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The Chevy Volt Generator Will Run at One of Several Fixed RPMs
August 26th, 2008 | Posted in: Engineering, Generator
People often ask how the Volt’s combustion engine will run after the first 40 EV miles have been driven. It seems that if the generator runs at a fixed RPM, the efficiency of the system will be greater than if it is allowed to vary. Since to this point GM has never publicly told us whether it will be fixed or varied, having had the chance, I asked Volt chief engineer Andrew Farah.
Will the engine run at a fixed or variable RPM depending on the amount of power you need at any given time?
We’re going to tune the system to operate efficiently at a few points. The RPMs of the engine aren’t going to follow your throttle pedal as they do in a typical car. It will run at some various RPM speeds.
So these various possible levels the engine will run at wont be determined by the pedal, but by the needs of the car as a computer calculates?
Yes.
So the answer sort of is, both.
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Posted by: Lyle
August 26th, 2008 at 8:35 pm
Lyle,
Thanks for the update. This answers one more question I had about the Volt. Much appreciated. We should have a pop quiz about Volt facts to see who is up to speed.
August 26th, 2008 at 8:36 pm
sweet
now we know. I had been wondering about this for a while just like I’m sure lots of others had. Thanks again Lyle
August 26th, 2008 at 8:37 pm
This operating stategy seems like the most logical way to get the most efficiency from the ICE unit, as well as the best way for the engine to be constantly ready for power requirement changes. Sort of like my Honda inverter generator — Let the computer figure out the engine speed requirements.
August 26th, 2008 at 8:42 pm
Lyle — very informative. Thanks to you and Mr Farah for this information.
August 26th, 2008 at 8:44 pm
Lyle,
I saw in a website that Flint has agreed for the Tax Breaks. Will it be possible to obtain some more information on the time-lines for the engine Plan construction.
August 26th, 2008 at 8:48 pm
They may not have publically stated that but I think it was pretty much understood that this was the going to be the case. The new information is that it will be at a number of fixed options instead of continuously over a limited range.
IE instead of 1200 up to 2500 rpm’s - 1200, 2000, 2500 or 3000 rpms
Probably some other measure other than rpms but theory remains the same.
August 26th, 2008 at 9:05 pm
Makes sense.
It beats user controlled input as most users wouldn’t judge their needs too well and burn too much gas. The computer should easily be able to track voltage draw and voltage demand over time better than any meatsicle.
August 26th, 2008 at 9:06 pm
Sure hope it doesn’t turn on while parked in some public garage. I’ll bet they figured that out.
August 26th, 2008 at 9:10 pm
I wonder if the computer will take into account how cold the outside temperature is. Will it start up a few minutes before it is needed to warm up the coolant before being subjected to the generator load?
After 100 years of controlling a motor with a throttle attached to the carburator (or FI), its gonna be weird for many pulling up to a stoplight with the engine still running hard.
August 26th, 2008 at 9:15 pm
Why stepped rpm’s vs continously variable? Is the ICE or the generator efficiency driving this. I thought piston contours can be optimized for certain speeds while generators can operate at various rpm’s easily. Does anyone know?
It’s always great to hear solid news like this. The devil is always in the details right.
August 26th, 2008 at 9:15 pm
All the more reason this engine should be a diesel.
August 26th, 2008 at 9:19 pm
It seems that this blog is giving away a lot of secrets to the competition. Battery specs, charging strategies, iPod connectivity, etc. I’m sure there are a lot more juicy details that GM isn’t revealing, but there is a fine line between revealing secrets to the competition and keeping up public interest in the vehicle, which this web site seems to be doing a good job of.
I think I’m addicted.
August 26th, 2008 at 9:23 pm
Then I think engine will be off at certain times when SOC of the battery reaches some threshold, say from 30% to 35%.
Another question:
How will the battery cool itself when parked without plugged in for a long time, say for a month ? Will it use its own battery power to cool it ? or will it use ICE to cool and shallow recharge ? what if there is no gas in the tank ? will the battery continue to drain to cool itself till it reaches certain SOC ? say 40% and leave it there till driver starts the car ? the remaining 10% will allow him to go to a near by gas station when he comes back. Of course it will be indicated by some SOC and fuel guage. Any idea guys ?
I think there is no need to worry about parking the car in extreme cold(-40c) as the Li ion batteries will be happy to stay there for a long time if we don’t extract any charge from it. As soon as the driver starts the car, the battery can be heated to deliver the optimum performance.
August 26th, 2008 at 9:32 pm
This is interesting.
If you look at AC Propulsions white papers on there range extender,
they actually run a “cycle” where they minimize polution, and max effeciency. The end result is once its “up” and “running” its a fixed rpm.
Really dont see the need to “vary” it other then for polution control at startup time. Really feel that you run the beast at Best Possible RPM for the generator, let the battery absorb what it can. Once we get the battery topped up, we shutdown.
Unless you think you have a “charge” cycle limit on the battery, this is the best strategy, and the best fuel usage.
Go dig a bit on AC propulsion papers, these guys did it 10+ years ago, and pretty good. Yes today we would do things a bit more digital, but there white papers and understanding is really good.
August 26th, 2008 at 9:33 pm
Interesting. Thanks for the info.
August 26th, 2008 at 9:37 pm
I bet I have read hundreds of posts where everyone and their dog seemed to believe that the key to the Volt’s efficiency (while on the generator) was that the engine would run at a fixed, most-efficient RPM. Now having multiple RPMs is the cat’s meow?
If there is one RPM that produced the ultimate efficiency then this change means that the Volt has just become less efficient. If it turns out that any one specific RPM does not provide much of an efficiency increase then the Volt isn’t going to be near the 50MPG highway mark (as it will be lucky to be as efficient as the implementation in the Cruze which will most likely will do ~40MPG highway).
August 26th, 2008 at 9:39 pm
Sounds good…. when climbing steep hills it will be at the highest RPM and other times when it’s running somewhere in between.
The whole idea is to not have the generator produce too much excess electricity… don’t want to put too many needless charge/discharge cycles, even if it’s just 1-5% of the battery’s capacity, as it will add up, especially on long trips, to decrease the life of the battery pack.
Thumbs up GM
edit: I see a few more posts before mine got posted… yes, they are probably giving up a little efficiency by not running fixed RPM all the time when it’s on…. but given how expensive the battery packs are, making sure it lasts 10 years or 150,000 miles is more important
August 26th, 2008 at 9:51 pm
4 speeds. Makes sense. Variable valves are great for varying RPMs but fixed RPM is ideal. That was one of the main simplicity points in not copying Toyota’s series/parallel design.
Sometimes I wonder if Toyota’s tranny might assist with max efficiency while regenerating with ICE. That way you could have low RPM with the max gear ratio. The Volt won’t offer such a thing for simplicity’s sake. Maybe that’s a good thing for GM’s first PHEV, but maybe that will be Toyota’s extra trick.
I’d like diesel too, but I don’t think they can make it quiet enough - you’d really notice it going on and off - but a gas engine can be almost silent when it comes on and off like the Prius/Camry/RX400h.
What I’d like to know is: Will there be a way to pause ICE regeneration in special situations?
For example, GPS or a “almost home” or “regen hold” button when the car is near a free source of downhill kinetic energy or is near home but doesn’t know it?
I have had several opportunities in the Prius to take advantage of the free energy of a long downhill decent from a mountain. But I couldn’t tell the car not to keep charging to full capacity because we would be reaching the top of a mountain soon.
The same with being “almost home”. Currently there is no PHEV or hybrid that lets you tell it to wait just a little longer for food, like a hungry kid who want’s to stop at a carry out place on the way home and doesn’t want to wait for the better, cheaper dinner that’s there.
August 26th, 2008 at 9:54 pm
DIESEL … UUUGGGHHH!!!
I wouldn’t buy it, burning GAS in an ICE is bad enough. I’m still hoping for an SOFC fuel cell that converts any hydrocarbon directly to electricity, or a PEM fuel cell with a (hydrocarbon) REFORMER.
August 26th, 2008 at 10:00 pm
I am happy to hear this. Truly…this will be the drive train of the future.
I wonder if the range extender’s ICE will double the efficiency of it’s brother in the Cruze.?
August 26th, 2008 at 10:01 pm
Thanks Lyle, the last post on the subject left me with more questions than answers and I think this pretty much clears it up. As stated above, I think it’s much better having a computer control the motors as opposed to human intervention. We’ve got enough to think about just driving safely then to play a video game with our car (although I gotta admit it’s fun to play the mileage game in the wife’s prius).
August 26th, 2008 at 10:04 pm
The engine operating parameter is likely to have two criteria at least (that I can think of) One will be to maintain the SOC at max engine EFFICIENCY - likely to be one particular speed (given that the generator load will be constant (or will it) that speed is not going to be a range, it’s going to be specific. The other - generator demand load - may be one for performance requirement - this is could be a range of speeds dependant upon PERFORMANCE demand. All of this assumes coupling the battery output level with the engine/generator output level to augment performance. The one thing the software will not be able to work out - in most examples at least will be the driver profile with respect to journey versus charge time. So for instance you are cruising along at the bottom SOC level, the engine might decide to kick-in to top up the battery to a fuller SOC. However if you are only 2 miles from your re-charge station, this is a bit counter-productive: It’s going to be better to have the power come off the grid than from the engine and only the driver is going to be able to input that. Perhaps some driver input would be useful to enable the computer to make the appropriate selection. It would be nice to see the GM thinking on this but perhaps the it’s the Holy Grail of proprietary knowledge that can make or break the Volt.
August 26th, 2008 at 10:05 pm
Well, let me guess what a couple of these operating points will be:
first, there is a point about 2000 RPM and about 80% full throttle that represents maximum ICE efficiency. Then there is the mode most commonly know as “off”. Another mode is “full power” which one might need when going continuously up a mountain pass. I’m guess one might want at least one more step between 80% throttle and 100% full power. Don’t know about the sensibility of having any settings between 80% and “Off” — seems like the battery pack can handle the intermediates there?
August 26th, 2008 at 10:11 pm
Jimmy #1
“…who is up to speed.” Doesn’t this depend on my battery requirements ? arf, arf
August 26th, 2008 at 10:12 pm
My neighbor had a Ford Festiva for many years. His job required him to fly to Puerto Rico every two weeks, and this little car was perfect for going to the airport and leaving it parked there while in PR. He just retired and is moving away. He sold his little one-owner Festiva to someone for $200. It gets forty-some miles per gallon. I wonder if the Volt will be any greener than the Festiva. I know it will never be as economical, especially when one weighs in depreciation expense.
August 26th, 2008 at 10:23 pm
Jay@23
You can unsubscribe very easily. Personally, I welcome any info and certainly don’t consider the info “spam”.
Be well,
Tag
August 26th, 2008 at 10:26 pm
Another reason why this seems like a good idea is so you don’t have panicky drivers. It would be a little weird pulling up to a stop light and have the engine singing along at 3000 rpm, some peoples instinct might be to mash the brake pedal.
When the ICE is running the rpms will probably follow along the rpm points that would resemble a normal car. This would make sense power generation-wise also because power requirements increase with the cars speed.
August 26th, 2008 at 10:29 pm
Varying RPMs will also mean a longer life and even wear for the ICE. Very good.
August 26th, 2008 at 10:39 pm
—
10#
Cautious Fan Cautious Fan Says:
August 26th, 2008 at 9:15 pm
Why stepped rpm’s vs continously variable? Is the ICE or the generator efficiency driving this. I thought piston contours can be optimized for certain speeds while generators can operate at various rpm’s easily. Does anyone know?
—
I will venture a guess that is is because the timing is fixed. That is that the engine uses a camshaft that has particular rpms that give good efficiency vs good power. The step in engine rpm will no doubt follow the best points that are used in the specific camshaft that is being used.
August 26th, 2008 at 10:40 pm
Gary said…
“I think I’m addicted.”
Welcome to Voltaholics Anonymous. I’ve been addicted for over a year now and keep failing the 12 step program.
August 26th, 2008 at 10:41 pm
“my old Festiva got 45 mpg”
Prius drivers are sick of hearing that because Festivas were death traps. Most cars not built to new IIHS standards are death traps.
Here’s a lovely video of a big American 4×4 killing it’s driver….
http://www.youtube.com/watch?v=lB0araA0T_k
Here’s something like the Festiva mutilating it’s owner…
http://www.youtube.com/watch?v=mciUK50JPFk
A nice American minivan killing mommie…
http://www.youtube.com/watch?v=24SDvxQX-Yw
And here’s the Prius proving it’s safer than all of the above…
http://www.youtube.com/watch?v=7wg45haoZDg
Hmmmm…..still want a used Festiva or a used “big safe” car?
August 26th, 2008 at 10:42 pm
#26. I understand what you are saying. There were a number of cars from the late 70’s to the early 90’s that get 40 mpg. The problem now is weight. Your Festiva is a very light car, probably less that 2000 pounds. You can’t buy a car that light today. Cars today have anti lock brakes, 6 air bags, traction control, OBD-II (Extremely complex fuel systems that are self diagnosing), tire pressure monitoring, and must meet federal crash standards. Most of the weight gain is caused by more restrictive governmental standards. The good thing is cars are far safer, the trade off is you can’t chose to buy light (effecient) car anymore. A new chevy Impala weighs about 4000 pounds. A full size ‘57 chevy is a little larger but a lot lighter. You have to compare a car like the Volt, Cruze, etc with current designs from competitors. I would love to have a 0 mileage 1992 saturn SL with manual steering, manual brakes, 5 speed, no cruise control etc. They don’t make them anymore.
August 26th, 2008 at 10:45 pm
someone call the wahmbulance for jay please
August 26th, 2008 at 10:48 pm
Sounds like it will run like a normal generator (constant RPMs). That’ll be weird in a car though, especially when stopped. o.o
August 26th, 2008 at 10:52 pm
Talks asked many questions…
“How will the battery cool itself when parked without plugged in for a long time, say for a month ? Will it use its own battery power to cool it ? or will it use ICE to cool and shallow recharge ? what if there is no gas in the tank ? will the battery continue to drain to cool itself till it reaches certain SOC ? say 40% and leave it there till driver starts the car ? the remaining 10% will allow him to go to a near by gas station when he comes back. Of course it will be indicated by some SOC and fuel guage. Any idea guys ?”
Let me guess … you work for Toyota? Maybe Lyle could convince GM to post their engine and battery controller source code.
Seriously … I think such implementation details would benefit GM’s competitors more than us. I just want the Volt to go and stop when I tell it, and I want it to tell me when it will run out of juice/gas.
August 26th, 2008 at 10:58 pm
Thank you for the information. In my experience with CVTs in the late 1980s we discovered that the public expects certain sounds and jerkiness from their cars and if they are missing they ask for these imperfections. Our CVT incorporated steps in the shift computer to more closely simulate gear changes. When we ran the transmission in optimum mode for either max hp or max efficiency the perception was “it sounds funny”. At max hp it did not seem as fast but it was much faster without all the jerking. One solution is to provide a switch input to your computer that the driver can change to either run the best the car can do, or simulate the lunging that cars do now. During the test drive just flick the switch and watch the expression.
August 26th, 2008 at 10:59 pm
Thanks Lyle!!! This tells us a lot about how the gas engine will behave, and the driving experience of the Volt after 40 miles. This is really a great site…
August 26th, 2008 at 11:00 pm
I would like to thank Lyle for getting to the bottom of this. It was of obvious interest based on the last thread.
Lyle I have a request.. (I’m probably the only one that cares…)
Could you find out how the heat and a/c heat pump will work? If the engine is on will it bypass the heat pump and use engine coolant (will it have a heater core)?
August 26th, 2008 at 11:07 pm
My guess on the multiple rpm setup is that it is dependent upon generator load.
Operate at the lowest efficient rpm in driving mode only
Operate at next rpm level when the a/c and/or radio is turned on
Operate at next rpm level when you decide to turn on absolutely everything @ the same time
sounds about right…
August 26th, 2008 at 11:07 pm
#37 Paul-R:
No. I don’t work for Toyota, I am a software professional.
Suddenly I felt that I know everything about VOLT and how it should
work. I have started preparing Flow charts for ICE operation and
battery discharge while parked with plug on and off. I will post it as soon as it is done.
August 26th, 2008 at 11:23 pm
why would you cool the battery when it is parked?.. these batteries only heat up when used hard.. and not much at that!.. they run a lot cooler than the usual lithium cobalt batteries.
My guess the cooling option is only used in Death Valley, otherwise it will never come on, probably just a fan blowing air thru the battery. Now, in very cold conditions batteries just dont work, so something will have to be done about it.
August 26th, 2008 at 11:26 pm
Boy, I sure hope you won’t be able to hear that engine. It could be pretty annoying and/or disconcerting to hear it stepping between several discrete RPMs suddenly, without smooth transitions in between. Well, even WITH fairly smooth transitions, it might seem unusual or distracting. Guess I’ll have to wait to hear ‘the real deal’ and decide whether that’ll bother me or not.
August 26th, 2008 at 11:29 pm
#36 Mike
I’ve seen several comments about the ICE running when the wheels weren’t turning. I’m assuming the engine will stop when the wheels stop turning, which may in part be due to the comment that “The engine comes on to make enough electric energy to turn the wheels, because the wheels are always turning electrically.”
Stopping the engine when at a stop seems pretty basic at this point in time, no? Then again the famous graph didn’t really show this, though it seems to have been illustrative rather than definitive.
August 26th, 2008 at 11:30 pm
@40 Belloc:
>> Lyle I have a request.. (I’m probably the only one that cares…)
>> Could you find out how the heat and a/c heat pump will work?
No, you’re not the only one, that’s for sure! I live in Wisconsin and I often wonder how the HVAC will work, and its effects on AER and battery life. Consider the info request seconded!
August 26th, 2008 at 11:31 pm
Jay @31 - Besides the “unsubscribe” link on the email you just received, there is a check box on your page in the “Waitlist.” You pick the “Wait List” button, then enter your email, and click continue, then on your page there is a box to check which says, “I would not like to receive email containing news and important updates about the Chevy Volt.” Did you try that?
August 26th, 2008 at 11:38 pm
#43 Herm Perez
What I heard is Li ion batteries work at its best when temp is around 20c. Storing the battery at higher temperatures with high SOC will decrease its calender life. So its important that the battery be cooled
when parked without plugged in and when the outside temperature is high. However, by using good insulation for batteries (like vaccume), need for cooling the battery can be decreased though not completely eliminated.
Storing the Li ion at extreme low temps is not a problem but discharging the batteries at low temps will decrease its cycle life.
So as soon the driver starts the car, batteries can be heated to bring it to the optimum temperature.
August 26th, 2008 at 11:42 pm
As another point, it sure would be nice if the other 25516 people on the wait list would enter their location (state or country) and the other three items being tracked in the “wait list data.”
August 26th, 2008 at 11:44 pm
This is definitely not spam for me. Thanks for the update, Lyle!
You would use this, for example, if you are just a few miles from home and you know you will be able to plug it in, in a few minutes, or even if you were say 50 miles from your destination). You might have limited acceleration in this mode but this should be your choice if you are that kind of a driver… on the other hand, if you absolutely need more power temporarily, then give it more RPMs for a minute or so. Anyway, to make this concept work GM would need to estimate the battery power consumption rate of “average” driving conditions (which I am sure they have), they should then design/choose the engine based on this info, to provide exactly that amount of power while at its most efficient RPM. You can vary the RPM from there depending on need.
Back to the point. I want a car to be as ICE independent as possible, meaning I don’t want that ICE turned on at all if possible. I certainly don’t want it on for the sole purpose of recharging my battery. What I think would be best for me is to use the battery all the way down to say 10% reserve, and then have the ICE give me just enough to power the car to drive as long as I need but keeping the battery at about 10%, indefinitely, until that evening’s plugin charge. This could however be a manually set mode that you can select on the information display and could be called the “antiterrorist gas saver mode”
This seems obvious to me, why would anyone want to top of their battery with an ICE. That is exactly what the point of this car is not to do!
Love the car, can’t wait to see what it looks like. I really hope they keep the feeling of the concept car…beautiful. The new front is still great, but I am a little bit nervous about the rear looking like a 4 door sedan…keep it unique and smart and yes, aggressive looking.
August 26th, 2008 at 11:46 pm
I’m not sure this clarifies much of anything. All it means that the engine doesn’t run at a single fixed speed and the engine speed doesn’t vary directly with the throttle. Not really a surprise.
IMHO the engine won’t have a need to operate over as wide a speed range as a conventional car so it can be optimized somewhat for the operational range. I don’t really expect we’ll be informed of much more specific operation any time soon.
August 26th, 2008 at 11:58 pm
Thanks for the update,but the Chevy Volt faces far more pressing
problems than RPM speed issues.The biggest problem,GM has,is
making this vehicle affordable for the masses.If people can’t afford
to buy the Volt,GM will have to worry about cost issues first!If G.M.
plans to ask 40-45K for the Volt,it is going to fry a lot of wallets.Instead
of trying to make an electric “Caddy”,they need to come out with a
“Chevy” priced car,to market to the public.First things first G.M.
Thanks
August 26th, 2008 at 11:58 pm
40 Belloc:
>> Lyle I have a request.. (I’m probably the only one that cares…)
>> Could you find out how the heat and a/c heat pump will work?
<No, you’re not the only one, that’s for sure! I live in Wisconsin and I <often wonder how the HVAC will work, and its effects on AER and <battery life. Consider the info request seconded!
Living out here in Minnesota - consider it thirded.
August 27th, 2008 at 12:02 am
When can I get one without the “generator”? I am definately ready for the pure EV now.
August 27th, 2008 at 12:07 am
So, the ICE will be quantum mechanical?
August 27th, 2008 at 12:25 am
OK, now this goes against what was said yesterday - that there would be a direct connection from the generator to the motor but more in-line with what was said a few months ago - generator will run more like a furnace cycle.
There are a few points that need to be clarified.
1) The RPM of the generator does not necessarily determine the amount of power produced. That will depend on the magnetic field strength. Thus, the generator could be spinning at 2000 RPM and only producing a small amount of current and the ICE would be under very low load. The generator could also be spinning at 2000 RPM and pumping out a ton of power and the ICE would be under heavy load. Those two conditions will mean completely different things from the view of the ICE.
2) If this is the case will the magnetic field be varied to fulfill the demands of the motor? If so, the ICE will see varying load on its power shaft.
3) Thus, is the battery really always connected between the generator and the motor. This would allow the generator to run at constant speeds while the motor is going all over the place.
Well, GM. Which is it!?! You are giving out conflicting information and people are making all kinds of false conclusions. Perhaps this is your intentions. However, if that is the case please just say so. Say we are being vague for competitive reasons. Then we can all understand and go about our business. Thank you.
August 27th, 2008 at 12:32 am
I get the distinct message that WRT Gen 1 they’ll do what is necessary. No surprise here. I’ve said it before that one of the SIGNIFICANT refinements of Gen 2, 3 etc… will be the efficiency of the ICE. There is and will be much work to be done here. Hang in there!
August 27th, 2008 at 1:03 am
KISS! KISS! The only way we’ll be able to afford it!
Metros & VW Diesels get 40 to 50 mpg and are very simple machines.
August 27th, 2008 at 2:01 am
Hi from europe
a) I just unsubscribed for the third time but keep getting these mails. - So it is NOT that easy to unsubscribe.
b) I drive a current 2008 Ford Fiesta (Mk6 facelift) with 1.4l diesel engine getting easily 45 MPG (and it has a 4star rating at euroNCAP) - weight is around 2400lbs
c) Yes, weight is an important issue, and I basically the Volt´s advantage on predominantly short trajectories in the city, where the engine (in the Volt) is not subjected to continuous RPM-changes. I use the car basically for large highway travels (once a week 600miles+ in a day) and I need sth with low weight and low drag coefficient –> http://www.loremo.com - still 2 years away though
cheers
matt
August 27th, 2008 at 2:06 am
#22 Ian Porter Perth Australia probably has it about right.
One point for maximum efficiency, close to the typical running energy needs. One for maximum power for those quick jaunts up to 10 thousand feet.
Maybe a compromise point in between in case your mountain travel is not quite so extreme.
Initially, I was thinking maybe a “quiet” mode at low RPM but I suspect that won’t make sense to use anything lower power than the maximum efficiency point since the batteries will still provide a buffer and the engine could cycle a bit. I theorize it would be more efficient to charge/cycle than to run the engine at a less efficient point. Therefore, the only reason you would run the engine at a less efficient point is for higher power needs.
August 27th, 2008 at 2:24 am
If only they could do a little more work on the battery. If it was possible to get 100 miles out of it and then use the house or the product link below to top up. There would be no need for an engine at all.
http://www.parkandpower.co.uk
August 27th, 2008 at 3:03 am
this is sort of an obvious issue although of course they could do it down right wrong.
what is more interesting is why they don’t have a smaller engine in it since it only has to provide the average. weight is an enemy of efficiency
August 27th, 2008 at 4:15 am
Orentation of this power train …..
I wonder if the Diff housing will be facing the front ?
That would make the petrol engine on the right had side when viewed from the front.
OR
will it be the tradtional petrol engine on the left - viewed from front and the diff to wards to passenger cabin.
Can anyone shed some light on this?
Also the aluminium housing would need to contain besides the differential the electric motor and the seperate generator plus the the higher voltage drive electronics on top…….
interesting.
August 27th, 2008 at 4:20 am
i just saw a great piece on green cars on one of those “discovery channel types” of stations. really woke me up to the advantages of hydrogen, which i have always figured was too complicated.
it seems that i remember early talk of a volt with a generator that runs on hydrogen. the show i saw made it sound like this type of vehicle would be almost a “perpetual energy” machine. nice, if it works.
i too am off the emailing list for this site, it was just taking up too much time. but, i do appreciate it when lyle sends one of these out once or twice a month, just so i can catch up.
Grizz how you doin’ ole friend?
August 27th, 2008 at 4:48 am
Personally, I think 1800 rpm from the ICE should be adequate enogh rpm to charge any battery. Let us look at how efficient the A/C units operate today from the 1000 rpm to 2000 rpm. I would think this accessory has to be considered as a consumer to power up as well. I sure would not look for the Li-Ion battery to run your A/C.
August 27th, 2008 at 5:03 am
Thanks Lyle,
I just ordered my t-shirt for me, and my chevy salesman.
I was wondering if the inners of the volt would work on the malibu body?
Also, politicians are going to push this direction. Assistance to not only the consumer, but the auto makers themselves. I am sure glad chevy left the station, it looks like all are getting aboard.
thanks again, howard (#464)
August 27th, 2008 at 5:25 am
Ditto on the almost home button. Comming that last mile down Palm Beach Blvd while the gas generator fires up is just not efficient.
Take Care,
TED
August 27th, 2008 at 5:47 am
Glad to see this discussion is finally over, and that they made the right decision. Keep up the good work GM.
The Engineers have the sagacity
The batteries have the capacity
To end our useless toil for oil
Deliver the Volt
Don’t let the momentum spoil
August 27th, 2008 at 6:07 am
Lyle,
1.to extend the battery charge without using the ICE, could the kinetic energy be recaptured in the drive train or off rear wheels somehow by using generators to trickle charge to extend battery range? Still would be energy loss but could extend the battery mileage distance without ICE.
2. What about built in solar panel in roof to charge will on the move or while parked outside at work?
Just simple ideas but Im not an engineer so dont know the drawbacks in design.
August 27th, 2008 at 6:22 am
Andrew Farah said “The RPMs of the engine aren’t going to follow your throttle pedal as they do in a typical car. It will run at some various RPM speeds.”
It’s probably not the same, but it reminds me of times past flying aircraft (i.e. Navion) where the engine operated at a constant RPM while the propeller speed was dependent upon the manifold pressure setting.
August 27th, 2008 at 6:24 am
Dan Frederiksen # 63
Best ICE option from available ones for GM. They tried smaller one but unsuccessfully. Problems when starting engine and vibration.
August 27th, 2008 at 6:28 am
First, I’m sure the Volt will have plenty of onboard computing power. With that, the ECM (electronic control module) can look at your average power consumption over a recent period of time (are you in the city going from stoplight to stoplight or on the highway doing 95 mph).
With this info, the ECM will determine which of the pre-determined power levels would be appropriate for the ICE. The goal being to match or slightly exceed your average power demands. See this previous thread:
http://gm-volt.com/2008/07/26/gm-has-decided-on-the-14-l-4-cylinder-engine-as-the-range-extender-for-the-chevy-volt/
Note in this curve supplied by GM, the ICE comes on and provides slightly more power than needed, so that the battery is gradually replenished. Once the battery reaches about 35% SOC, the engine may shut down.
As we know, it is best to operate an ICE when it is hot, and it is better to operate it for an extended period of time and then shut it down for a period of time, versus starting and stopping the ICE on a frequent basis. Therefore, the goal is to operate efficiently for longer periods of time.
The following link is for a GM 1.6 L engine from the 2008 Aveo (close to the new 1.4 L).
http://media.gm.com/us/powertrain/en/product_services/2008/HPT%20Library/Fam%201/2008_16L_I4_L91_Aveo.pdf
At a nominal 1250 rpm, this engine can produce a nominal 16 hp (12 kW). This engine setting might be used for low power consumption driving such as in the city or moderate speed highway driving.
For driving highway speeds of 75 mph with full AC, 12 kW may not be sufficient, so the next engine speed might be a nominal 2000 rpm. At this setting, the engine can produce about 34 hp or 25 kW.
For Autobahn speeds or long hill climbs, full power may be needed, so the engine would go to about 3200 rpm and generate 67 hp or 50 kW.
So the ECM will likely trend your energy consumption and determine which of the preset generator speeds (i.e. power) to choose that best meets the demands of the system, yet doesn’t rapidly charge the battery pack and lead to frequent ICE starts and stops.
I’m sure GM is also selecting several points of operation so that the ICE can be optimized for these points.
August 27th, 2008 at 6:33 am
“Isn’t that special”. How is a family of four with a total income of 52,000 going to afford an automobile costing 35-40,000??
Here’s the answer,…..Answer) They’re Not!
Only the upper middle class and rich will be able to afford the Volt. The car must come down to 22-25,000 in order to be a viable, life changing automobile. The “middle-middle class” in this country is doomed at present.
The rich won’t even want such a vehicle, until it says Lexis, Cadillac,
Mercedes, etc. How many middle class are actually left in the U.S.?
August 27th, 2008 at 6:49 am
FBerry #74
I see a lot of people complaining about the price of the Volt. And you are correct, the Volt will probably be expensive in the first few years, and production will be limited. Advanced technology doesn’t have the reputation of being cheap.
However, many people in the income bracket that you mention don’t purchase new cars, as the best value in automobiles can usually be found in used cars 2 to 4 years old. I expect the same situation for the Volt. As the next generation of the Volt is introduced, it will likely have better performance and lower cost, driving the price of used Volts into the $15 to $25 K range.
With reasonable battery life remaining, these vehicles will represent excellent value for the 2nd owners.
August 27th, 2008 at 6:54 am
There can’t be a direct connection between the generator and the motor; you couldn’t regulate ground speed except for finely adjusting the generator, and that’s not happening. Most likely there will be a power buss connecting the battery, the motor, and the generator. Power controllers will separate the buss from each of these three devices.
A power controller between the generator and the buss will decide how much power is put onto the buss. A power controller between the battery and the buss will decide how much power is put onto the buss or sent back into the battery. A power controller between the buss and the motor will regulate taking power off the buss (ground speed) or putting power onto the buss (regenerative braking). The big trick is writing the software to regulate this network of smart controllers.
They will have to/want to dump excess generator power to the battery, hence the buffering concept. If the generator is producing slightly less power than required, they will have to tap the battery. When regenerative braking occurs, they will have to dump it to the battery.
None of this variable speed debate addresses the need to build up a full charge in the battery as you approach the foothills of a long mountain incline. Remember, the motor is roughly twice as powerful as the generator. Without storing up a charge in the battery it will be like trying to climb a long hill with only four of your eight cylinders; who would choose to do that?
August 27th, 2008 at 7:05 am
That’s great about the generator. My question is… What is the gas mileage use when the gas generator is needed. Is it worth it to purchase the car for only 40 miles? Going on regular 200 mile trips I need to know how much gas I’ll be using.
August 27th, 2008 at 7:09 am
“Isn’t that special” …
Why yes it is.
The 1st version of the car is not meant for a family of 4 with an income of 52,000. May I suggest a 5 year old used Car and a good mechanic for a family in that situation.
The median income of the top 100 counties in America are all well above 52K. Perhaps the volt will be better suited to these people and not the hypothetical family just above poverty level.
The first version of the volt will be for people who have the money and either want the first electric on the block or have some real concerns about pollution or money sent to the Middle East for oil. There are plenty of these people in the US and yes, for these people, the car will be special.
Watch and see. GM will sell everyone they can make.
With your used car, you will still benefit from the Volt. Cars like the volt will slowly reduce our need for oil and let the speculators know that Oil is not the only game in town. A reduction in demand will lower the cost of oil and gas for everyone. Electric cars will also help clean the air (the car will be 20% nuclear powered). The cars will also become relatively cheaper in the future as battery developments continue.
So yes, the car is special. It is a serious attempt to begin mass producing an electric vehicle which will be affordable to many (not all of course).
August 27th, 2008 at 7:23 am
#74 FBerry
“Isn’t that special”. How is a family of four with a total income of 52,000 going to afford an automobile costing 35-40,000??”
I am not trying to be insulting, or agravating, but posters like yourself, are willing to toss crap out like it is gospel, and ZIP, ZERO,NADA to back it up..STATIK will be a naysayer and at least post links supporting his position.. so with that in mind.
Please tell us the source for the MSRP for the VOLT?
Never mind the speculation, that is just crap, never mind the quote of” the volt will cost $xxxxx.xx” likely the execs are talking what it costs GM to build.
Tell me the source for the FINAL SELLING PRICE BEING 35-40,000.
Sorry..cost is not selling price… While it makes no SENSE for GM FINANCIALLY to sell the car at a loss, it can makes HUGE sense ECONOMICALLY.
I’ll explain my reasoning…They NEED the masses to buy, to lower the price with economies of scale, and to gain market DOMINANCE!, THEN… as costs to buid decline, they will make money, and with market dominanace, they will sell more. GM is burning cash anyway..it would cost them 1 billion, to shave to 5 grand off the first 200,000 VOLTS. Never mind incentives. Toyota lost money on the Prius int he first few years.
And GM launching the Provoq will help offset costs (Another smart move, as it returns Caddy to status car classification, luxury, AND green!) if the costs are similar to a volt, you can bet the farm GM can recover some of the 5G losses on the Chev version…
So I ask.
SHOW ME WHERE YOU HAVE DEFINITE SALE PRICING FOR THE VOLT.
August 27th, 2008 at 7:26 am
BillR-
I think you’re on the right track. I don’t see much of a need for more than about three speeds either.
I can see GM letting the ICE drop to idle when stopped simply to appease all the knot-heads out there that think they need “shift points” and an idling engine when stopped at a light. It would really kill me if they built in “shift points” though. People need to get past all these pre-conceived notions of how a car should drive/feel/sound. A modern 6-speed automatic is so smooth that the shift points are almost unnoticable. That is the goal for a design engineer. Silly to build something in, that we’ve been trying to get rid of for years.
I also doubt there will need to be any provisions for heating/cooling the batteries when not in use. I’m sure one of the design criteria of the batteries is to have a maximum rate of self discharge at various temperatures (when not in use).
Getting off on a tangent here but I wonder how much heat these batteries will produce. I suspect the “problem” is that the heat they produce is not high enough. By that I mean that heat transfer is much less efficient when the thermal gradient is small. I.E. cooling the batteries from 120F to 80F (with an ambient air temp of 70F) would require a much larger radiator (or equivalent) than cooling from 200F to 160F….like a normal car engine.
August 27th, 2008 at 7:30 am
Here is something to consider. As most of us know, if an engine spins a generator at different fixed speeds, the output voltage of the generator will be different at each of those fixed speeds (the higher the rpm’s, the higher the voltage). Does that mean the Volt will require a different voltage at a different condition? If yes, why?
August 27th, 2008 at 7:58 am
I also would like to hear more about the HVAC details. There is just no selling or buying this car in certain climates if the HVAC system is not up to par (unless you live in CA). I also live in WI and there are mornings were there is 2 feet of fresh snow on the ground with a -20 temp.
This brings up another point has any consideration been given to how this car handles in the snow? Or issues with water and snow getting up in the engine compartment and then re-freezing (there has been plenty of times that I have driven through snow 2 feet deep with my 300C all of the snow is pretty much stuffed up in the engine compartment)? Are all of the electrical components going to be water tight (I ask this because it seems from everything we have heard that these components will be house in the engine area)? This also applies to anyone who has had to drive the large amounts of standing water on an overflowing road. Or how about the effects road salt will have on the components in the car? I know these things may sound trivial but if you live in a state where there is snow these things make a big difference.
August 27th, 2008 at 8:00 am
One question I can not seem to find the answer to. They say the volt has no grille, but how does the gas motor get cooled off?
August 27th, 2008 at 8:03 am
#74 bob Says: “That’s great about the generator. My question is… What is the gas mileage use when the gas generator is needed?”
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50 miles per gallon.
August 27th, 2008 at 8:08 am
solo Says: @9
I bet the Volt’s engine noises (ICE, electric motor/generator whine ETC) will be well insulated. Electric motors/generators have an inherent winding annoying noise. I believe GM will address those noises by using the front lower part of the grill, to allow air to a sound insulated duct leading to the electric motor and exiting to the rear of the car to muffle those sounds. That lower part of the grill will also branch out to the ICE compartment and do the same (silencing the ICE and it’s generator whining noise) and also exit to the rear.
Those are just my thoughts.
August 27th, 2008 at 8:12 am
#80 brady turley asks: “One question I can not seem to find the answer to. They say the volt has no grille, but how does the gas motor get cooled off?”
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The Volt will have 2 grills.
The upper one with the Chevy logo is mostly fake, but will let in small amounts of air around the edges. This will generally cool all components under the hood.
The lower one will have air baffles that guide the air to the gas engine’s radiator as efficiently as possible.
This info comes from previous articles from Lyle as well as the online chat with Bob Boniface.
August 27th, 2008 at 8:18 am
COST
More important than a steep sales curve at introduction is a strong and durable demand curve. At introduction, quality must be the overriding objective for first-of-a-kind products like the Volt, not sales. Given the nation’s focus, there will be no shortage of interest and awareness.
Real Volt sales will (or will not) appear a few years after introduction assuming:
1. GM has succeeded in making it clear whether it will indeed be the leader in this vehicle category,
2. It become evident that the concept is really the kind of product you should buy,
3. And only then, once the price falls to your level.
Initial sales levels will not be important but quality, validation of the supplier and the approach will be everything.
If that forces an approach that forces introductory prices to be much higher than are acceptable to most, it won’t be a showstopper. As long as the prospect of acceptable prices from GM is evident and all other aspects are successful, GM should be able hold onto its leadership role in this new category.
MULTIPLE FIXED RPMS
Questions:
1. Is it possible that starting and killing the ICE every few minutes would cause sufficient thermal cycling of the ICE to reduce its life? If that’s the case then it does seem to make sense to optimize the ICE so it can run efficiently (and run long enough) at a several RPM points
2. How much energy is lost just starting an ICE? Is it significant? What’s the results of cycling the catalytic converter every minute or two? If these are problems then many dozens of starts per hour instead of just a few may decrease overall system efficiency.
3. (Mentioned already a few times) Does the optimum charge rate vary with battery temperature? If so that would also argue for more than one optimized RPM.
August 27th, 2008 at 8:19 am
It is likely (just guessing) that the RPM will have nothing to do with the current demand from the driver. This changes all the time… from very low while at a stop light too instantly high demand on ensuing take off. It is possible that the ICE will run at 3 speeds. The higher rpm when the battery SOC reaches 30%, midrange rpm when the SOC reaches 32.5%, low rpm when the SOC reaches 35% and turning off if the SOC reaches 40%
Current car electric demand could be averaged over the last 4 minutes and the ICE rpm set to closely match that. Sort of a time weighted average sort of control.
August 27th, 2008 at 8:19 am
#38 Belloc,
#39 Firefly,
#44 Mike-o-Matic,
#51 Viscount Nik,
#79 Scottie,
We heard late last year that the HVAC system will be all electrical and will not depend on the gas engine in any way. Also note that the power steering is all electrical.
We also later heard that designing and sourcing these components for maximum efficiency will take time, so even if the battery was ready today, the Volt would still take until 2010 for the HVAC systems.
This information came from Lyle’s interviews and videos with GM engineering managers on this site a while back.
August 27th, 2008 at 8:32 am
#50 Bill W.,
#71 FBerry,
#72 BillR,
#75 nuclearboy,
#76 mitch,
#84 jwcrim,
We heard here:
http://gm-volt.com/2008/08/19/gm-ceos-best-guess-volt-will-be-priced-in-mid-to-high-30s/
that the Volt will probably cost “mid to high 30’s”.
Let’s say it’s $37,000. Whoever gets elected, it’s likely U.S. government will approve tax credits for plugins based on KWh. If the Volt got a $7K tax credit, this would put the adjusted price at $30K.
This would help a lot with initial volume. As sales volume ramps up, costs should decrease further.
August 27th, 2008 at 8:35 am
It’s funny how most of the people on this blog are trying to be armchair engineers…. Don’t you think that GM has several people on these (and more) topics? An automobile that has billions in development costs and can be a game changer will have to be ‘right’. Quit worring about making it up Pikes Peak or whatever mountain and relax and be happy that GM is building this type of vehicle. Whats funny is, GM or the aftermarket will have software programs that will allow you to tune this vehicle to your liking. Bottom line is, it will work right when it comes out, or people will be complaining enough that ‘fixes’ will be made. Just don’t let Microsoft have a hand in it or the ‘update’ may disable it for days!!!
August 27th, 2008 at 8:37 am
#52 EV,
#59 Mark,
There are lot’s of issues with pure EVs:
1) What happens when I forget to plug it in one night? Given my typical frame of mind when I come home at night, this is a lot more likely than running out of gas.
2) What if someone calls and invites me to a party tonight, and its over 20 miles away?
3) What if I plug in it, but it’s raining, so the GFI trips?
4) What if I have it on a timer to take advantage of night-time rates, but the timer fails?
5) What if it gets really hot outside and there’s an overnight blackout?
6) What if I plug in the car, but the plug on the other side of the cord has fallen out of the wall?
7) What if my brother has a serious accident and is in the hospital, and I don’t want to waste time renting a car?
The list goes on…
There are way too many what-ifs for me to ever consider a pure EV.
August 27th, 2008 at 8:39 am
Good Morning:
News up date for sight, those of you that have worried about electrics being to quiet.
Yesterday the California legislation voted to pass a law that ALL electric autos must have some type of noise emittance for the blind.
I guess drivers do not have to take any responsibility to drive carefully !!
God Bless America.
Tom
August 27th, 2008 at 8:44 am
For those of you talking up your current/past car that gets 45 mpg, remember the VOLT will get a WORST CASE 50 mpg. If you drive 90 miles a day (which is ALOT), your going to average 90 mpg assuming you plugged in every night. Granted you have the electrical cost for recharging, but depending on where you live that should not be a huge cost. And for most of us..75% of our daily driving is ~ 40 miles. I will most likely have to add fuel stablizer because a tank of case may last me 2 months or more. I’m expecting to average more then 100 mpg personally, based on my driving habits.
I wonder about oil changes…? I was thinking you may change oil based on Hours of ICE similar to my boat. 10,000 - 15,000 miles on a VOLT may have only seen 5,000 miles of ICE usage. Yet another small but nice savings.
I hope they put an ICE OFF switch. Only because if I’m within 5 miles of my house and at 30% battery, I would prefer to go on electic. Given GM already allows the battery to go under 30% for heavy hill climbin as long as you don’t drain the battery to 0%, I would think letting it get to 20% is of minimal impact to battery life..???
Can’t wait to get my VOLT…..
Todd
August 27th, 2008 at 8:46 am
#22 Ian Porter Perth , you are right . I can think of at least three rpm that is significant for an ICE.
First the rpm that gives the most most fuel efficiency , which will be used for maintaining the near 30% SOC when the Volt is cruising at normal road conditions, after the 40EV mile
The second is the rpm at which the ICE gives the maximum torque. It could correspond to the the Volt climbing a gradient up and
the third rpm is connected the maximum power of the ICE which naturally will be its highest rpm. I hope this will correspond to the of highest speed of the Volt .
The pedal of Volt , will naturally be linked to the computer and not to the ICE direct.The computer will select the rpm of ICE, and the source of power ,whether it is from ICE, battery or from a combination of the two.
After the first 40 EV miles,a series of variables will come into play depending on the driving condition, though an Engineer,I find it very complicated to grasp the whole scenario. That is why Lutz, some time back , had talked about rolls and rolls of computer coding, as one of the challenges they were facing.
GM has not come out with many critical technical information relating to this stage,either they may not divulge it for obvious reasons,or they may not have taken a final call on these variables.So for the time being we can only assume that these are the probabilities and discuss
August 27th, 2008 at 8:51 am
Cool that would be just awesome for California to not get any of the Volts due to their stupid laws. Oh how that would make my day!
Now if we in the Oil producing states could just charge states like California and Florida extra for any oil or gas they buy from us.
August 27th, 2008 at 8:55 am
#87 Dave G
From your link
“What will it sell for?
We initially hoped we could get it for a very good price, lets say below $30,000. Its going to be more expensive than that, the first copies.
35?40?
We haven’t finalized it, it wont be as high as 50 but it’ll be in the mid to high 30’s is my best guess.”
My point if you reread is Where is there a FINAL price..this specifically says “GUESS”
So it is still fluff…GM will not release..all this can do is generate debate here and keep the competition guessing..Toy can say…Hmmm seems gm new EREV will be high 30k..we can price the prius say 35k and still dominate..GM final price lower…Prius killer…
Still waiting for PROOF!
Mitch
August 27th, 2008 at 8:59 am
I hear a lot of talk about a deisel. I would not like a deisel the smell of that fuel is just to much for me. It gets on everything every time you fill up.
How about the best of both? HCCI Maybe the ICE will use the HCCI tech?
August 27th, 2008 at 9:04 am
“It’s funny how most of the people on this blog are trying to be armchair engineers”
They are right to do it.
There’s is danger that we’re losing some of our trademark interest in the nuts and bolts. My father was born 1895 in Detroit and saw the family horse give way to the first cars. He and everyone else made basic changes to their early cars to make them more useful.
In the 1890’s my great grandfather was a hobbyist who liked putting naphtha engines in boats. He traded parts and tips with other tinkerers including Henry Ford when Ford was a young chief engineer at the Detroit Edison Co. I’m sure they were all guilty of reinventing the wheel.
I’m encouraged to see all this interest at the nuts and bolts level. We complain that young people are no longer interested in technology. That interest has to begin somewhere.
August 27th, 2008 at 9:05 am
Obviously the RPM’s of the genset should match the load demand, the demand is determined by the charge level and rate of discharge.
I would envision The RPM’s will be a series of steps or ranges based on load demand. On sound levels, I heard about a Prius owner installing a loud straight through exhaust system in hopes of gaining efficiency, with the on and off cycling of the engine the resulting sound was that of a cow bellowing over and over again.
August 27th, 2008 at 9:06 am
I haven’t had time to read all the comments, but I wanted to address one question I had been thinking about. I assumed the ICE generator would run at various speeds from the start. The thing that I wonder about is: If the ICE generator is running at a high rpm and you bring the car to a stop, will the engine reduce the rpm speed to a level where it does not sound like the engine is just running away with a loud roaring sound? That would seem to be a place where the computer should put the engine’s rpm at it lowest level or turn it off completely until you start up again.
Does someone have any information on this?
August 27th, 2008 at 9:07 am
I find it hard to believe that the VOLT chassis and a super economical engine can’t get 50mpg without the extra weight and systems of the electric drive train.
I understand this is a super hybrid without a direct drive train link, I’ve followed the VOLT since the beginning and I’ve been a supporter.
That said.. this car seems to be a poor compromise because of the huge fixed costs of batteries, battery technologies that aren’t mature enough yet, increased weight, and long term maintenance of that complex electrical system.
I’m still a VOLT fan.. it’s an exciting concept BUT, Since you’re still using gasoline why not develop pure gas 50+mpg vehicles at a lower cost, lower weight, and lower risk (for GM and the owners)?
Can you imagine how simple a VOLT would be with just the small gas engine?? 50mpg has to be obtainable.
(ok ok.. all that said… I’m just expressing my opinion so please don’t pile on. )
August 27th, 2008 at 9:16 am
#90 Tom
“Yesterday the California legislation voted to pass a law that ALL electric autos must have some type of noise emittance for the blind.”
So, this means that the Volt will have to make noise when the ICE is not running and the ICE can’t be too muffled when is it running. Hmmm… I wouldn’t mind as long as you can customize the sound, like a tie fighter sound…
August 27th, 2008 at 9:20 am
#54 Texas,
#73 hermant,
#78 Joe,
I believe GM said last year that the ICE/genset, battery, and electric motor would all be on the same DC bus. In other words, all 3 are wired in parallel. For this discussion, the generator would include the diodes to convert to DC, and the electric motor would include the inverter/controller.
So there are many possible flows of electric current:
1) The ICE/genset can supply electric current directly to the motor, effectively bypassing the battery.
2) The battery can supply electricity to the motor (EV mode).
3) The motor can supply electricity to the battery (during regenerative braking).
4) The motor and ICE can supply electricity to the battery at the same time (when regenerative braking begins).
5) The ICE and battery can both supply electricity to the motor at the same time (when accelerating or going up a steep hill).
6) The ICE/genset can supply electricity to both the motor and to the battery simultaneously (to recharge back to the customer depletion point after accelerating or going up a steep hill).
Conceptually, I think of this like water. The battery is a big bucket. The ICE genset supplies water. The motor can drain water or supply water.
My guess is that the generator / alternator will work similarly to what we have in our cars today, only bigger. The alternator is designed to output a specific voltage.
When the battery voltage is high, the generator output voltage will be about the same, so there will be no load on the generator. With no load, ICE RPMs will tend to increase, so the ICE controller will let up on the throttle, or perhaps turn the ICE off.
When the battery voltage gets lower, there will be a difference in voltage between the alternator’s output and the battery, so current will flow and the load on the ICE will increase. With increased load, the ICE controller will increase the throttle to maintain the desired RPM.
So I’m not sure there would be a need for power controllers on the bus, except perhaps a switch when the ICE is off, but I could be wrong here.
August 27th, 2008 at 9:26 am
Don’t let perfect get in the way of good. Do make the Volt 5 star for crashes…a major GM failure needing correction now. Learn from NASCAR about crashworthiness vs weight. Use high strength foam composites to add strength and insulation so HVAC demand is reduced. Ease up on the ubiquitous GM gizmos and help Hughes devices in favor of rock solid design. Use high quality chips…the debacle of earlier stalled, stuck on the side of the road GM lemons needs over now. And put a really good, corrosion proof exhaust that is quiet on the ICE.
August 27th, 2008 at 9:27 am
Aspherical #100
It has been sent for Governor Schwarzenegger’s
signature, I have no doubt he will sign it.
I’m going to date myself but lets go for the old clothes pin with a playing card attached so the spokes can go clickety, clack as we go down the street.
Tom
August 27th, 2008 at 9:31 am
#99 John Says: “Since you’re still using gasoline why not develop pure gas 50+mpg vehicles at a lower cost, lower weight, and lower risk (for GM and the owners)?”
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The idea of the Volt is not to use gas at all. If you drive less than 40 miles per day, you will never use gas.
If you drive significantly more than 40 miles per day on a regular basis, you might be better off with a VW TDI or Toyota Prius right now, as these both get around 50mpg and cost less than the Volt.
Yes, it would be nice if GM offered cars like the VW TDI or Toyota Prius right now, but as the cost of batteries comes down, the difference in price between the Volt will be less, and it will become a non-issue.
August 27th, 2008 at 9:34 am
I hope they use a heavy duty muffler and lots of sound proofing materials so the passengers don’t even know when the IC engine kicks in and the rpms increase. Maybe just a little vibration is all they’ll notice. Make it so quiet that you barely hear the tire noise as you go faster. I think it will be weird for most people to drive a car so quiet at first, but people will get used to it and wonder why they drove such “noisy cars” all these years.
If for some reason, people want to hear some sort of noise from the electric motor for throttle feedback, maybe GM can design some sort of setting in the touchscreen panel to do this. It would be in sync with the electric motor as it accelerates the car. As long as it only plays INSIDE the car, that’s fine with me. If they are nostalgic for IC engine cars, people could download and install whatever engine soundtrack .mp3 they want. Camaro, Vette, Porsche, Ferrari … whatever.
August 27th, 2008 at 9:39 am
#95 Starcast Says: “How about the best of both? HCCI Maybe the ICE will use the HCCI tech?”
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GM has ruled out HCCI on the Volt, at least for the first generation. Lyle wrote an article about this last summer:
http://gm-volt.com/2007/08/28/breaking-volt-combustion-engine-still-undecided-wont-be-hcci-at-first/
August 27th, 2008 at 9:42 am
#90 Tom M Says: “Yesterday the California legislation voted to pass a law that ALL electric autos must have some type of noise emittance for the blind.”
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Thanks for the info. I was expecting something like this.
Do you have a link? I’d like to know more details.
August 27th, 2008 at 9:47 am
We also have a device in the center of the steering wheel, it’s
called a horn !!
Unless the VOLT is not going to have one?
Tom
August 27th, 2008 at 9:49 am
#76 Mitch
With a release of only 10,000 vehicle during first launch, I doubt the price for such a vehicle will be low.
If GM were able to make many more vehicles, I expect the price to be much lower and even be as you suggest. But, I’d be willing to bet that the price the first year will be well over $40,000.
During the second year with a 60,000 vehicle release, and beyond; I see exactly what you suggest.
I do not have an MSRP, nor do I have GM authority. The opinions expressed above are mine and are subject to change with additional information. Vehicle release numbers were obtained from wikipedia and from addition interviews and releases.
~Bob
August 27th, 2008 at 9:52 am
To: Dave G. 3107
It was on Fox News last night. I think Bill Bennett also mentioned it on his show.
Tom
August 27th, 2008 at 9:52 am
Forget the Caddyvolt, we’ve got spy photos of a possible minivanvolt!
http://jalopnik.com/5042280/2011-chevrolet-tacuma-minivan-spied-testing-hunting-down-soccer-practice
These are spy photos of a European Chevy Minivan (the Tacuma) that is supposedly being built on the Delta platform and is scheduled to debut in 2011. If GM is going to use the volt platform in a minivan like this, I will buy this vehicle even at $40K! I would much rather have a van than a passenger car. Even at 30 miles AER, I could do all my weekly driving without using a drop of gas and then have my van for weekend trips with the family. I just hope it’s not going to be a Europe only minivan!
August 27th, 2008 at 9:56 am
109 Bob
I agree.. but I will bet the first edition (10 k mass protype really) will not be sold at all, lease..look for sales once the bugs are out..2011 edition. It would be a condition that the leasees would likely swap the cars out every 3 months or so, so GM can evaluate information from Data acquisition instruments that will be installed inthe forst 10k. units. after 9 months, you keep it as GM will have the final data for manufacturing, mass production begins and sales start.
My 2cents
August 27th, 2008 at 9:59 am
I thought that it would run at a preconfigured speed, I know that I get a better gph when my engine is running at a steady speed instead of the drag of going up hill and the slow downs and passing speeds etc. It only makes sense.
I’m looking forward to the experience. Right now I’m trying to find In-Wheel motors to upgrade my Eldorado.
August 27th, 2008 at 10:00 am
#85 omegaman66 Says: “Current car electric demand could be averaged over the last 4 minutes and the ICE rpm set to closely match that. Sort of a time weighted average sort of control.”
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I think it will need to be much more dynamic than that.
Remember that the idea is not to charge or discharge the battery significantly. Charging and discharging adds wear to the battery, and also loses efficiency in the electrical / chemical conversions.
There will need to be some averaging, but I would think 5 seconds is more appropriate.
August 27th, 2008 at 10:13 am
#57 matt,
#60 Dan Frederiksen,
As it turns out, the weight of the Volt doesn’t seem to have much effect on efficiency. This has surprised just about everyone. I guess regenerative braking is a big deal.
August 27th, 2008 at 10:21 am
Over 100 posts before I ’stick my toe into the water’…amazing.
I guess this is another topic that is more technical in nature, and has little to do with the EV component/progress/pricing, etc…so I file it under interesting to know, good to pass the time by…but not overly exciting to post on.
I just wanted to touch on the ‘median’ income and it’s relation to the affordability of the Volt, thats more of the stuff I like, lol. And it’s topical, US Census bureau just yesturday released the median household number for 2007.
As FYI, the median HOUSEHOLD income (as at the beginning of 2008) in the US was $50,233. The median income per INDIVIDUAL (all persons over 18) in the US was $25,149 in 2005. (Fulltime - 45K/men, 35K/women)
http://www.census.gov/Press-Release/www/releases/archives/income_wealth/012528.html
http://pubdb3.census.gov/macro/032006/perinc/new02_001.htm
More important than this is at what point does a average household income equate to a resonable level to expect the Volt to be a viable choice, for this example, lets say 45K (40K MSRP, delivery, taxes, cost of insurance, etc.)
For individuals, lets say that income number is $100,000. 94.37% make less than that amount, leaving obviously 5.63% of the market more than capable of purchasing.
http://pubdb3.census.gov/macro/032006/perinc/new01_001.htm
For household incomes, lets set the bar at $125,000. 92% make less than that amount, leaving 8% of the market.
Representationally this equates to 10,813,000 individual incomes and 9,050,000 household. Approximately 85% of those individuals are contained in the household number, so that gives us a pool of about 10,670,000 customers…or 3% of the population.
August 27th, 2008 at 10:21 am
#113 Watts Enthusiate Says: “Right now I’m trying to find In-Wheel motors to upgrade my Eldorado.”
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http://www.pmlflightlink.com/motors/hipa_faq.html
August 27th, 2008 at 10:23 am
Leave it to the People’s Republic of California to legislate on something as stupid as ADDING noise to cars… As it is now, you can’t hear an ICE Honda or Toyauto unless you’re standing right next to it.
August 27th, 2008 at 10:23 am
#112 mitch
I didn’t think about the lease option… and that may be the way GM will go. With a technologically new car such as this, this makes great sense. But I still expect a high price!
“GM indicated that “GM’s game-changing EREV technology should be treated as a low-volume application … during the 2011-2015 timeframe.”
Hmm, that phrase ‘low-volume application’ screams to me ‘lease’. I’m surprised I didn’t notice before.
~Bob
August 27th, 2008 at 10:28 am
Further to last post (I like to break them up to hold reader interest), lol.
The median household income is now actually falling. The increase for 2007 was 1.3%, however you have to strip out inflation/cost of living to get a accurate number…inflation for 2007 was 2.85%. Incomes actually fell by 1.5%.
However, more important to the ‘income’ numbers (which are fun to play with), is the affordability factor. Most people live close to (if not higher) than their means. A high income is not as good a indicator of potential customers as it was even a few years ago. The inaccessbility of the credit market, coupled with higher premiums on converting mortgages has made a good number of incomes in this bracket completely underwater.
Likewise, some people/household which make under my arbitrary 100K/125K number ‘could’ afford this vehicle if they live well under their means or it is a ’special purchase,’ meaning they are devoting a misproportional percentage of earnings/savings to it.
…and finally, (yes I will shut it now). Historically, GM had leased over 40% of vehicles with a price greater than 35K. I’m not saying all that business goes away, but the next few months will tell the tale on how GM copes with losing the lease business. (Right now, that is GM’s biggest concern as 21% of al US sales are leases and 43% of all Canadian sales are leases).
That being said, I’d say the Volt if it where offered North America wide would be a realistic purchase for about 2% of the population.
August 27th, 2008 at 10:34 am
I wouldn’t be surprised if GM built an E-flex car in the next 10 years that lets you use natural gas as the fuel for the IC engine. After watching his new commercial, I think T Boone Pickens should be talking to GM about this. I think the kinds of people who buy the Volt will be open to new kinds of fuels for the IC engine if it is fairly inexpensive and readily available. Gotta admit, even though it emits CO2, natural gas is a much cleaner burning fuel than gasoline.
I think one of the main reasons people that buy E-flex cars will be open to new fuels is because they usually only have to fill up maybe 5 times a year. They might could sell the natural gas for E-flex cars at Home Depot or Wal Mart like they do propane if the oil companies don’t want to build the pumps for it. On long trips, you could use your GPS map technology to locate places that have natural gas.
That’s what’s great about E-flex cars. The fuel is kind of an afterthought for most people unless they are making a long trip. If the fuel is available almost everywhere and it is relatively cheap, people will use it. If T. Boone Pickens wants to get people to use natural gas, he’s going to have to work on infrastructure and all that … just like with ethanol and hydrogen, etc.
Argonne Labs is developing IC engines that will burn lots of different fuels. Methanol, butanol, corn ethanol, cellulosic ethanol, gasoline and who knows what else. Maybe this “omnivorous engine” can be designed to use natural gas too. As long as the fuel will explode optimally in the cylinder it should work. The controls for the engine will adjust the combustion settings according to the fuel used somehow or another.
Bottom line, I want to be able to have CHOICE when it