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.