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GM Unveils Second Propulsion System for Chevrolet Volt: A Fuel Cell Variant

Cutaway drawing of the Volt fuel cell variant. Click to enlarge.

At the Shanghai Auto Show, GM unveiled a second propulsion system for the Volt concept under the aegis of the E-Flex electric drive family: a hydrogen fuel cell variant that uses GM’s new fifth-generation fuel cell system as its primary power source.

This second variant of the E-Flex system combines the new 80 kW fuel cell stack with an 8 kWh (50 kW peak power) lithium-ion battery to provide up to 300 miles (483 km) of petroleum- and emissions-free electric driving. The Volt fuel cell variant is plug-in capable, adding up to 20 additional miles (34 km) of range each time it is charged.

The two Volts, battery-dominant with ICE range extender on the left, fuel-cell centric on the right. Click to enlarge.

Unlike the first Volt propulsion system, which is battery-dominant with a small combustion engine range extender, the second system is fuel-cell centric, and uses a blended operating strategy to augment its range and power with a battery pack that is half the size of that in the first Volt.

A different configuration under E-Flex in which a smaller fuel cell would function as the range extender to a larger battery pack is also possible. (This is the approach Ford took with its HySeries concept. Earlier post.) However, this is not the design that GM implemented in the second variant of the Volt.

The E-Flex system is a flexible all-electric production vehicle architecture that can be configured to run on electricity from a number of sources.  It was first shown in January at the North American International Auto Show in the Chevrolet Volt concept vehicle. The first Volt concept is a plug-in series hybrid electric vehicle that has a 40 mile all electric range and uses a small bio-fuel engine with a generator to extend its range to 640 miles (1,030 km). (Earlier post.)

We think electrically driven vehicles are really going to be a big part of the solution to the energy and environmental challenges that our vehicles face.  We’re talking about purely electrically driven vehicles, not a hybrid, not mechanically driven.  And this really sets the stage for diverse energy sources in simpler vehicles.

When we talk about electrically driven vehicles, we're really talking about what GM calls E-flex.  It has a common drive architecture, electric drive component, and electric drive architecture.

The key is to be able to create and store electricity onboard the vehicle, and you can store electricity obviously by plugging the car in and storing electricity in a battery.  And you can create electricity by running an engine generator or by using a fuel cell.  So the key enabling technologies here are engines and generators and batteries and fuel cells and hydrogen storage and the plug in capability that they offer.  And then because electricity and hydrogen can be generated from a range of energy sources, we can have all that diversity with a very simple, common E-flex electric drive architecture, so that really helps from a business standpoint. 

—Larry Burns, GM Vice President Research & Development and Strategic Planning

The fuel cell variant shares many parts with the first version of the Volt, such as the front electric drive component.

The 5th generation fuel cell system in the Volt. Click to enlarge.

GM’s fifth-generation fuel cell system is half the size of its predecessor, and provides the same power and performance. The fourth-generation system currently powers the Chevrolet Sequel concept vehicle. To double the specific output of the fourth-generation system, GM worked with different material sets and then improved efficiency and improved yield from each square inch of material inside the cells.

Our improvements are in management of all of those gasses and the water flows, [and] the selection of the materials to make that whole membrane electrode assembly center. It’s a system. The real key is in the controls.

—Larry Burns

The Sequel stores 8 kg of hydrogen and delivers a range of 300 miles (483 km). The fuel cell Volt—a lighter vehicle—will also deliver a range of 300 miles, but with only 4.0 kg of hydrogen (75 miles/kg) stored at 10,000 psi in two Type IV tanks.

The front drive motor offers a maximum 70 kW of power, with 250 Nm (184 lb-ft) of torque. The Volt fuel cell variant also showcases GM’s two third-generation wheel hub motors, packaged inside the rear wheels to add torque for all-wheel electric drive capability. The new motor technology reduces mass and produces more power (25 kw and 500 Nm /368 lb-ft per motor) compared to the first generation shown in 2003.

The fuel-cell Volt accelerates from 0 to 60 in 8 to 8.5 seconds, and has a burst top speed of 120 mph, with a continuous top speed of 100 mph.

A variety of other technological advancements and lightweight materials contribute to the efficiency of the Volt. With an estimated curb weight of 3,500 pounds (1,588 kg), it weighs 30% less than the Sequel. The fuel cell propulsion system is packaged entirely under the hood and is equivalent in size to a four-cylinder engine with automatic transmission.

The Volt also features molded GE plastic panels on the fenders, window glazings, instrument panel and steering wheel, which offer between 30% and 50% weight reduction per part. The car is fitted with low rolling resistance tires.

The global economy is going to grow 3% or 4% per year, and there’s a correlation with that economic growth to the demand for energy growing at about 2% per year. 

You know you compound 2% over 10 years, that’s 25%.  That puts you right in the range of the efficiency gains that you get from a hybrid, right in the range of what it would be energy efficient-wise versus a gas engine, and right in the range of what most people think can be teased out of the internal combustion engine going forward.  So we really need to look at alternatives in addition to just efficiency improvements to solve this problem.

So we really think now is the time to face the reality.  We have to find solutions to the energy and environmental challenges that automobiles face.  We have to do it in General Motors simply as a matter of business. If we don’t, there are real concerns about the growth of our industry being capped and that’s not a good thing for our industry.

And at General Motors, our strategy is pretty simple.  We want to displace petroleum, displace oil, reduce the amount of oil that’s being consumed, and we think the key to doing that is through energy diversity.  By having a wide variety of energy pathways made available for automobiles, we can grow our business and we have the chance of growing our business sustainably going forward.

We’ve become increasingly confident that we can meet the automotive competitive targets that we've set for the [hydrogen fuel cell] technology, $50 per kilowatt, 150,000-mile life, with a 300-mile range. But before this technology can be made widely available, governments, energy suppliers and infrastructure companies around the world need to collaborate with GM and the auto industry to develop a market for fuel cell vehicles and hydrogen fuel.

—Larry Burns



“We’ve become increasingly confident that we can meet the automotive competitive targets that we've set for the [hydrogen fuel cell] technology, $50 per kilowatt, 150,000-mile life, with a 300-mile range.”

So the 300 mile range is a done deal. It would be really interesting to hear how far they have come on the other two goals. Speak up if you know.


Engineer Poet-
I was referring to a recent article on this site entitled, "Toyota to put Fuel Cell Vehicle into Demo Project in Japan" as an example of an abscence in anti-Fuel Cell commentary vs. this article and others. I probably should have articulated that better--my fault. It has just been my observation that whenever GM seems to do anything, let it be FCV's, Volt concepts, E85, or you name it, they get a lot of searing flack, yet when Toyota does it, little or nothing gets said. Refer to the article I mentioned above. At the time of this writing, there was one comment posted. There are no comments about how foolish Toyota is to be wasting their time on Hydrogen. Nobody calls Toyota's projects "Vaporware". Nobody criticizes Toyota for working on "Fool Cells". Had that been a GM related article, there likely would be floods of comments calling it "Vaporware", "Fool-Cells", "smoke and mirrors", etc. You gotta be seeing the same thing I do here, where people are always taking shots at GM, and when Toyota does the same thing, the bashing comments are mysteriously abscent. That's called hypocrisy where I come from. You pointed out that few people here are fans of Tundras. But I see that those same people will neglect to negatively point the Tundra out in their comments, yet are more than happy to drop a shot at GM for making Big Pick-ups. Mark A. made a good point in a post above about the Tesla range decrease article. Had that been GM making a concession, we would never hear the end of it. Mark points out that there isn't a level playing field here, and he's right, there's not. I'm not saying GM can do no wrong either, but when I do see them doing things like the Volt, that's something we (as green car advocates), should get together on and promote.


Thanks for just proving my point.


I see you still have not figured out what the volt realy is...
Gm ewawntly talked about the rwd car...

The volt is the new rwd heavu sedan... in short its future is as a cop car and civ versions of said car,

I suspect a beefed up version is planned for testing as the 2015-2020 cop car.

Oh and because the fuel cell is smaller now they likely can make a cheaprt compact version down the line.


$4000 cost versus $4000 MSRP (for the Rob).

With the equipment I deal in, we are looking for 30 points GP minimum from Landed cost (net-net). If FOB is $4000 and landed costs are maybe 1% then to make that 30 points of GP would be around $6286 cost to the dealers. Typically, my equipment tends to have 40 points of GP for the dealer for an MSRP of nearly $10,500. Granted, a dealer could choose to take less profit, but his operating expenses (lease, utilities, taxes, employee salaries, insurance, etc) have to come from somewhere.

So if $10,500 premium is not expensive to you...


Not trying to be disrespectful but who are you addressing? You said, "GM ewawntly talked about the rwd car..." Huh? What does that mean?


I think allot of the negative comments stem from the fact that Volt is a show piece that comes with allot of hot air, while the Toyota is ON THE ROAD.

Who do you think will have one for the market first?

At least their fuel cell package appears to be improving, it appears to be on pace with other automakers in the size/output/weight.

I want GM to kick #$%, I wish I could be proud of the US automakers, most of my family and friends rely on these bozos for survival.

But given GMs history the Volt will be too late and not quite right. GM please prove me wrong.


My biggest fear is that the Volt will make it to market, it will sell well, but the accountants tried to squeeze 10 cents out of a critical power-train wire connection. Then all these Volts will be stranded at the dealers waiting for repairs every 10k miles destroying the image of an "alternative" fuel car. Then it will take the next 20 years to convince Americans that it is OK to buy something other than a pick-up with a six liter gas motor.

I guess that is perfectly acceptable for Toyota to look into Hydrogen because they can do no wrong.

Toyota can afford to look into Hydrogen because they already have a successful answer to the problem that GM can't address with anything other than vaporware.


What I see in this article is GM trying to stick anything into this vehicle that they can make money
on in maintenance.
That is where GM makes BIG bucks. A car you cant fix
with small bateries so you cant run on electric only.
An ICE for this car or Fuel Cell is definitly something
you will have to drag into the shop and pray to the GM mechanic to fix. This is what I think GM is working on.

The statement GM has been tossing around that the
batteries are not ready does not hold water with
the advent of the Phoenix truck and Tesla.

So more ad-ware from GM doesnt shine there image much to me.



Bill W:
I have a lot of concern for the reliability and durability of the Future Volt too. The scenario you mentioned send chills through me. A collosal failure could strike a deathblow to the EV's future. I pray to God in Heaven that they can get this right.

Greg woulf

The Toyota on the road is a waste of valuable battery material meant to make non-technical environmentalists feel like they're doing some good.

I hate GM for their lack of success at times, but they have done a lot of research into electric vehicles. The motor and control system that's in the Tesla come indirectly from that research. The EV-1 is famous because it was pretty good after all. I've seen the numbers and no company could have made the EV-1 work. It wouldn't have sold, it would have failed, that's the bottom line.

If you offered the EV-1 today it would still fail. A $60,000 car that goes less than 80 miles on a charge with a very short life on a very expensive battery pack, isn't going to win the hearts of drivers.

There's a lot of people to blame for EV's not taking off, but GM isn't at the top of the list.

This car is the first to say we're going electric, period, and we'll make a flexible platform so we can fit any source of electricity into the car.

3,500 lbs isn't so high a curb weight. The Tesla just learned the hard way that to get the safety you have to add the weight.

If you want to blame someone look in the mirror. No company in the U.S. can compete, and it's not because they're stupid. We Don't support the research, and we don't work cheaply enough to be competitive. That's the bottom line.

Keep your eyes on the prize, and not on your pride and you'll see that this car is going in the right direction whereas many others are not. Flexibility is key right now.


I am with you on that!!!!

I light of how GM managed technology such as engine cylinder cut out(Cadillac V8-6-4), diesel engines (Oldsmobile V-8) and electric cars (EV-1) in the 80 and 90's, I hope they stick with this and make it world class.

They could have been way ahead of the competition in the 00's if they worked on these things rather than tossed them out. We should be reading about how the new mild hybrid Colbalt with a 4-3-2cyl diesel engine is the top car on the EPA MPG list, the top of 5 GM cars to make the list.

Just Dreaming. :>


I think most of the problem is GM have a history of making not
terribly good cars , from my own stand point I have only ever owned
one GM car , and I am afraid it was a bag of **** , it spent most of its
time in the garage being fixed , and was eventually scrapped at three
years old after covering 130000 miles , so I have never gone down that
path again , I think also GM are basically dishonest and have no intention
of ever producing the volt .
On the other hand I also have an 18 year old Toyota land cruiser which
is still going strong , costs very little in maintainance and will still return
30mpg on a run , so when it comes to replacing a vehicle I think you can
guess which way I will cast my vote !


I'll believe it when I see it.
How about getting the first Volt on the road with feasible technology and infrastructure?
Another diversion tatic by GM to buy time while they keep unloading big SUV's on us?
Nothing in their recent history convinces me they are serious.
We'll have to hope for Japan, Europe and Start-up's in the USA.


New Cadillac SRX4 as reviewed by the Sunday Times in england
last weekend, official fuel consumption 14 mpg, test got no more
than 10 mpg , reviewers quote " this car could well turn out to more
expensive to run than the Iraq war ". This car sort of sums up GM´s
approach to the enviromental problem!



I think that GM could sell the EV-1 right now. At least a limited number, look at Telsa's success, that is the EV-1 crowd. Plus, 10-15 years of development would have made it a better car. Heck, during the EV-1's short life it had already had a significant battery upgrade that increased the range to double what you quote. At least that is what I have found. see

"We" not working cheaply is not an excuse either, most of the latest tech cars are designed, tested and manufactured in Europe, Japan or the US, all very expensive places to operate.

Unless you mean the guys at the top that make multi-millions making the decision not to invest in research, mis-manage employee benefits and give each other a bonus. Then I am with you!!

Harvey D.


GM has been selling 'BIGGER IS BETTER' 'MUSCLE CARS' (and not so small trucks) for almost a century and is still at it with the Volt. Changing GM's ingrained attitude is as difficult as changing our acquired addiction to 'BIG-MANIA'.

Fortunately, many more of us are waking up and may no longer fall for this PR and buy lighter more efficient cars such as the Toyota Prius II and III.


Your concern about the (Hydrogen) Volt reliability may be justified. Both, the new battery pack and the fuel cell will most probably have high early life failure rates, specially if GM over-accellerates the introduction of those two technologies.

A Volt PHEV with a proven light weight flex-fuel ICE generator and a 15 KWh to 25 KWh high performance battery pack would be a better idea, at least for the first 5 to 10 years or until such time as the hydrogen infrastructures are in place.


When I visit family and have to drive US designed/built cars/trucks, it makes me more appreciative of my nearly 20 year old "foreign" car every time.

Although I have to admit the Cadillac CTS was a revelation. I hope that continues.

Mark A

What a lightning rod GM is on this site. Alot of folks sure like to hate GM, even with a feel-good story like this. I am in disbelief. This is a concept car that appears headed for production in some fashion, when the technology and infrastructure all coincide. Everyone will win if and when that happens. Every automaker has concepts, even Toyota. Some dreams can come true.

GM has had some failures over the years, but perhaps we should look forward and hope for mostly good things instead of associating todays dreams to past failures.

But GM has had lots of hits, and homeruns, over the later years. The later Corvettes could hit 28-35 mpg, while still going 0-60 in 5 seconds or less. Say what you will about SUV's and trucks, but GM made/makes some of the best. And people have kept buying (voting with their checkbook). GM is also a leader in hybrid bus design, and alot of that know-how just may translate over. Many people buy vehicles for their utility, not for their passion and "greencarness" as most of us on this site.

The hydrogen economy is coming, in my opinion. Batteries and fuel cells will ultimately come together, along with ultracaps. I dont fully understand it all, but am excited about our future transport. But yes, Schmeltz and BillW, one bad EV offering from a GM, Toyota, Yugo or Kaiser (yes Yugo and Kaiser are in jest) will taint everyones perception of EV's. Everyones expectations are so high, and we cant afford a mistake. Thats why the automakers are so hesitant. Get it right, right out of the box.


In reference to the Cadillac SRX4 you mentioned, thanks for your comment because it once again underscores un-warranted GM bashing in my viewpoint. The Cadillac you mentioned, (which incidentally has nothing to do with this article about the Volt), will probably be low in sales volume, therefore probably having little net affect on the environment. Moreover, you may find this hard to believe but the Asians are actually leading in the charge of the horsepower war. Toyota is busy showing off its new Lexus LX 570 sport utility vehicle, which replaces the 470. The current 470 weighs 5,400 pounds, can tow 6,500 pounds and has a 268-horsepower V-8. I never heard anyone say the previous model was underpowered. The new one, which reaches dealers early next year, will have 381 horses, a whopping 42% increase.

Just about all the small cars from companies such as Nissan and Subaru are getting bigger and punchier. I expect the new Honda Accord coming this fall will get a power boost too. Even Korean Hyundai is readying a big 300-plus horsepower V-8 for a new sedan.

From Europe, we have the new Porsche Cayenne SUV with a 290-horsepower V-6 replacing the 250-horsepower engine, and a V-8 with 385 horses versus 340 in the previous model. The twin turbo V-8 Cayenne moved to 500 horses from 450. The new Audi R8 is a new sports car with 420 horsepower, and almost everything, from Minis to little Volkswagens, are getting power boosts. Bigger, faster, and more powerful is not just coming from Detroit, but the Asians and Europeans are leading the charge.

It's laughable how you don't include mention of these cars in your bash above.

Greg woulf

The EV-1 would not sell to the masses, not the way it was, not with the batteries it had. It would sell to a small audience that would bicycle everywhere if they could.

The car cost over $60,000 to make, the batteries started out at around 100 miles and the range shortened fast. They took a long time to charge and a new battery cost over $20,000.

There's a saying about turning a swine's ear into a silk purse and it goes for the EV-1. I wish people would just get over it and look at reality with open minds.

Judge GM on their average mileage, which is crappy, judge them on their lack of hybrids being developed and judge them on their lack of quality. Those are all fair criticisms in my opinion.

Let go of the biased opinions based on a sensationalistic film and judge the product that comes out on it's own merits.

I'd never have guessed that GM would be the first to go the direction I see as right, but I think they were. An electric motor, with all it's efficiency to run the car, and a flexible platform to accept all power sources.

I hope all of the other car manufacturers start building with power flexibility in mind. My hope is that Battery electric is the way to go, but I question how large a supply of Lithium will be needed to satisfy the world demand. I hope that we can go battery electric and that's it.


Greg Woulf:
Agreed and well said.

tom deplume

So far H2 fuel cells are showing themselves to be just as complicated as internal combustion engines with none of the advantages of ICEs. ICEs can use a wide variety of liquid and gaseous fuels with only small adjustments. The presence of atmospheric CO2 does not spoil an ICE. ICEs are more efficient under heavy loads where as electrical devices become less efficient as load increases and that includes fuel cells. Experimental ICEs have reached efficiencies of nearly 80%. People have been working on ICEs and fuel cells for similar amounts of time but we still haven't figured out how to manufacture them as cheaply as ICEs.



You don't understand the Japanese working culture. They are paid much less than we are for similar jobs. The engineers from Japan assigned to work in the US are paid much better than their peers back in Japan. Even then, the US Engineers are paid MORE. The American VP of one division is paid around 3 times as much as the Japanese President of the company.

In Japan, you work for the good of the company and not for yourself. Therefore, they are typically paid less and expected to put in overtime without compensation if the needs of the job demand it; unlike in the US.

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