AND 
Exclusive: The Engineering Challenges of Volt Generator Mode
After the Chevy Volt has been driven 40 miles on electricity, the gas-powered generator turns on supplying electricity along with a buffer in the battery that the electric motor needs for continued operation. Though GM has been developing this function for a while they have not shown it publicly.
I had a chance to discuss this extremely important and unique mode of Volt operation with Volt executive Tony Posawatz who explains what functions GM still has to work on.
When the generator goes on will it come on gradually?
We’re still playing with it. The initial transition we like very much, it is almost imperceptible. We want to tune it and exercise it more for production readiness, but we have an algorithm of software that feathers it in so that its almost imperceptible.
To many people it is imperceptible, to those that are a little bit more tuned in…Frank (Weber) says its not quite perfect, he wants it so that no one can hear it.
That transition isn’t handled in most hybrids that well, particularly when you stop at a light an the engine shuts off and you get that shudder. We have this benchmark we set, that we’re going to blow them away.
By the way, our motor is so much bigger than theirs, the power output of the electric motor, that effectively is the starter. We’re in the point of tuning it and it’s a very very complicated tuning exercise if you want to make it perfect.
It’s a balance equation. Here lies the challenge. You will get some feedback from the car about its environment, or the road load. You’re demanding so much power from the car, and you will get some feedback. That’s one input that you have to be able to respond to to deliver the right amount of power. The other aspect that we have to play with is this area of OK when I respond to it, the engine generator will run in different modes or RPMs. How do I transition from mode to mode, a timing issue, do I smooth it, do I try to react immediately to that response? If I act immediately to that response how will customers receive that? such as a wild of swing of RPMs?
There’s the responding to the car’s demands based on the loads number one, then there’s the affect on the customer, we want that to be really pleasant. The transition to charge sustaining, we’ve got that down, it’s the operating in the very different modes we’ve got to figure out. The next leg is making sure the engine is running the most efficiently that it can.
Generators are typically run at a sweet spot that’s very efficient. We could do that. The question is, does the amount of output of power that results from that manage or balance with what the car needs?…hmm how do you do that? That’s another reason we have this battery buffer reserve.
How often do you turn the engine off and on is another question. These are the factors that have to be balanced.
People ask why can’t you show it to me? Because we want it just right.
This requires a lot software. The other interesting challenge is the regulatory issues. Theoretically you could run the engine enough to build a surplus of energy. The regulatory guys are not going to let us do that, it’s a five legged stool.
Is the EPA sitting on a committee while you engineer the car?
This is more CARB than it is EPA. EPA is interested from the perspective that they need to understand how to label it. CARB really doesn’t want you to burn fuel if you don’t have to.
The message on charge sustaining mode is we’ve got a good beat on it, its the four or five things that have to be balanced together and the team needs time to work.
Will the engine rev higher when you step on the accelerator?
Yes, but the question is, if I have a little battery reserve at that time, do I turn the engine on right away to follow that or is it a smoothing function?
Also lets say you just went up a monster hill and the engine feathered up a little to support you and you get to the top of the hill and hit a light. Should the engine keep on running to allow you to recover or do you turn off the engine because the customer expects it too because they’re stopped at a light?
Technically are these difficult challenges? No. Its hard development work balancing the calibration of a lot of software.
August 17th, 2009 at 6:51 am
I have been in a Prius when the ICE turned on.
It was blatantly obvious. I will be nice to have a silent mode on the Volt.
And being in IT, the more software code the more chances for bugs. It should be interesting.
(Quote)
August 17th, 2009 at 6:51 am
As an engineer I appreciate the complexity of the systems engineering going into this car. But as someone who’s been following the volt for a while and who currently drives a prius I’d be more concerned with operating at the sweet spots and trying to achieve the best MPG’s possible while still having a smooth ride. I don’t think they should kill themselves to make it “SOUND” like an EV all the time. Let the engine do what it needs to do to get us above 50 MPG in RE mode. I think that should be the goal.
BTW – Absolutely awesome article Lyle. This is what keeps me coming to the site
(Quote)
August 17th, 2009 at 6:56 am
It’s interesting that so much time is being spent making the RE experience as similar to current ICE responses as possible.
(Quote)
August 17th, 2009 at 7:00 am
I concur. I hope that this level of refinement and attention to the details will distinguish the Volt from the knock-offs ( especially those from China) that are sure to follow.
Also, it makes me wonder how Fisker is approaching it, given that their timetable seems more agressive than GM’s.
(Quote)
August 17th, 2009 at 7:02 am
GM…do not forget the KISS rule of engineering.
(Quote)
August 17th, 2009 at 7:06 am
My 03 HCHI has the shudder and very limited start-stop capability. Going through a drive through, the engine may shut off once then keep running after the restart. Have to shut it off and restart with the key it if I want the silent feature, which is a nuisance.
Guess if I have a choice I’d have to agree with CARB. Using as little gasoline as possible would be my goal too.
(Quote)
August 17th, 2009 at 7:11 am
During acceleration from a stop, yes.
During other times, often you can’t.
Owners connect aftermarket devices (like ScanGuageII) because they can’t always detect when the engine is starting/stopping. Seeing the RPM reveals more than you can perceive by feel or sound… especially for the 2010.
It’s not a crude startup like with traditional vehicles. The generator motor is enormous compared to a starter. So when it spins the engine, the RPM is all the way up to idle speed and is held there until oil pressure is established before injection & spark. The result is a much smoother start.
(Quote)
August 17th, 2009 at 7:14 am
Yes, it is obvious, but it doesn’t matter that much. My friends that own Prii both get mileage in the mid to high 40’s, and getting off of oil is the point for many of us. I think Weber is letting perfect be the enemy of very good. Obviously, if you start the generator at a low RPM it will be very hard to tell that it is on. Just program the generator to increase from set point 1, i.e. 1200 rpm, to set point 2 at 2400 rpm, 5 or 10 seconds after the battery hits the customer depletion point so that there is no sudden increase in the background noise. And I really hate that term, customer depletion point… But my point is, allow the generator to slowly ramp up rpm, and ramp down when the car is at a stop, but don’t shut it off until the battery is the customer depletion point plus 5%. Then the car goes back to all electric mode for 3 or 4 miles, then the cycle starts all over again. Unless of course you are climbing Pikes Peak, or driving down I-95 at 90 mph.
I think GM is being tone deaf on two points, the generator mode is not going to be used that often by most drivers, and only the anal retentives are going to fault them for having an IVer that allows you to hear the generator, as long as it is programmed to follow driving cues, i.e. the generator slows at times the car is stopped. Second, they should have stressed the formula in the 230 mpge pitch, because they allowed the anti-Volt crew to pitch it as a GM lie, when in point of fact it is what the Volt will get using the EPA’s test cycle.
Those two points irritate me, but what I think GM really needs to do is get a dozen or so of these pre-production but post-IVer quality Volts out to people that blog about cars and/or the environment. If Lyle can get an electric Mini this year, he should be able to get a Volt by April of next year. Hundreds of thousands of people read this site, and hearing a real world evaluation of the Volt from someone who has built real world credibility would do GM a world of good. And by waiting til April GM would avoid the cold weather drop in efficiency up north.
(Quote)
August 17th, 2009 at 7:15 am
On this we can agree. Even if the operation of automatic transmissions seem beyond your ken.
Moving parts and software too? That must have you running off screaming.
(Quote)
August 17th, 2009 at 7:20 am
Well, that is one of the most candid interviews I’ve read about the Volt in a long time…if not ever. Excellent job Lyle and thanks to Tony for taking the time to explain the challenges. I would have to imagine the “tuning” aspect is doable but challenging and time consuming. I am glad to hear they are striving to make it perfect.
Maybe that test drive Statik requested just isn’t ready yet.
(Quote)
August 17th, 2009 at 7:20 am
My ‘01 Prius is terrible at shutting down and starting. I can’t wait to try the Volt and the better system.
Zel
(Quote)
August 17th, 2009 at 7:21 am
This is an interesting issue now they’ve made clear the ICE switches on at 30%. It does make one wonder when the ICE shuts off again. Does it cycle up to a certain point above 30% then shut off again?
(Quote)
August 17th, 2009 at 7:23 am
Only stuff that breaks when it shouldn’t.
And automatics aren’t beyond me.
I’m just not the lazy type.
(Quote)
August 17th, 2009 at 7:24 am
And I really hate that term, customer depletion point
_____________________
That’s not an official term. So, just stop using it. These are what SAE has defined:
CD – Charge Depleting
CS – Charge Sustaining
(Quote)
August 17th, 2009 at 7:27 am
John, I like your (SAE) answer better than Weber’s so I will adopt it in the future. Thank you!
(Quote)
August 17th, 2009 at 7:30 am
Why not always start the ICE running at 2200 rpm for 10 seconds? Then measure demand to find the sweet spot. Perform this simple measure/adjust function each few minutes. Add a default of 1200 rpm when the car pauses for more than 10 seconds. With a full stop of the ICE at a 20 second pause.
=D~
(Quote)
August 17th, 2009 at 7:30 am
______________________________________________________
I agree w/ #2 Gsned57.
Optimize MPG, KISS everything else…it’s about max MPG.
______________________________________________________
(Quote)
August 17th, 2009 at 7:31 am
“The message on charge sustaining mode is we’ve got a good beat on it, its the four or five things that have to be balanced together and the team needs time to work.”
___________
This response shocks me a bit, this late in the game. These “four or five things” have always been the real barriers to weather series EREV would work or would not work. The charge sustaining mode was the primary thing in question about the volt’s viability, right from the start.
This is one of the first times we’ve seen a GM rep really stay on the subject for any length of time and all he can do is raise the same questions that everyone’s been asking since this project’s inception.
These are the questions that you’d want answered in computer simulation, on the test stand, and in a mule before you ever green light any production.
(especially when you’re out of money already)
(Quote)
August 17th, 2009 at 7:31 am
Why not let the driver decide? The Volt could offer two different modes of operation for the gasoline engine. The standard mode, which GM seems to be favoring, would emphasize transition smoothness and responsiveness similar to a regular car. The second mode would favor running the engine at its sweet spot as much as possible, even if that means a driving experience unfamiliar to the average driver.
(Quote)
August 17th, 2009 at 7:36 am
Ooooh how fun! A list of things that break when they should.
Number 1 explosive bolts on aircraft canopies during the ejection sequence.
That was a a pretty lazy critique of the G6 in the previous thread even if I was never very fond of Pontiacs.
You are free to love a stick (well not LOVE a stick). Just don’t pretend it’s character-building.
(Quote)
August 17th, 2009 at 7:39 am
I wasn’t pretending anything.
You are really an A$$.
I am surprised by that because you have always seemed like a good bloke.
(Quote)
August 17th, 2009 at 7:44 am
Yes that concerns me a bit. One would think the IVERs would be used to optimize production techniques and final parts. But perhaps they are taking the opportunity to tweak the software because they still can?
Definitely job one for the mules at least.
Guess we just cross our fingers and hope it turns out.
(Quote)
August 17th, 2009 at 7:45 am
“We have this benchmark we set, that we’re going to blow them away”
———————————————–
I love it! these guys are doing it right.
And Frank Weber is TOTALLY RIGHT to insist, as the article puts it, “its not quite perfect, he wants it so that no one can hear it.”
Go Frank! Make it the best in the world! That is the ONLY way to go.
GO GM
GO VOLT!
(Quote)
August 17th, 2009 at 7:51 am
I don’t agree with CARB and others that the ultimate goal for the Volt is to use the least amount of gasoline. That will only lead to the failure of the Volt program. This car must differentiate itself from all other hybrids available today. It must elevate the playing field about what makes up an acceptable American hybrid automobile. If GM was simply satisfied with the Prius “bump” drive characteristics, why wouldn’t you just buy a Prius?
I’m not saying that extreme MPG isn’t one of the goals; it is and should be, but there isn’t just a single goal. The volt is a GM product and it had better feel like one; pull like a Camaro, ride and sound like a Buick or Cadillac, and carry passengers and gear like a GMC. Nothing else will BE the game changer that they need!
Show a little patience. Let the GM folks finish the job. The Volt team has already demonstrated that they have the right stuff. In the mean time, keep saving your pennies so that, when the time comes, you can put your money where your mouth is!
(Quote)
August 17th, 2009 at 7:54 am
I agree with James, give two or three modes to the driver.
-Efficient mode – Run the engine when it makes the most sense for fuel efficiency
-Comfort Mode – Hide the engine from me so I can impress the passenger
(Quote)
August 17th, 2009 at 7:57 am
I’ve been a bit hard on you and that is the truth. My hope was that your subsequent comments would be more considered and well thought out. So I will apologize for calling you an idiot since I knew that would likely negate the educational value.
I’ve always found your other comments very insightful and interesting and was a bit shocked when you penned your judgment on the G6.
Especially when there are so many genuine quality issues with rides other than the G6.
(Quote)
August 17th, 2009 at 8:00 am
Yeah, when I go out for my walks during my lunch hour it amazes me how every Prius I see on the slow side streets (there a lots of them in this “look how green I am” neighborhood) has its gas engine running.
I have never heard one go by in electric only mode, although maybe the newest ones are better. I haven’t seen one drive by where I walk yet.
It just brings home the point that the Prius is basically a gas engine car with an electric assist. The Volt, however, will be electric drive at all times.
(Quote)
August 17th, 2009 at 8:04 am
“The regulatory guys are not going to let us do that,”
Thank goodness the boys and girls of CARB are putting demands on GM to make this thing work they way those bureaucrats think it should. We would not want GM to be free to just optimize the car as their engineers see fit.
Bigwigs on county and state boards always know better than some nitwit engineer.
(Quote)
August 17th, 2009 at 8:08 am
That’s what i was going to type. If they have the initial starting of the engine already nailed, so that its inperceptable to the driver, I think that would be mission accomplished. The engine starting for the first time would be unexpected by the operator, unless they are constantly monitoring their battery to hit 30%. Now on the other hand, if i mash the gas pedal, i’m going to expect to hear some noise. So don’t worry about trying to feather the RPM’s up on the engine. Just let it go. KISS.
(Quote)
August 17th, 2009 at 8:08 am
Much of this has been done before with cruise control. Cruise control requires input from the environment – uphill / downhill / headwind / tailwind – and so forth.
At least from the interview, it is clear that GM is asking the right questions. Fortunately, GM is also making 80+ production accurate vehicles to use as test platforms, so there will be no shortage of vehicles needed to sort all this out.
As an aside, Lyle, if you wrote this article, would you mind attaching your name to it? I am no longer certain whether it is you are statik writing these articles.
(Quote)
August 17th, 2009 at 8:12 am
Yes if gas consumption were the over arching concern it would be pulsing like a squid looking for the earliest opportunity to shut down.
My assumption though was that in charge sustaining mode the ICE was splitting the power between the generator/battery pack and sending current directly to the wheel motors. Is this not the case?
(Quote)
August 17th, 2009 at 8:13 am
I think the Mules and any simulations, including the accelerated testing on the batteries, was to prove function. What Tony is talking about now, is perfecting the driving experiece. The function of the EREV technology, i believe has already been proven.
(Quote)
August 17th, 2009 at 8:17 am
Remeber you also have different modes for the regenerative braking. Sometimes too many choices for controls is a bad thing. But maybe this would work. People could play w/the combinations of how they want their ICE to run and how they want their regenerative brakes to work. As long as its simple enough so that most people understand it.
(Quote)
August 17th, 2009 at 8:23 am
I hope so! I drive across I-81 in PA once or twice a year and I hope the down hill portion will be EV mode and will build up extra reserve above the 30% rather than to waste it.
(Quote)
August 17th, 2009 at 8:23 am
Schmeltz and ziv
I agree that this was the best, most candid interview we’ve been treated to in a very long time. Maybe the best to date! Thanks Lyle.
Ziv, you say anal retentive like it’s a bad thing (g). Almost all engineers are in that mode because they HAVE to be, to be great engineers!. It’s not OK if the bridge meets in the middle and is “almost perfect”. Things have to be “just right” – and that’s a GOOD thing. It also ratchets up the internal pressure (like there wasn’t enough external pressure), which makes the process even tougher.
These people are trying to please about 4 different masters (not counting themseves). Keep the mileage UP. Keep the noise DOWN. Keep the customer HAPPY. Keep the critics at bay (by definition you won’t please them). On and on it goes.
This interview goes a long way to adding to my patience in waiting for a preproduction volt to be pranced about in front of the media in charge sustaining mode.
All the “solutions” floated here have one thing in common – we don’t have all the facts. “For every complex problem there is always a simple solution, which is almost inevitably wrong”
Best of luck to all the conscientious GM engineers!
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
(Quote)
August 17th, 2009 at 8:23 am
I hope and actually expect that they will do this. Of course, the EPA rating will be on the worst setting.
(Quote)
August 17th, 2009 at 8:24 am
Truce then, my friend.
(Quote)
August 17th, 2009 at 8:28 am
My hope is the tweeking process never ends and I will be receiving updates via lone star for the life of the car.
(Quote)
August 17th, 2009 at 8:32 am
I totally agree with this approach. After about two weeks the “second mode” will become familiar, and for me it won’t be objectionable. I look forward to experiencing that mode.
(Quote)
August 17th, 2009 at 8:32 am
I still want updates for the life of the car BUT, I would like to be able to select the second mode because I would willing sacrafice a bit of engine noise for better MPG and the car slipping back into EV mode for ANY ADDITIONAL miles of EV mode.
(Quote)
August 17th, 2009 at 8:34 am
“The charge sustaining mode was the primary thing in question about the volt’s viability, right from the start.”
This is so wrong.. there was never any doubt GM could build a genset and stick it in an electric car, this is trivially easy.
The Volt’s viability (in the long term, 1st couple of years will sell out) is the total cost and warranty issues with the battery.. its a race between mass production lowering the cost and the public losing interest.
BTW, engineers will always tweak software until the last minute.
(Quote)
August 17th, 2009 at 8:35 am
Lone Star being the bigger, bolder, and Texan version of on-star?
(Quote)
August 17th, 2009 at 8:38 am
Agreed. Moving silently but not wordlessly forward into the VoltAGE!
(Quote)
August 17th, 2009 at 8:41 am
A bit off topic but looks like the Gen 5 Fuel Cell fits in an I-4 space:
http://green.autoblog.com/2009/08/17/honey-i-shrunk-the-fuel-cell-next-gen-gm-hydrogen-stack-gets-s/#comments
(Quote)
August 17th, 2009 at 8:43 am
Great article Lyle.
It clearly shows the complexity involved in the development of a quality vehicle and why you can’t just slap some parts together and start selling it. I am sure the software algorithm will be a continuing refinement for the entire life cycle of the Volt platform. It sounds like they could put it out right now and most people would be happy with the results compared to current hybrids. That means there is little schedule risk associated with this issue. That is good news.
(Quote)
August 17th, 2009 at 8:44 am
Dang!! I should never try to think after drinking the night before!
Maybe Lone star is a place to eat. So my excuse is I was hungry, not hung over!
THATS IT, FORGET THE DRINKING PART, AND NO THE CAPTAIN WAS NOT THERE!!!
(Quote)
August 17th, 2009 at 8:51 am
I love it when people “play nice” (g).
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
(Quote)
August 17th, 2009 at 8:54 am
I agree with Gsned57 that maximum MPG should be a primary consideration and queitness as a secondary or better yet have it as an option, two different programs the customer can toggle between, IE quiet mode or MPG mode with the press of a button. Surely there is enough memory to hold both programs and or subroutines. Use quiet mode to impress your friends then MPG mode while commuting.
(Quote)
August 17th, 2009 at 9:01 am
old man,
I’m on I-80 in PA but 90 miles west of I-81. I-81 has some huge hills, most of which are missing on I-80 (E/W).
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
(Quote)
August 17th, 2009 at 9:04 am
kdawg,
If you mash the pedal from a dead stop don’t you want all the instant torque from all electric?
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
(Quote)
August 17th, 2009 at 9:05 am
I think they should make it as quiet and smooth as possible for the masses. There are always the tinkerers and hackers that are going to immediately start tweaking the software to get more MPG, which is us hardcore people that will be visiting the owners forums many times daily, neglecting our health, jobs, loved ones to eek out another mpg. =)
(Quote)
August 17th, 2009 at 9:12 am
Kdawg,
That’s my take as well. They have the piano built, it just needs to be tuned.
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
(Quote)
August 17th, 2009 at 9:14 am
(click to show comment)
August 17th, 2009 at 9:14 am
Herm,
These issues sure didn’t sound “trivial”. JMO.
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
(Quote)
August 17th, 2009 at 9:15 am
“Is the EPA sitting on a committee while you engineer the car?
This is more CARB than it is EPA. EPA is interested from the perspective that they need to understand how to label it. CARB really doesn’t want you to burn fuel if you don’t have t”
—————————————–
Since the Volt will be in short supply anyway, maybe it should be designed to be sold outside the CARB zone and without their supervision. Sounds like it would be a better car. (smile)
(Quote)
August 17th, 2009 at 9:15 am
In case none of you have done it yet… go to your Ford Dealership and test drive the 2010 Fusion Hybrid. I have had mine a month (tomorrow) and am just loving this car.. as for the trasition from ICE to EV… it is flawless..Most times you have to be watching the instrument panel to see the switch over. As for mileage … it blows the Prius and the Camry out of the water.. Lifetime average so far is down to 5.5 L / 100 KMS (51.4 MPG Canadian). and it is still going down..
I was expecting to be close to the EPA standards of 5.4 L / 100 in town and 6.1 L / 100 KM on the highway. But I have run difffernt trips of varining lenghts and can acheive super MPG numbers…
Best so far 2.1 L / 100 KM and worst was 7.9 L / 100 KM.
The car does run for a couple of minutes most mornings about a minute after ignition is on.. I think it has something to do with a “systems check” and making sure the battery is up to speed.
I am not filling up often and am acheiving well over 1100 KMs per tank (66 L).
It’s bigger than the Volt…costs well under the $40 K mark and seats 5. I still want a Volt when they get here but I will be keeping the Fusion for the Family trips..
(Quote)
August 17th, 2009 at 9:16 am
James,
I like the idea of being able to choose, but which does the EPA test for the plethora of #’s on the window sticker?
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
(Quote)
August 17th, 2009 at 9:17 am
“By the way, our motor is so much bigger than theirs, the power output of the electric motor, that effectively is the starter.”
——————
Do you think this means there is not a normal starter for the ICE?
(Quote)
August 17th, 2009 at 9:23 am
kdawg,
And when you found a favorite combination, you could press a button oin the fob to remember the combo, so two drivers could have different setting in their own fob – a little like my seat has 2 memory settings – for my (short) wife and for my (taller) self.
But again, what does the EPA use for it’s testing? An average? Shrug.
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
(Quote)
August 17th, 2009 at 9:24 am
That’s good news. I’d avoided the Fusion because, well, it seemed like false advertising. Nice to see they’ve put something interesting under the hood. (Still holding out hope for the Mr. Fusion version)
(Quote)
August 17th, 2009 at 9:24 am
GM is over designing this. Please remember KISS. Forget the idea that when driver push the accelerator down that they should hear some increase of generator like an ICE. DO NOT try to copy an ICE experience. This is an EV based vehicle and people will get us to it. Focus on smooth transitions and take advantage of the buffer energy in the battery. Maximize the MPG with smooth transitions, and only go to higher RPM after longer period of high demand. Do not have the generator always responding to the ups and downs of energy needs. It is better to have a larger battery buffer amount then to have the generator changing modes and speeds frequently.
(Quote)
August 17th, 2009 at 9:28 am
nuclearboy,
Aren’t these regulators the national EPA Guys? Or are you talking about CARBI agree that the engineers should be in the rivers seat and present the vehicle that they decide is best, but they have to be shooting for the highest mpg too. What a challenge!
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
(Quote)
August 17th, 2009 at 9:38 am
I suggest… “The Art of Electronics” … good book.
(Quote)
August 17th, 2009 at 9:39 am
They would test the standard mode, which would be the worst of the two. Nobody is going to argue with a second option that gives them better mileage than can be advertised.
(Quote)
August 17th, 2009 at 9:41 am
Back from Vacation…
While I don’t disagree with you about multiple modes it still means the Volt team needs to finish their tuning of the ‘quiet mode’.
If the Volt drives ‘weird’ Aunt Molly isn’t going to like the car.
THAT would be a disaster for a car destined for the mass market.
(Quote)
August 17th, 2009 at 9:44 am
“trivially easy” — now there’s a description that’s so wrong I don’t even know where to start typing. (I’ve got a feeling weber and crew would take my side on this one)
(Quote)
August 17th, 2009 at 9:46 am
Agreed.
(Quote)
August 17th, 2009 at 9:55 am
I would like to add a “vote” for a driver selectable mileage or comfort mode. This would be similar in operation to the regenerative brake modes previously revealed by Lyle in his April ‘09 mule test drive:
“The braking had a customary feel. Regenerative braking was of course in effect, and every downhill grade and coast charged the pack. GM had cleverly built in two driving configuration options called D and L. Both gave the same acceleration, but when you step off the accelerator you get strong regenerative drag if in L and coast in D, the former being best for city driving. As Greg said this could allow you to drive with one foot.”
(Quote)
August 17th, 2009 at 9:58 am
I’m guessing it will take about two weeks for someone to hack the Volt software. Since all of this, the duration of EV, the SOC level, generator kick in, RPM’s and duration is controlled by software the adventurous Volt owner who doesn’t care about voiding their warranty will be able to modify and tweak their Volt however they want. Personally I would be interested in expanding the window of ‘usable’ battery from 8kwh to 10 or 12 kwh. Of course tinkering around with it could end in disaster but for the tech savvy the possibilities are all there.
(Quote)
August 17th, 2009 at 10:07 am
Same here. Bugs will be found and hopefully, dealt with correctly and quickly. Just don’t let Microsoft anywhere near the project.
(Quote)
August 17th, 2009 at 10:09 am
I am not sure who exaclty is interfering. I was just responding the to article where the guy said that they could not run the gen set in a specific way because “The regulatory guys are not going to let us do that,” (referring to CARB).
I have always thought that it might make sense to run the Generator at some max efficiency point and charge the battery up a little and then shut down when you reached some magical level (say 35%). This way, if the engine and generator are running, they will run at optimal efficiency. Running at optimal efficiency on the engine would seem like a good idea even if you are charging the battery a little.. This overcharging of the battery past 30% seems to be what they don’t want.
My concern is that low level bureaucrats on some panel or board are putting obstacles in the way of GM exploring various ICE/GEN algoritm concepts for the car.
If the approach they are blocking is no good for VOLT, GM would figure this out and the CARB nitwits should have stayed out of the process and let GM get the job done.
If the approach they are blocking is more efficient for VOLT, the CARB nitwits should have stayed out of the process and let GM get the job done.
Either way, I see CARB intervention as a drag on productivity. Interfacing with the Govt is a waste of resources for a company…. Unless maybe you are a company like GM and the Govt has just bailed you out.
(Quote)
August 17th, 2009 at 10:13 am
I don’t have any real problem with the term, it simply gives reference to when the switch occurs.
Using “Customer” DOES make sense since the drivers habits and patterns determine when transition occurs.
I have used the term “depletion point” in the past and am comfortable with that. All it means is the point in time (and charge) where the battery charge finishes depleting and the Volt starts sustaining said charge level.
(Quote)
August 17th, 2009 at 10:15 am
My (limited) experience confirms what you’re saying. If you’re not accelerating it’s hard to know when the motor has come on. It’s an almost seamless transition.
(Quote)
August 17th, 2009 at 10:15 am
I just got something in mind:
When generator kicks in, it will be aimed to keep the battery SOC around 30% (which is the initial full customer depletion point). But we all know there will be a delay between instance power needed for the driver (pushing down accelerator pedal straight) and the power that will be supplied in response. It’s clear that the instant power will be supplied from the battery, and generator will slightly increase power generation in order to bring SOC back to 30% in a short (and smooth) delay. The same occurs with regen-braking, effecting the generator will simply go in a lower power state.
If this mechanism sounds logical, the battery, at 30% SOC (user depletion) will experience frequent “yo-yo” charge/discharge rate. Will this have some negative effect on it? (battery lifetime, power)
(Quote)
August 17th, 2009 at 10:16 am
Yes i would, plus rev the ICE if needed. Dont worry about noise when i mash the peddle. I’d be more concerned/upset about a lag in the engine response. If i step on the gas peddle and 3 seconds later the enginer revs up, that would bother me more than instantaneoulsy reving it.
(Quote)
August 17th, 2009 at 10:16 am
Yes, it was confirmed in a chat that the generator acts as the starter, there is no standard 12v starter.
(Quote)
August 17th, 2009 at 10:20 am
Volt Bugs will abound. The question is how quickly can GM fix them. We don’t need the infamous Microsoft Patch Tuesday Crapola.
(Quote)
August 17th, 2009 at 10:21 am
James,
GM would argue with it, if it’s not the lowest #!
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
(Quote)
August 17th, 2009 at 10:22 am
Agree 100 Percent, this is so important it bears repeating.
DON’T LET MICROSOFT ANYWHERE NEAR THE VOLT !.
(Quote)
August 17th, 2009 at 10:24 am
It’s interesting that so many fh owners are beating EPA numbers. I attribute this largely to the engauging Eco display?
(Quote)
August 17th, 2009 at 10:25 am
Your last paragraph said it all very correctly. The Prius is not an electric car. It just has an electric assist motor. But, over all the Prius is a great car accomplishing very well what Toyota designed it to do.
(Quote)
August 17th, 2009 at 10:25 am
nuclearboy,
Well put. Uncontested.
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
(Quote)
August 17th, 2009 at 10:26 am
That’s what i thought. There’s no 12V starter. Wasnt this discussed in detail recently?
(Quote)
August 17th, 2009 at 10:27 am
I guess I was thinking that the all electric torque has been described as 100% instantly, that the engine would just slow it down! (g).
JMO,
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
(Quote)
August 17th, 2009 at 10:28 am
A larger buffer zone woud be preferable, but puts more strain on the battery. as long as the buffer is large enough to power a decent overtake at motorway speeds(~38kw for a minute/90 seconds) before you throttle back to 70 (~26kw) then it’ll be fine. if you ran the genset at 27kw output for the whole time while doing 70, you’d build enough buffer in the battery to do this, without being obvious to the driver.
I’m just hopeful that it’s easy to hack the 100mph limit, we now know the battery can handle the full 112kw load of the motor, so with the 53kw genset assisting you could go for 43 miles at a constant 120 before the battery was empty. you could even go 21 miles at 145! maybe the Ampera will have the option of their 1.9cdti diesel lump, and an uprated genset, for a higher sustained top speed….
(Quote)
August 17th, 2009 at 10:29 am
Keep in mind that there is still more than a year before the first cars are released. There is still plenty of time for this type of fine tuning. (And if this is perceived as a big issue then from an engineering standpoint the development team is in very good shape). As for the timing of the test drives, a roll out has a certain pace to it. You want to space the PR and then accelerate it towards the roll out date, so there doesn’t seem to be any advantage to having the media test drive the cars now rather than five months from now.
If they didn’t have the time then we’d have a different situation. The reality is that the more time used in development the better the product, it’s just usually that you make the big strides early on and it takes more and more time for smaller benefits. But it is an important component of the operation so I’d encourage them to keep at it.
As for the 230 mpg number being seized on, that’s to be expected. What’s funny is that you don’t see the same attack on Nissan’s much larger number which AFAIK is far less defensible. Basically there is a negative perception of GM in some quarters and this gets expressed from time to time. But it does have a good side. Given that the Volt is really something of a “halo” vehicle, without a need to dispel some negative perceptions — perceptions which “pissed off” Bob Lutz and probably a lot of other people at GM as well — I’m not sure GM would seen the need to bring the Volt to market.
(Quote)
August 17th, 2009 at 10:29 am
For best code I would suggest they Open Source it. All the experts now agree that the OSS model results in the safest and most efficient software in the industry.
BTW, what happens in closed source systems (ala Microsoft) is that poorly written code modules tend to be completely re-written many times from the ground-up because of lack of peer review and following best practices. A good example would be MS TCP/IP stack which has been totally rewritten at least five times because it has been a poster for how-not-to-write-c-code !
(Quote)
August 17th, 2009 at 10:31 am
I ‘think’ what Herm means that it’s easy to add a range extender to an electric car, it happens all the time with people sticking a generator on a utility trailer and dragging it behind their home built electric.
I bet many people on this board could do that… I could.
What is HARD and why the Volt is taking so long is getting it to work as a system, reliably, smoothy, and truly efficently.
(Quote)
August 17th, 2009 at 10:34 am
OK, found the posting. It was from Cab Driver
———————-
Cab Driver Reply:
August 14th, 2009 at 7:12 am
By the way, did you see my thread from a couple days ago ( http://gm-volt.com/forum/showthread.php?t=3218 ) reporting that when I asked Frank Weber if the 12 volt battery could start the ICE he said no, since there’s no 12 volt starter motor?
(Quote)
August 17th, 2009 at 10:35 am
Cool information. a fuel cell powered genIII volt..suh…weet.
Thanks for the link
(Quote)
August 17th, 2009 at 10:36 am
Remember the Volt is designed to be a World Car, sold in many other countries. Most likely the majority of Volt sales will be outside the U.S. once production cranks up in Europe and China. The Volt will remain a niche product in America for the foreseeable future. So it has to meet the strict EU standards on emissions, while Chinese version will have much less emission components.
(Quote)
August 17th, 2009 at 10:39 am
Sigh…
Just when I thought I had found a forum where people didn’t feel the need to bash Microsoft (While turning a blind eye to Apple) at every turn…
Oh No! Spaceballs… There goes the planet…
(Quote)
August 17th, 2009 at 10:39 am
Super interview Lyle. Congrats on a very nice exclusive.
I will say that Tony Posawatz (and Greg Ceisel) are great interviews. The passion and dedication show through — though they are very down to earth — and they are very technically knowledgeable so they give out great information. (We don’t see much of Jon Bereisa and that’s unfortunate).
(Quote)
August 17th, 2009 at 10:41 am
Muddyrover,
Welcome back!
I think by the time Aunt Molly can get her HANDS on a Volt, it will have been polished to the point were she won’t notice the different modes. I’m just saying that the Gen I’s will be awfully scarce and snatched up by the rich and the lunatic, er I mean fanatically intense.
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
(Quote)
August 17th, 2009 at 10:41 am
What we really need to know is, what is the MPG in generator mode? The 230 number is fine for publicity, but what is the real MPG of the Volt?
(Quote)
August 17th, 2009 at 10:42 am
I hope there will be some “intelligence” in the software. It has to recognize different traffic situations. It would be awful, if the ICE turned on and off every half a minute in an everyday stop-and-go / jam situation.
(Quote)
August 17th, 2009 at 10:42 am
Also here:
Live Chat with Frank Weber, 10 August 2009
5:47
[Comment From CaptJackSparrow]
no 12volt starter motor? Then what turns over the ICE to start it?
5:48
Frank Weber: The generator within the electric drive unit, which is directly coupled to the engine.
(Quote)
August 17th, 2009 at 10:46 am
This is going to be a selling point. Not just the ICE integration but the perfection of the car. At 32.5K I want a car that is perfect in every possible way. Word of mouth is very powerful. If word gets out that yes the car is expensive, but look at what a great perfect car you get, then GM will have a winner. They really can’t push that pricetag up. They are on the line now. So they must make up for that with extreme quality. I think they will surpass everyone but Chevy haters expectations.
(Quote)
August 17th, 2009 at 10:50 am
Johann,
i agree with you about “as quiet and smooth as possible” as this will lessen any stress in starting and stopping. I trust GM to do this part of the software correctly. The pre-production vehicles in consumer hands will be monitored and the data used to determine the proper settings, at the same time letting the public see and ask questions of these lucky ones driving these vehicles.
As far as people messing with the software to tweak out another mpg, this would invalidate the car warranty, especially the battery warranty. This is not something that you want to mess with. Let Toyota and the others mess with it.
(Quote)
August 17th, 2009 at 10:52 am
Re Post #5 Fellow engineer #5 makes sense. The driving situations Lyle envisions gots to be routine stuff for GM. That said, for openers priority must be given to balancing hill climbing. Even a 3% grade doubles (x2) (or more depending on load) the power demand. A 5% grade, such as going over the Sierras right here in Northern Cal. could quintuple (x5) power demand. In short, hill climbing wipes out the battery. Which raises a question: When enabled can Volt’s ER hold battery drain to x1 load? The corollary question: What’s Volt’s ER potential? The answer to this yields comparative mph. How far (at x mph at y time) + battery range = total range. Imagine a fuel tank size giving 1000 miles range.
(Quote)
August 17th, 2009 at 10:52 am
It was my impression from previous comments from GM that there would possibly be an “Eco” mode and a power mode. Some of the buttons we saw on the original pictures of the console seemed to imply this also although those buttons were never described by a GM official. But having two modes does make sense to most people.
(Quote)
August 17th, 2009 at 10:54 am
That is a useless question to 80% of the driving public.. similar to asking how many 4×8 plywood sheets it can carry.. the answer would be interesting but only useful in a handful of cases..
If you USUALLY drive more than 50 miles a day, please dont get a Volt.
GM should offer the genset as an option on the Volt.. that MAY finally make people understand that it is an electric car.
(Quote)
August 17th, 2009 at 10:56 am
I predict that the generator mode will evolve after a significant number units get into the hands of customers. Opinions will vary greatly due to different wants and needs. While the software algorithm should the best…some things should be left until customer feedback is possible.
(Quote)
August 17th, 2009 at 10:58 am
The devil is in the software details.
I remember about a year ago some self proclaimed software engineer posting how easy the software would be. No challenge at all. What a tool.
A positive thing is that the software can be updated after the car hits the road. Just go to your local GM dealer and get the latest software update. The bad thing is that things could get unpredictable. Let’s hope for bulletproof software.
(Quote)
August 17th, 2009 at 11:01 am
As I already predicted, this 50 mpg in normal highway driving will not be achievable (due to efficiency issues). Soon we will see.
(Quote)
August 17th, 2009 at 11:08 am
For the people who post here, I am sure that the VOLT, like the new 2010 Camaro, will convince the trolls that GM finally gets it and is working on the best built Chevys ever made.
That being said, I wish that process didn’t involve so much ‘overkill’. But I guess perfection comes at a price.
Why does the ICE Gen need to be “imperceptable”? I’m sure VOLT owners aren’t stupid. I’m sure there will be a SOC guage on the dash right next to the Gen Fuel Level guage. I would bet that those huge LED screens are chock full of colorful displays that will show exactly when you’re gonna run out of pure electric power, and when the gas engine is on, and at what power output level.
Personally, I think it would be cool if the display said, “generator ignition in three… two… one…” when it’s about to start up.
I’ve driven and sold several Tahoe Hybrids this year, great truck but expensive, and the “shudder” when the ICE starts and stops at a light or in the parking lot is NOT objectionable. It is barely noticable. I have to tell many customers on test drives that it has even happened. And even if I did not, the ‘oil pressure’ guage tells them it is on.
The same thing can be done for VOLT. All of this ‘extra development’ to make something as simple as engine start unnoticed is just another reason this car will be $40k. And in the same breath, another reason people should compare it to Lexus or Mercedes rather than a buzzy little Prius.
(Quote)
August 17th, 2009 at 11:08 am
Truth!
However, the media is set to pounce.
The Volt HAS to be right or it will get shredded by short sighted opportunists. Headlines sell papers and get web hits not facts. I think this is why they are playing the extended range experience close to the vest. A report of a ’slight’ unpleasantry would result in a flurry of “The Volt Sucks” stories here and elsewhere.
It’s DEFINATELY “Danger Will Robinson!”
Frank and team have their work cut out to avoid the bad headlines.
This is a difficult situation where a Gen 1 product (The Volt) really has to be close to perfect to just get a passing grade.
(Quote)
August 17th, 2009 at 11:08 am
a 2-3% oscillation around the 30% charge point of the battery wont hurt anything. Note that even at the 30% point the battery still contains 4.8kwh of juice, lots more than a Prius battery.
(Quote)
August 17th, 2009 at 11:11 am
>> As an aside, Lyle, if you wrote this article, would you mind
>> attaching your name to it?
Second that. Please +1 my post if you agree.
(Quote)
August 17th, 2009 at 11:14 am
I love the idea of the Volt with a generator to recharge the battery when it gets low. I would plan to use this car for everything including long trips.
One question that puzzles me is why did Chevy not put a motor in each wheel ( like the design from Siemens ). That design would do away with the weight of a drive train, steering gear etc and would make the car a perfect 4 wheel drive for superb control in all climates. The car would be a real drive by wire future car. I would think the price might be a little less.
DOES anyone have insight if this idea was considered and if so why was it not used. ie what are the flaws. Thanks in advance for replies.
(Quote)
August 17th, 2009 at 11:15 am
and what about the poor sob that buys this Volt used?.. yeah the previous owner restored the original code but the damage has been done. I sure hope GM uses big holographic tamper-proof stickers on all the data ports.
(Quote)
August 17th, 2009 at 11:16 am
(click to show comment)
August 17th, 2009 at 11:16 am
Brings a ‘lil tear to your eye, don’t it? *sniff*
Wistfulness aside, we have bigger fish to fry, don’t we? Onward and upward!
(Quote)
August 17th, 2009 at 11:16 am
The CARB involvement in this is very disturbing. Could it be that we will wind up with a less than optimal product because some idiot bureaucrat at CARB had control over this. CARB had better wake up and remember that if this product doesn’t sell then they are back to gas guzzling engines and even comparatively inefficient hybrids.
(Quote)
August 17th, 2009 at 11:17 am
Ya, and have the freaking thing reboot when I’m not looking
or in this case, driving.
(Quote)
August 17th, 2009 at 11:18 am
They seem to have done OK with Ford’s Sync system. *dons flame-resistant suit*
(Quote)
August 17th, 2009 at 11:19 am
I chuckle at “customer depletion point” also.
That term best describes the dealers lot about 4:00 pm on a Monday when the game is about to start.
(Quote)
August 17th, 2009 at 11:20 am
Muddyrover,
Wow you are far too (uncomfortably) close to reality, so I’ll run away now (with Will Robinson). Seriously, I fear that you are right and that the Volt will be micro-analyzed right out of the chute. Then again, I guess that’s what he was talking about in the interview. SIGH – I really hate this reality stuff. It’s much more pleasant in my world. (g)
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
(Quote)
August 17th, 2009 at 11:22 am
I think the source code & algorithms are probaby 50% of the propriotory Voltec technology. I dont see GM sharing this w/anyone. I know of lots of problems w/PC software, but have not run across too many in a car’s computer. Maybe Dan Petit can chime in.
(Quote)
August 17th, 2009 at 11:23 am
texas.. I agree with 95% of your comments, but not this one.
Here is why:
Cruze has a 1.4L ICE @ 39 mpg
The Cruze will not have a 400 lb battery like the Volt. But, it will have more transmission weight and a bigger fuel tank. The Cruze will use the standard method of burning gas to move pistons which rotate gears which rotate rubber wheels. The Cruze will require about 3000 rpm to achieve 70mph.
The Volt has a 1.4L ICE @ 56 mpg
The Volt ICE rotates a generator. Which, we both agree, is less of a load than the old way of firing pistons then gears then rubber wheels. The Volt ICE will send generated electricity to an electric motor. It will not race to 5000 rpm on hills (smell the coolant overflow?). The Volt ICE should easily average 2800 rpm. True, we won’t know until we own a Volt.
50 mpg is a certainty. With 56 being a very solid high end guesstimate.
=D~
(Quote)
August 17th, 2009 at 11:23 am
Perhaps I missed something, but this answer seems exactly the same as offered months ago. As Statik would translate, “we ah are not going to tell you.” Something that could be defined to the engineering/management decision point in a matter of weeks, using simulation plus IVER’s for validation, is being characterized as a year long project. My lollapalooza meter is pegged.
(Quote)
August 17th, 2009 at 11:23 am
Lone Star used to be a good beer. First one for me was that.
(Quote)
August 17th, 2009 at 11:24 am
Mike-O
ABSOLUTELY! Onward and upward….. To infinity and BEYOND!
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
(Quote)
August 17th, 2009 at 11:24 am
i’m sure there would a deadband in there.
(Quote)
August 17th, 2009 at 11:25 am
I think GM has thought of that. If not with such a minor detail, GM is in deeep trouble.
(Quote)
August 17th, 2009 at 11:26 am
If I remember correctly, the answer is no.
The ICE does not charge the battery.
At least, that is how I understand it.
(Quote)
August 17th, 2009 at 11:27 am
RE: Gsned57 “I don’t think they should kill themselves to make it “SOUND” like an EV all the time.”
From my perspective, it seems like they’re killing themselves to make sure it sounds like a gasoline-driven car. What with comments about raising the engine RPM to match how hard you’re pushing the “gas” pedal.
As a friend once pointed out about meat-simulating vegetarian products: “Why put so much effort into recreating what you’ve voluntarily avoided? Do monks have sex dolls?”
(Quote)
August 17th, 2009 at 11:27 am
There was an article in R&T or C&D a while back about a Mini Cooper that had hub motors placed in all 4 wheels. Incredible power and performance, But it would not pass federal safety guidelines beacause there was no emergency or backup braking system. Nowhere to put it.
(Quote)
August 17th, 2009 at 11:27 am
I’m sorry, but I totally disagree with that. This car should be able to make -40Miles AND +40Miles daily commuters happy. Otherwise, there is no reason to put so many effort in designing and fine tuning the genset the way GM does. If you say that this car is basically for -40Miles commuters, simply put a V6 engine as genset and don’t bother more. We will still get our “triple digit mpg” (which is a true false statement, imo).
I’m unfortunately not a 40Miles commuter. I get to work using public transportation. I do use my car on week-ends for about a 150 miles away trip.
On a additional note, the E-REV concept itself is all about remove the link between an ICE and the wheels. You create a whole new space for ICE power efficiency improvements. This is what I’m mostly interested, and this is the second key information we are missing at the moment.
(Quote)
August 17th, 2009 at 11:28 am
This interview goes a long way to adding to my patience in waiting for a preproduction volt to be pranced about in front of the media in charge sustaining mode.
All the “solutions” floated here have one thing in common – we don’t have all the facts. “For every complex problem there is always a simple solution, which is almost inevitably wrong”
________________________
Thank you Tag. That is exactly what I think about when people complain GM is not being forthcoming and transparent, or everything should be done now and people should have Volts for unlimited test drives.
Personally I am not engineering, nor co-engineering, nor back seat engineering nor Tuesday morning quarterbacking the Volt engineering groups. That’s not on my resume; and I get pretty tired of people pronouncing GM should start acting like a Microsoft clone and just put their cards on the table ready or not.
Many go on to state with absolute certainty that unless GM follows their advice they’re doomed. I’m not an expert but I think when the car is released, people outside GM will drive it.
And not only that but GM will put out documentation called an owners manual, will have staff available to answer questions from the press, and will even train some of the dealers sales staff to answer questions from the public.
(Quote)
August 17th, 2009 at 11:30 am
From ShockMe: “My assumption though was that in charge sustaining mode the ICE was splitting the power between the generator/battery pack and sending current directly to the wheel motors. Is this not the case?”
Is the ICE storing energy or supplying power to the wheels? – or both?
Does anyone know this??
Thanks for the reminder if already discussed.
(Quote)
August 17th, 2009 at 11:32 am
A button can be re-purposed at any time. What the heck is a “hold” button, anyway?
(Quote)
August 17th, 2009 at 11:33 am
The law regarding braking systems is simple. The law states there must be friction type brakes on all wheels of the vehicle. If this helps.
=D~
(Quote)
August 17th, 2009 at 11:33 am
I would think (hope?) that the NAV system would be linked into the control software. In this way the car would KNOW what the road ahead has in store so it can optimise the trip efficency.
I don’t see this as being a huge inconvenience, my $100 Tom Tom remembers quite a few destinations, so it’s as easy as clicking ‘home’ and it has all the info it needs.
I’m buying the loaded one, I guess the entry model would have to do without that sort of integration.
(Quote)
August 17th, 2009 at 11:35 am
Superb! Now off to the lab, where I’ll build myself a completely leakproof, crashproof, lunchbox-sized, 50,000 PSI H2 tank.
(Quote)
August 17th, 2009 at 11:35 am
That’s a really good idea, I like it.
And I’m sure if we go through about 3 million lines of now discarded code, we could determine the point where GM engineers liked it too.
(Quote)
August 17th, 2009 at 11:36 am
Amendment: I did see that ABG article and the size/volume reduction between gen4 and gen5 is astounding. So is the reduction in platinum use, apparently with more improvement to come in that department.
I surely didn’t mean to belittle the achievement… It’s just that I get depressed thinking about H2 storage and supply/transport issues.
(Quote)
August 17th, 2009 at 11:38 am
It is trivial.. here let me give you the secret formula they could use.. for free.
1. Driver is happily motoring about, he has gone about 60 miles and at that time the computer determines that the battery has reached the 30% point (actually this can be hard to do).. it starts the genset slowly, over 15 secs it ramps up to the desired power output point, again determined from data the computer has been collecting for the past few minutes.. the computer tries to match the output to the AVERAGE power demands of the driver. This can be achieved by varying the ICE throttle, timing or field excitation of the generator.. this will be computer controlled to meet pollution and MPG requirements. The driver suddenly steps on the gas when he reaches a zone with no speed limits.. after a set time the computer increases power output to match the new demands.. but that reaction time may be slow since it has such a huge buffer battery and quick reaction is not needed.
2. the driver severely steps on the brakes or comes to stop.. the computer immediately slows down the engine to idle or maybe even stops it.. but if the computer detects the radio is playing at a sufficient volume it may elect to keep the engine running, but only for a limited time. Go back to step one.. change the program if the driver selected a different mode and so on.
(Quote)
August 17th, 2009 at 11:41 am
I can easily understand why GM is not giving much details about the ICE sustaining mode.Let GM get it perfected first and keep the competition guessing. Then, next year, show the world. By that time, it’ll be too late for the competition to copy from it.
(Quote)
August 17th, 2009 at 11:41 am
Right you are Mike.
(Quote)
August 17th, 2009 at 11:46 am
The genset can charge/return the battery to the depletion point if it goes below under severe usage.
However under normal steady state operation the genset power would go directly to the drive motor. This could be common on a flat freeway but I bet the battery will be ‘buffering’ driving variations (start/stop) the rest of the time.
(Quote)
August 17th, 2009 at 11:47 am
They are many drawbacks with having the motor in each wheel. Weight is one. Having all that extra weight going up and down for each bump would take a toll. Another, is the harsh environment of dirt, water,ETC.
(Quote)
August 17th, 2009 at 11:49 am
>> Imagine a fuel tank size giving 1000 miles range.
Now imagine a Beowulf Cluster of these!
D’oh!!… sorry, thought I was on Slashdot for a second, there.
(Quote)
August 17th, 2009 at 11:49 am
“If you USUALLY drive more than 50 miles a day, please dont get a Volt.”
This argument is totally circular. If you drive UNDER 50 miles, why would you consider the Volt, and not a BEV. It seems ardent Volt supports say they will never use the extended range, so why not just get a BEV with a 100 mile range?
On the other hand, I drive over 50 miles a day, therefore am the perfect candidate for a Volt. I will utilize the range extender, which is the main selling point of the Volt.
Therefore I want to know the MPG!
(Quote)
August 17th, 2009 at 11:50 am
” I think GM is being tone deaf on two points, the generator mode is not going to be used that often by most drivers, and only the anal retentives are going to fault them for having an IVer that allows you to hear the generator, as long as it is programmed to follow driving cues, i.e. the generator slows at times the car is stopped. ”
I think you are describing the reviewers that will comb the car for nits to put in their articles… also, the people that will test drive these cars prior to buying them will be attentive to anything unusual.. and any sound will be unusual in a whisper quiet Volt.. even normal tire noise may be too much for some.
(Quote)
August 17th, 2009 at 11:53 am
Also, increased unsprung weight is the enemy of good suspension & handling. And I gotta believe four small motors are less efficient than one or two bigger ones. Experts, chime in please!
(Quote)
August 17th, 2009 at 11:53 am
Pretty sure they don’t. Excellent point
(Quote)
August 17th, 2009 at 11:54 am
You do make me laugh No Name…
At least you should be out of the rain under the bridge…
(Quote)
August 17th, 2009 at 11:54 am
I’m sure the “tweaking “or refinement and advancement of the propulsion system will continue as long as EREV exists. There will be plenty of aha moments, breakthroughs, man that’s obvious why didn’t any one else think of that type of ideas. The ICE has been developed for over a hundred years and people are still trying new ideas.
Henry Ford probably had an idea for HCCI and never built it because he could never prioritize the two or three hours he guessed it would take to design it. It’s a fact though that Edison never made a long range electric car, even though for most of his life he thought he only needed “a couple more months” to build a better battery that would make it possible!
(Side side note, Tesla claimed that despite despite Edison’s capacity for invention he was ignorant of science and engineering, so maybe Edison just didn’t have the perspective to know the job was impossible, again. Will we know were the next breakthrough comes from?)
The one sure thing is the development will continue, the Voltec system is not a perfected piece suitable for framing in museums, yet.
(Quote)
August 17th, 2009 at 11:58 am
You bring up an interesting question. As a prospective customer, how do you experience Charge Sustaining mode? Most test drives aren’t very long and my guess is that the car will be fully charged when you go out because what you really want to experience is the EV drive.
(Quote)
August 17th, 2009 at 11:58 am
Answered my own question… The answer is both…
from an earlier post: http://gm-volt.com/2008/09/27/how-charging-of-the-battery-works-in-the-chevy-volt/
Thanks All.
(Quote)
August 17th, 2009 at 12:01 pm
This to me is somewhat puzzling. The mass would be similar whether in the wheel or suspended above it. Would not having some of that weight directly on the road surface put less pressure on the suspension given that it is not….suspended?
I should think that damage to the motors would be the primary concern. The potential for all wheel steering would have been cool though.
(Quote)
August 17th, 2009 at 12:10 pm
I think I’ll go with Texas on this one. GM has said the computer model predicts 50 MPG. The models are always overly optimistic so you’d normally expect a bit lower MPG. Also, my guess would be that GM will sacrifice some efficiency for what it deems a better user interaction (though I think we could adapt better than they seem to think). So my wild guess is 45 MPG.
But does it really matter? Seems to me that opportunistic charging will be much more important. For example, take Rashiid’s hundred mile commute, which is quite a long one. For him charging at work will be far better than getting 55 MPG rather than 45 MPG. Not only is the EV mode vastly more cost efficient — and more fun! — getting 45 MPG rather than 55 MPG doesn’t involve all that much of a fuel penalty. Over 5000 miles we’re only talking about 20 gallons of gas.
(Quote)
August 17th, 2009 at 12:11 pm
Yes I agree 100%.
I think the only things that needs to be done is a way to left the driver know why thier car is acting “strange”.
I favour an “Electric Boost” Bar right next to the Speedometer. When that bar is “low”, the engine will need to run at say a stop light. But at the stop light you can clearly see -why- its running.
(Quote)
August 17th, 2009 at 12:12 pm
So when it’s really cold and the genset kiscks on the very first thing. Is it still “CD” or “CS”? Hmmm…….
(Quote)
August 17th, 2009 at 12:15 pm
Good one! I’m not a monk so I can’t answer the sex doll question!!!
But your point is well taken. Remember all those (horrible) user interfaces for the early software programs that tried to make the program look like an office with desks and filing cabinets? Ugh! People are very adaptable IF they want to adapt. A slightly different experience seems like a small price to pay for greater efficiency.
In this regard, the lack of a true “freewheeling” mode seems like another pox visited on us by the perceived need to make driving the Volt similar to a conventional car.
(Quote)
August 17th, 2009 at 12:17 pm
I don’t think we have anything to worry about in the sense of “Noticing” the genset kicks on.
IMHO, who cares. It’s on it’s on, it’s off it’s off.
If the beers cold, do you complain?
(Quote)
August 17th, 2009 at 12:17 pm
I drove the 2010 last week. Engine start/stop is practically undetectable. It’s very quiet even under full acceleration.
(Quote)
August 17th, 2009 at 12:22 pm
ziv: “I think Weber is letting perfect be the enemy of very good.”
Well, he knows what he’s doing. This must be important or the effects are more severe than they’re letting on.
What concerns me a little, is how they’re going about the “tuning.”
If they’re adjusting parameters or modifying easily debugged subroutines (or objects, as we’re in the 21st century, now), then the overall quality of the code at launch should be as good as can be expected and testing today is almost perfectly relevant to what will be in Customer Vehicle 1.
However, if they’re rewriting entire collections of objects, changing calling interfaces and overall flow of engine management code, then the code for Customer Vehicle 1 will be pretty fresh and bugs are much more likely.
(Quote)
August 17th, 2009 at 12:23 pm
IMHO, hearing/feeling the car is how many troubleshoot a car. If I never notice the genset kicks on/off then I’ll never know if it supposed to under any conditions.
(Quote)
August 17th, 2009 at 12:31 pm
I bet they are playing with electronic compression release valves and big ignition timing swings.
(Quote)
August 17th, 2009 at 12:38 pm
What about Linux which is open source? Homany differen’t variations are there? What kernel is being used? What GUI is used? How does one get a specific kernel to run an rpm file for install? Why does one command work on one version but not the other partys?
Perfect example of no control or consistency or STANDARDIZATION.
(Quote)
August 17th, 2009 at 1:00 pm
Just curious, what’s an “inefficient hybrids.” and who makes it/them?
(Quote)
August 17th, 2009 at 1:02 pm
…and warm with his sheep!
(Quote)
August 17th, 2009 at 1:07 pm
You must have missed his name at the very bottom, after the related links list. Statik’s name was on his post, too.
(Quote)
August 17th, 2009 at 1:07 pm
Citing to Beowulf is cryptic enough. Beowulf Cluster is more so. Never been on slashdot. So few understand and even fewer get it. My ‘in-cheek’ comment, notwithstanding GM’s 230 claims, intend to spur thinking. With your conclusive ‘D’oh!!’ — that was missed. Happily I explain.
Take a level trial speed – 40 mph. Battery propulsion first – 40 miles or 1 hour. With ER enabled and no intermittent (or overnight) charge — how long will the EV run on ER? That will determine total range. If 1 gal. goes 40 miles – 20 gal. + the battery totals 1040 miles. Now how close are we to that. Pretty close. For example, the Smart Car .7 L turbo gas (premium) at 45 kW is a very good reference. Let’s say we double our assumptions (and thereby assume 90 kW) – that’s a 40 gal. tank. And you know what – I have a 31 gal tank (GMC 1987 – 311,000 original miles) and its compact enough I can hold it in my hands.
(Quote)
August 17th, 2009 at 1:12 pm
So if there is no 12V starter (thank you for the links), does that mean that the Volt cannot be jump started from another car?
(Quote)
August 17th, 2009 at 1:14 pm
Also lets say you just went up a monster hill and the engine feathered up a little to support you and you get to the top of the hill and hit a light. Should the engine keep on running to allow you to recover or do you turn off the engine because the customer expects it too because they’re stopped at a light?
—————————————————-
You should let the engine keep on running. That is the same thing that happens now if the engine idles-up because of the air conditioning, for example So long as the car does not pull against the brakes, soon you don’t even notice.
(Quote)
August 17th, 2009 at 1:15 pm
or Iced Tea
(Quote)
August 17th, 2009 at 1:23 pm
A fair and interesting question!
I don’t have a good answer there.
(Quote)
August 17th, 2009 at 1:27 pm
I like the “driver-controlled” scenario where I can choose when it comes on and at what power. Just imagine being at a stoplight and kicking on the genset at 4000 RPM !!! You could scare the beejeeezuss out of those unsuspecting blind people at the crosswalk! Or, grit your teeth and hunch your shoulders and pretend you’re going really fast while the guy next to you looks on!
(Nah. I’m just kidding. I don’t know how they’re gonna fix that.)
(Quote)
August 17th, 2009 at 1:29 pm
You just had to pull out a Back to the Future reference, didn’t you? Good work.
We’re down to the nuts and bolts – of getting butts in Volts (see what I did there?)
And yes, I intentionally posted as the tenth sub-post so that noone could reply to this. Feels strangely like an accomplishment (kinda like the old “first!” posts, but different).
(Quote)
August 17th, 2009 at 1:31 pm
Good point! I wonder if there will be a feature on the Volt that will allow you to run it in charge sustaining mode when there is still significant charge left. If so, then you could try it out during a test drive to see what the charge sustaining mode is like.
(Quote)
August 17th, 2009 at 1:32 pm
>> However, if they’re rewriting entire collections of objects, changing
>> calling interfaces and overall flow of engine management code
I doubt that’s the case. I’m sure they have internal methodologies and have established code libraries that they’re using. No reason to reinvent the wheel for R&D that’s already been done.
(Quote)
August 17th, 2009 at 1:33 pm
That is an interesting question!
I can’t help but think that the software would start the genset well before the pack got to that point and would bring the battery pack back to minimum charge.
If the pack DID get to zero charge you have bigger problems that a boost just isn’t going to fix.
I would think at that point a ride on the hook back for repairs would be in order.
(Quote)
August 17th, 2009 at 1:34 pm
jeffhre,
Thanks for the kind words.
I don’t know what’s wrong with your resume’, but mine has ALL those titles (g). Talk about multiple personalities (lol).
I’m of the sort that actually does read the manual, but until one is available, this site is the absolute next best thing.
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
(Quote)
August 17th, 2009 at 1:35 pm
I’m skeptical that is possible to code one solution for every scenario. Sounds like maybe they need a toggle setting so the driver can choose between “performance” and “luxury” modes.
In luxury mode, the ICE and electric motor transitions could be as buttery smooth and imperceptible as possible. In performance mode, the transitions could be more abrupt so as to immediately match the power needs of the driver.
(Quote)
August 17th, 2009 at 1:36 pm
Yes, I agree. Good idea – hope GM is listening.
(Quote)
August 17th, 2009 at 1:38 pm
>> I’m not a monk so I can’t answer the sex doll question!!!
I missed whatever led to you saying this… but I believe I’ll elect NOT to read backwards to find it
(Quote)
August 17th, 2009 at 1:38 pm
I agree with you but understand that until the car is truly complete they really can’t give a solid number.
I’m one of the one’s that think the MPG number is going to be very good with the genset running and am trying to be patient until the numbers are released.
(Quote)
August 17th, 2009 at 1:47 pm
Neither. It’s “BC”– Battery Conditioning. While it’s possible the battery gets topped off a bit, the real goal is spooling up heat to the water pipes running through the battery module, so I’d expect most of the electrical output to go through heating elements.
(Quote)
August 17th, 2009 at 1:50 pm
I’m afraid you misunderstand. My “Doh!” line was me, lampooning myself. No reflection on your comment. Sorry for sidetracking the conversation!
>> Never been on slashdot.
No worries friend.
Which is why you didn’t get the joke!
(Quote)
August 17th, 2009 at 1:54 pm
Lyle, I wish you had asked him if the Volt would let owners save the battery charge for later use. There are probably a good number of drivers whose commutes are something like this: Get on the freeway (which is close to their residence), drive a good number of miles, and then exit the freeway and weave their way throughout lower-speed residential streets for many more miles until they finally arrive at their destinations. I’d rather kick off the commute in genset mode and then switch over to battery mode when I got off the freeway, since lower speeds combined with regen braking would seem to favor efficient battery use more than freeway driving.
(Quote)
August 17th, 2009 at 2:01 pm
The goal of the Volt is to make electric vehicles seem mainstream. The Tesla has “cool” and “fast”, now GM needs to make average joe and friends think that electric might not be so bad after all.
(Quote)
August 17th, 2009 at 2:04 pm
I completely agree. Do you ever listen to a commercial on the radio, where at the end they take an auctioneer and speed up their voice by a factor of 10 to get through the disclaimer? (Or on TV, where half the screen is in microtype that disappears after about 2 seconds?) No doubt someone somewhere thought that this regulation would help consumers, just like CARB thinks their regulatory heavy hand will help curb fuel usage. They never think through the unintended consequences of such regulations, including the loopholes that people can come up with to circumvent said regulations.
One of Einstein’s quotes that I really like is this one: “Everything should be made as simple as possible, but not simpler.” Regulations are a necessary evil, but it is all too easy to overdo it.
(Quote)
August 17th, 2009 at 2:11 pm
Why is it they released the “230″ MPG number, but not the generator mode MPG number? If they figured out all the calculations to get that EPA estimate, surely they have the genset MPG??
(Quote)
August 17th, 2009 at 2:16 pm
You just have to figure that there will be a way to tell if and when and with what the Volts system has been updated with.
(Quote)
August 17th, 2009 at 2:26 pm
I really hope they’re using unit testing with their software development!
(Quote)
August 17th, 2009 at 2:31 pm
This is a very big issue!
What we are talking about is refered to as unsprung weight.
This includes the wheel and tire (tyre for our Euro friends) brakes spindle (upright) and the control arms. (all the bits that bounce up and down with the wheels)
The short version of a complicated issue is that lighter is better for good handling and a smooth ride.
All that weight bounces around on each and every bump in the road, the less weight going up means that the wheel can go up and down without greatly shaking the cars structure. Less shake equals smoother ride and rubber that is touching the road.
Wheel motors although VERY interesting and used very successfully in heavy trucks are unsprung weight which would almost certainly ’screw up’ the driving experience in a small car.
(Quote)
August 17th, 2009 at 2:35 pm
The answer to your question about the hub wheel is in the link below.
http://green.autoblog.com/2009/08/06/greenlings-what-are-in-wheel-motors/
(Quote)
August 17th, 2009 at 2:37 pm
Lets be honest here, the buyers of the first and possibly second gen Volts are going to buy the car from an order form.
‘Test drives’ are only going to become an issue for gen 3 and later.
By then EREV won’t be all that weird.
(Quote)
August 17th, 2009 at 2:42 pm
OK, I can’t resist…
Lonestar drove a flying Winnibago with his faithful sidekick Barf.
(Spaceballs)
True movie genius!
(Quote)
August 17th, 2009 at 2:49 pm
I like this idea.
(Quote)
August 17th, 2009 at 2:55 pm
“it’s easy to add a range extender to an electric car, it happens all the time with people sticking a generator on a utility trailer and dragging it behind their home built electric.
I bet many people on this board could do that… I could.”
______________________________
OK. This is ridiculous. For as long as I’ve been posting on this forum. You guys think I’m talking about GM just having the ability to get an EREV rolling down the road???
WTF?
I’m talking about
-mpg
-power fade
- battery life
- generator efficiency losses
- cost of development
- cost of maintenance
- I could go on . . .
All these things will determine weather the car Is VIABLE. Will it stand up to the competition? Can it ever pay for its own cost of development and then make a profit?
from wikipedia: “viability in economic development indicates the ability of benefits to cover costs in development projects.”
MRR: can you provide some links to all these home grown generator trailer projects that show they had positive results with mpg and available power (i.e could these home builder projects get up and down decent inclines at highway speed? could they achieve anything north of 40 mpg while traveling 70 mph?)
//anxiously awaiting your response with links
(Quote)
August 17th, 2009 at 2:59 pm
I asked Jon Bereisa (GM’s resident rocket scientist) this question a couple weeks ago. Here is the question and his response:
[Comment From Rick Hearn]
What is the tradeoff between using a single drive motor with differential and halfshafts versus dedicated wheel motors?
Jon Bereisa:
Rick The largest difference is cost today. GM is working hard to use the wheel motors as brakes offsetting the added cost. With wheel motors you get a lot more driving performance.
====
Here is a link to the whole chat at ChevroletVoltAge:
http://chevroletvoltage.com/index.php/Blog/live-chat-with-jon-bereisa.html
(Quote)
August 17th, 2009 at 3:06 pm
“Where we’re going we don’t need roads!” would be a BTTF reference.
“To infinity and beyond!” is Buzz Lightyear in Toy Story
(Quote)
August 17th, 2009 at 3:16 pm
Please go read the EPA draft standard. Your assumption is erroneous.
(Quote)
August 17th, 2009 at 3:25 pm
Highway was rated at 100MPG, if that means anything.
(Quote)
August 17th, 2009 at 3:30 pm
There is a lot of difference in the Ford’s Sync system and the programming being done for the Volt. I have no first hand knowledge of Ford’s Sync system – just what I see advertised on TV and some off-hand comments here. I assume it is an OK system, but not essential to the operation of the vehicle itself.
(Quote)
August 17th, 2009 at 3:31 pm
That raises another question for this new third mode. What RPM range will this operate in?……..lol
(Quote)
August 17th, 2009 at 3:39 pm
Seems like a reasonable request. How to accomplish it is another question. But again, the purpose is to use as little fuel as possible. As long as you could make the entire trip under battery power, what is the worry?
(Quote)
August 17th, 2009 at 3:42 pm
Wasn’t that “overall” or combined mileage rated at 100 MPG or more?
(Quote)
August 17th, 2009 at 4:01 pm
carcus1 my friend, we are on the same side on this one, I simply didn’t state it clearly enough.
I’m not going to get into the effectiveness of a trailer generator, I ‘could’ build one that ‘could’ provide electricity to an electric car. The battery charger on the car would simply plug into the generator and it WOULD charge the battery. (There are lots of gas/diesel generators on the market, take your pick.)
That isn’t the point.
Although it would work, it likely wouldn’t work very well since the power output wouldn’t necessarily match the cars requirements. There is also the minor issue of having to monitor your own generator operation since most people will not have the expertise to automate this.
This is where the time and expertise of Frank and team come in to optimise the system for best performance and efficency.
There is ‘bodging’ something together and there is doing it right.
Technically they will both work, the Volt will do it better.
(Quote)
August 17th, 2009 at 4:07 pm
OK, Captain… I’m ready for that drink now…
(Quote)
August 17th, 2009 at 4:08 pm
As mentioned maybe a year or so ago, a natural progression for Voltec is to tell the GPS your destination, and the ‘puter could optimize ICE run modes and times e.g. Traveling north on I-81 for 250 miles; turn the genset on to the best sweet spot and charge to 80% then shut-off(instead of cycling through various rpms). Local driving – calculate energy needed to reach destination after getting down to 30%(maybe even before depending)( Incorporate elevation data in calculations) then select a run rpm and run time. If GM wasn’t government owned, would they worry about CARB stuff in a 230mpg vehicle?
Put in a red gen-on button so a user can run the gen set if and when he wants. Who owns the car?
(Quote)
August 17th, 2009 at 4:12 pm
Not necessarily. GM could run the tests for each mode. If the EPA has a methodology for factoring in both types of settings, great. If not, GM should still include the secondary mode, even if the EPA bases the ratings on the lower of the two, which would presumably be the standard mode.
The secondary mode would be a selling point for may people, even if GM couldn’t advertise specific increases to fuel economy. Word-of-mouth advertising can be more effective than official EPA estimates. Just today someone posted a comment against this post noting that he gets substantially better mileage from his Ford Fusion hybrid than the EPA rating.
(Quote)
August 17th, 2009 at 4:18 pm
Sh|t, I can’t remember if it was combined or highway now….lol.
Either way 100MPG city or highway works for me.
(Quote)
August 17th, 2009 at 4:20 pm
Long Island Iced Tea, right
(Quote)
August 17th, 2009 at 4:22 pm
I know. I was just stirring the pot a little bit ;o)
(Quote)
August 17th, 2009 at 4:22 pm
Janes,
I definitely believe (strongly) in word-of-mouth “advertising”, but if the EPA doesn’t provide it’s Seal Of Approval, I’m not sure how much weight ANY company’s claims of mileage will get. It’ll be interesting to see how the EPA ends up sorting out the actual testing next Spring.
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
(Quote)
August 17th, 2009 at 4:25 pm
LOL. LAST COMMENT = TROLL ALERT!
(Quote)
August 17th, 2009 at 4:28 pm
I believe it was “combined,” with the City portion outweighing the Highway portion.
(Quote)
August 17th, 2009 at 4:28 pm
Well, that’s true if that would be the case. What if we want to get on the freeway and head down to Longview, WA (from Seattle) to visit our good friends (and show off the quiet, smooth electric drive)? It’s a 130 mile trip to get there, and the batteries would be kaput by then. Unless we spent the night (and ran an extension cord out to where we have to park on the curb), we wouldn’t be able to show them.
That is just one example, but I hope that Chevy gives us the option.
(Quote)
August 17th, 2009 at 4:36 pm
Volt Math is Monkey Math, not to be confused with Cave Man Math or 5th Grader Math
(Quote)
August 17th, 2009 at 4:41 pm
When you hook your Volt to the Grid, the local Power Utility will have automatic authorization to harness any energy stored in the Volt for the greater good of the local community. This may delay immediate charging while the smart meters determine a more satisfactory time to resume normal charging activity to balance energy loads within said Grid. Be advised that all Volts will be heavily monitored by OnStar’s sophisticated data acquisition system for proper use and delegation of redistribution authority within approved GM Grid partners.
(Quote)
August 17th, 2009 at 4:48 pm
No doubt Government Motors is having a difficult time engineering proper firmware to give the illusion of smooth switch between the ICE and T-Batt sources. I don’t buy for a New York minute that they are even close to solving their self-made problem in choosing the older series-hybrid design.
(Quote)
August 17th, 2009 at 4:51 pm
It will NOT be seamless in a Volt. This is physics, pure and simple. They can “feather” all they want. Ain’t no feather gonna hide the power of physics.
(Quote)
August 17th, 2009 at 4:52 pm
I’m really stoked about this car coming to market.
I have not seen an adequate explanation of how GM will handle the significant difference in the acceleration characteristics between the battery powered motor, where 150 hp is available and full torque available at 0 rpm, and the ICE powered motor, where only 100 hp is availble at high rpm? When battery powered, the car will accelerate like a chevy cobalt, but accelerate like a chevy metro when the ICE powers the Volt.
This difference in performance will frustrate the driver and could be unsafe for passing conditions.
(Quote)
August 17th, 2009 at 4:54 pm
Drop your racist Prius hate. It has no place in this forum. ;-(
(Quote)
August 17th, 2009 at 4:57 pm
It’s known in the industry as Ford Stink for a reason. There is a Doofas Ford forum on the Net that is calling your name. Go Quickly. Step away from your trailer trash pewter and Leave. We don’t need your kind here. This is a GM enthusiast site.
(Quote)
August 17th, 2009 at 5:02 pm
Last i done heard the GM engineers do not subscribe to Test Driven Development (TDD). It is a hyped technique used to shield incompetent developers from themselves. Much better to just hire competent programmers that only need to code once and get it right the first time. If you want self-healing code suggest you look to IBM mainframe technology circa 1970s. Still rock solid and widely used. Sorry but the Mainframe is not even close to dead.
(Quote)
August 17th, 2009 at 5:04 pm
If you want Bulletproof SW look to the shining ORACLE….bulletproof indeed.
(Quote)
August 17th, 2009 at 5:07 pm
GM is trying to give the ILLUSION of smooth transition. Think of it as a Virtual Transmission. And Yes, those are 230 Virtual MPG (not real MPG).
(Quote)
August 17th, 2009 at 5:13 pm
At least one thing that concerns me about the Volt, if its that difficult for GM to get it right at the factory, will my local dealer be able to do the same ? With mechanics lacking experience with the Volt will any of them be able to tune it ?
(Quote)
August 17th, 2009 at 5:13 pm
Nope, you cant jump start a Volt.. then again the battery is 37 times bigger than a normal 12v car battery..
You could probably charge the main battery for a few minutes with a portable generator.. enough to get the genset started.
Will GM let the owner extract the last little bit of juice out of the battery once the gas runs out?.. perhaps crawl to a nearby gas station at the risk of damaging the battery.
(Quote)
August 17th, 2009 at 5:24 pm
You forgot the “a n a l” probe that onstar uses to gauge the drivers body temperature while driving.. thats how the AC is controlled you know.
(Quote)
August 17th, 2009 at 5:30 pm
That then should make the charge sustaining mode the “AD” mode; After Depletion. Sorry, couldn’t resist.
Peace and 73
(Quote)
August 17th, 2009 at 5:30 pm
Uhmmm….there is still a year before release…hello……
(Quote)
August 17th, 2009 at 5:38 pm
When I teach technicians the different angles-of-attack for any problem on an ICE, there is a logical sequence that I teach for all makes and all models (that connect to a Genisys, which is 99% of them all).
Making use of whatever conditions that you have at hand (or are imposed upon you) to plan the diagnostic sequence is a must.
Here, where essentially “there is a five legged stool” of balance difficulty, the first thing to judge is what can be taken advantage-of to remove from considerations temporarily, one or two of those “legs”, so that the addressing of only 3 of those legs need be performed at first.
The first 5,000 Volts sold ought to have all the typical exemptions which small manufacturers enjoy so that any of the “under 5,000 units sold” exemptions might not at first need to be addressed so that the remaining co-variables can be more easily be perfected in concert with one another.
Three dimensional programming (and diagnostics) are far easier than five-dimensional programming. (I do not have five dimensional diagnostics, just three (waveforms at a time) for experienced techs, and four (waveforms) for exceptional ones.)
A second way to remove a second co-variable (temporarily) from the initial software workload in order to make the work easier, is to get at least three demographic groups working independently with actual test drives of the genset in operation with many “alpha/beta” software routines for ICE in several workload configurations. This would help to formulate expectational vocabularies that will be needed well in advance of release.
A third way to help with this process is to not have any “hard preconcerted rules” which could slow research in the first place. While perfection and perfect silence are exceptional goals, the longevity of the components are also in play here.
Having most autos nowadays “never give indications” of ongoing expensive damages happening, (which happens entirely too frequently as we all know) so that the customer will not become unpleasantly surprised, puts all the onus and credibility-stresses on both the dealership service department as well as the independent technicians out here in the field eventually, and, that is not really what the customer wants. The customer WANTS noise when noise is the only thing that will tell them that “it doesn’t sound right”, “it sounds different than it used to”, “it is making a noise it didn’t make before”. “Didn’t make before” is our clue that most buyers would be delighted to learn everything they could about their Volts, and, what are the “correct” noises that it should make.
Some people actually WANT very different noises. THOSE ARE YOUR TESTERS. (Perhaps Tag, nasaman, me (if I do say so), and many others who would be wonderfully-intrigued with different operations that herald our new GM Volt Age.
(Cap’n Jack too if he behaves).
The customer all too often just does not believe that a large and expensive problem have sometimes occurred, since nothing went “boom”, or, nothing unpleasant happened on the dashboard to warn the owner. (Yes, I know that the MIL light has been ignored for about 40 years now, but, a highly detailed message on the screen for any given situation ought to be presented, especially where abuse has taken place. (”My son/daughter would never do that!”). Placing abuse-responsibility where it squarely belongs is what Volt ought to do, it seems to me, to prevent false “whining” and slanderous blame against GM, the dealership techs, and eventually, independent techs, with dates and times as fault codes, and composite “calculated systems load %” for all systems, that can not be cleared, *ever*).
I really think that most Volt customers would be happy to have something that sounds different, (especially if it pertained to helping systems last to the maximum MTBF (mean time before failure). An educators software display would be outstanding, so that those of us who want to expand our social lives (esp. me), could get folks to go to dinner with us in our Volts, and, we could teach them to go buy one.
(Quote)
August 17th, 2009 at 5:40 pm
ICE powered mode is still full power, the Volt will accelerate the same in both modes.. top speed on level ground is 100mph with the battery empty.
The battery will supply extra power to reach the full 112kw level of acceleration.. yet the genset can only provide 50kw.
Its the magic of “average power” concept.
(Quote)
August 17th, 2009 at 5:43 pm
http://green.autoblog.com/2009/08/17/one-lap-only-fisker-karma-takes-on-laguna-seca-in-public-drivin/
Video of the Fisher Karma EREV doing a lap in the Laguna Seca racetrack. They are getting close to production.
Sounds pretty loud with the tire and motor whine.
(Quote)
August 17th, 2009 at 5:56 pm
The battery reserve (buffer zone) will fill in the extra 50 hp.
The more accurate question is: What happens if battery reserve has run out –now how do you deal with the performance difference?
I would suspect they either:
A. Bump up the buffer zone so that it’s big enough that you never have a problem (i.e. when ICE comes on after customer depletion, it starts charging the battery to a level higher than we’ve been told.
or
B. They limit the volt’s performance in Electric only mode to no more than what the genset could put out. (performance spec’s only up to the level of the weakest link)
I would think any sort of “power fade” situation would be a liability that the lawyers would not sign off on.
/ Genset will not put out the same power as the maximum from the ICE. There will be generator efficiency losses — the big question is, how much?
(Quote)
August 17th, 2009 at 5:57 pm
You guys are in for such a shock.
I still believe that “50″ is a lowball mpg made for the general purposes of underpromising and overdelivering.
We’ll see.
(Quote)
August 17th, 2009 at 5:59 pm
Awesome! It’s unbelievable how quickly they made that Karma and that it will be to market next year. The Volt was far along the concept process before the Fisker company was even formed. Should be a hell of a shootout between the Karma and the Tesla S.
(Quote)
August 17th, 2009 at 6:00 pm
Why would you want to use petrol to charge the battery? the engine will come on when you need it, and you can charge at home for a fraction of the cost.
(Quote)
August 17th, 2009 at 6:03 pm
Hey Herm,
Boy are you right! Not my choice at all. But others would go for it I’m sure. WTW? (What’s The Warranty?)
(Quote)
August 17th, 2009 at 6:03 pm
Ok. Well, never mind then.
(Quote)
August 17th, 2009 at 6:05 pm
Currently the Volt cannot be used to power other items – so you will not be able to draw energy from it for the grid (also you’d need to modify your power box at home to do this).
If GM wants to waste thousands on each car per year for 2 way satellite communication to monitor the cars performance, go right ahead. They will know exactly how to fix the car at the dealership if something goes wrong without me having to say a word!
(Quote)
August 17th, 2009 at 6:29 pm
I still think Frank is the man.
The software they write now will give them copyright, presumeably, on that transition technique.
Row faster slaves…
(Quote)
August 17th, 2009 at 6:32 pm
Ed M –> It is a different matter to put things back the way they were than to design them to be the right way in the first place. I’m confident that mechanics, with training, will do a good job.
(Quote)
August 17th, 2009 at 6:37 pm
Herm—Or put in some gas and start the ICE?
(Quote)
August 17th, 2009 at 6:48 pm
I’m sure GM has a lot more bureaucracy than Fisher, it will take them lots longer to do anything.
Electric cars lend themselves well to small shop manufacturing.
(Quote)
August 17th, 2009 at 7:02 pm
The tuning in a Volt is just a matter of the mechanic connecting a cable and reprogramming the computer.. the program will still be written at GM headquarters by trained engineers.
I was thinking the other day that the Volt engine will run so seldom that it may never need a tuneup or filter change. GM could even formulate a special motor oil that would be good for the life of the car.. probably with a bigger filter and extra anti-acid additives. The computer would keep track of the engine run time and set the oil change interval by that.
The average driver does 12,000 miles a year, divided by 365 it works out to 32 miles per day.. in theory it could be done by the battery alone.
Regen braking will do most of the braking.. so the brake pads should last many thousands of miles also.. perhaps even the life of the car.
(Quote)
August 17th, 2009 at 7:09 pm
2 cents $
41 mpg on hwy with ICE only
44 mpg in city with ICE only
Print it. Save it. Throw it in my face later on…
(Quote)
August 17th, 2009 at 7:10 pm
You would have to drive the Volt very aggressively to force the car into limiting acceleration once the battery is empty.. I really dont think its possible outside of a racetrack.
The Volt will not be able to do 100mph with a full passenger load going up a hill.. it will behave just like any car, you can have the pedal all the way to the floor and it just wont go any faster.
(Quote)
August 17th, 2009 at 7:15 pm
Well… See, thats the rub.
I think alot of the disagreement on the actual figue comes about because we all use different definations when we talk about Charge Depleted Highway Mileage.
Some define it as 70 mph Constant Steady State Travel
For this case, I think 50 mpg is a high number, 40-45 mpg is more likely. And it wouldn’t look that much better than say a Prius Hybrid number. Because Steady State Travel essentially allows any motor to act in the way the GM Serial Hybrid motor will.
Some define it as Driving Cycle US06
For this case, I think 50 mpg is a reasonable number. Numerous high bursts of speed up to 70 mph, lots of starts and stops. 45-50 mph if we throw in some Heating/Air Conditioning loads. Should look better than a Strong Hybrid, since more time will be spent in “constant” mode in a Serial versus a Parrellel system.
Some define it as HFES, or EPA Highway driving
For this case, I think 50 mpg is a low number, I could see 55 mpg. Average speed is only 48 mph, with a gentle peak of 60 mph. Serial Hybrids should only small improvement over Parrellel system, since there is not significant things to buffer against.
Some people of course think “normal” HWY driving is 75 mph+ with constant ups and downs on a 90+ degree day with the radio blasting. Painful for any auto…. not sure why we should expect a Volt to get even 40 mpg in that situation.
(Quote)
August 17th, 2009 at 7:16 pm
I agree here, turn the radio on and the generator will run at the “sweet spot” for the best mileage. turn the radio off and the generator will mimic the throttle position. Turn the radio on with the volume at zero you will be able to hear the gen-set at peak efficiency, if that is what you want to do. I know I would give it a try.
No transition will be truly imperceptible, however it will be darn close to seamless. You just do not want to upset anybody, for those that are hypersensitive and easily distracted, turn the radio/stereo off.
In the past it has been argued that you can get better mileage by turning the radio off. You know the increased drag on the engine caused by the generator generating an amp or so for the radio.
With some of the new high power systems there may be something to that?
Anyway I just want to say I get better mileage with the radio on!
(Quote)