DailyTech - GM Displays Second Iteration of Its E-Flex Architecture

Submit News

Auto GM Displays Second Iteration of Its E-Flex Architecture
Brandon Hill (Blog) - April 20, 2007 2:21 PM

E-mail

del.icio.us

37 comment(s) - last by TheGreek.. on May 14 at 4:57 PM

Images courtesy of AutoblogGreen

GM showcases 5th generation fuel cell technology

General Motors used the Shanghai Auto Show to display the latest version of its E-Flex electric architecture for automobiles. The first version was shown in the all-electric Chevrolet Volt concept car. The second version of the E-Flex system makes use of GM's 5th generation fuel cell technology.

"The beauty of our E-Flex strategy is that it allows us to package various propulsion systems into the same space depending on what energy is available locally," said GM VP of Research and Development and Strategic Planning Larry Burns. "It also provides flexibility in the sources of energy. We can obtain hydrogen or electricity from a myriad of renewable sources - wind, solar, geothermal, hydroelectric and biofuels - or from traditional sources such as natural gas, clean coal, nuclear or even gasoline."

The new Chevrolet Volt Concept using the hydrogen fuel cell E-Flex system features a 4kg hydrogen storage tank, 8kWh lithium-ion battery pack, 70kW motor for the front wheels and two coreless 25kW hub motors for each of the rear wheels.

The E-Flex system provides a driving range of 300 miles. Thanks to its plug-in capabilities, the system can manage an extra 20 miles of range if the vehicle's batteries are fully charged before driving off. GM predicts that the vehicle can accelerate from 0 to 60MPH in 8 to 8.5 seconds and will have a continuous top speed of 100MPH. The Volt will also be able to increase that top speed to 120MPH in short bursts if necessary.

"Our progress has made us increasingly confident that our fuel cell propulsion system will be automotive-competitive," Burns continued. "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."

Comments

Threshold

Username
Password
remember me

This article is over a month old, voting and posting comments is disabled

Maintenance costs?

By Mitch101 on 4/20/2007 2:28:24 PM , Rating: 2

What is maintenance on something like this or even hybrids?

Oil Changes? Motor replacement? Battery replacement? Etc.

RE: Maintenance costs?

By Oregonian2 on 4/20/2007 2:35:46 PM , Rating: 2

Ah.. the details. Plus how much to buy it up front.

Like most new high-tech stuff, wait until they make a few million first then take a look. :-)

Parent

RE: Maintenance costs?

By TimTheEnchanter25 on 4/20/07, Rating: 0

RE: Maintenance costs?

By IsDanReally on 4/20/2007 3:28:15 PM , Rating: 3

Keep in mind that in many states all hybrids have a 10 year battery warranty. This is because the battery is an emissions system, and so all states that follow California or New York’s standards on the matter have the extended warranty on all hybrid components.

Parent

RE: Maintenance costs?

By Playit on 4/20/2007 6:17:00 PM , Rating: 4

California requires a 10 year warranty on the battery while most other states provide at least an 8 year warranty. However, to the best of my knowledge (and I have researched this) there haven't been any examples of batteries failing due to wear. The only replacements have been due to physical damage such as a an accident. Most of this is due to the fact that Hybrids use the battery pack very differently than electric cars. The battery is generally kept inside a range of charge and its temperture is seperately maintained from the cabin temp. There are only limited high milage examples of Hybrids, but those that are available indicate that the battery will run maintance free for the life of the car.

None of this is true for electric cars however.
-M

Parent

RE: Maintenance costs?

By FITCamaro on 4/22/2007 6:34:45 PM , Rating: 2

Anyone care to explain why this post was voted down?

Parent

RE: Maintenance costs?

By Grast on 4/23/2007 11:31:56 AM , Rating: 2

It was voted down because of two reasons.

1. You were offering an opinion that hybrids are not the wonderful solution they claim to be.
2. One of your statements was incorrect. The batteries are typically replaced every 10 years.

Later..

Parent

RE: Maintenance costs?

By Oregonian2 on 4/23/2007 8:38:20 PM , Rating: 2

Although more of a predicted typical. Hard to have a real typical when there probably hasn't been even one data point yet.

Parent

RE: Maintenance costs?

By CollegeTechGuy on 4/20/2007 2:41:50 PM , Rating: 2

Why would you ask a question like that for something that is in experimental stages. GM doesn't even know what the answers are to those questions.

Parent

RE: Maintenance costs?

By Mitch101 on 4/20/2007 2:45:22 PM , Rating: 2

Let me specity hyrbis and existing ones today forget this future design.

In general what do Hybrids cost in maintenance and what maintenance do they need?

What do Toyota Prius do if anything on a daily maintenance schedule?

I know gas engines but know barely enough on hybrid requirements. Like Radiator Flushes? I would imaging a hybrid has one but I assume an full electric wouldnt. Transmission fluid changes, oil changes, tune ups, etc.

Parent

RE: Maintenance costs?

By Playit on 4/20/2007 6:56:01 PM , Rating: 5

I drive a hybrid so I'll try to answer this. The question is repeated elsewhere, but since this is near the top of the thread, I'll put it here.

The hybrid elements need very little actual maintenance. The motor is essentially maintenance free along with the battery pack.
The engine requires the same maintenance as a normal engine but in less frequent quantity. The engine essentially does less work per mile than a comparable engine. Ford suggests oil changes every 10,000 miles for instance, compared to every 7500 miles for the non-hybrid escape. Some components are more expensive however because of the lower volume of sales (air filters for instance).
You will have a few less options on repairmen. Even at my dealership I’m at the mercy of the Hybrid specialist. He doesn’t work weekends for instance. However the dealership has always worked around this by providing free rentals during the workweek because no Sat option was available.

Overall, I don’t think maintenance cost will be higher, and will probably be lower over the life because of the decreased engine usage. The engine is far more taxed in regular usage than the hybrid components.

Where the noticeable difference lies is with gas cost. I just filled up yesterday, 13 gallons for 410 miles. That’s 31.5 mpg. The real world non-hybrid equivalent is closer to 22 mpg. Also my Hybrid gets more mpg in the city and in traffic than on the highway. I can easily average 35-40 mpg during my commute and in traffic. My gas costs $3 a gallon yesterday or $38.05 per 400 miles. For the non-hybrid at 22 mpg you pay $54.55 per 400 miles. I drive 12,000 miles a year so I spend $1141.50 a year in gas. I’d spend $1636.36 for the non-hybrid. So I save $494.86 a year in gas.

As for the higher entry cost to hybrids, with my tax credit of $3000 my car was cheaper than the non-hybrid. In fact since the Hybrid actually drives more like a v6 than a 4cyld it was about $2000 than the equivalent. (Things like leather-heated seats are cheaper to add to the Hybrid for whatever reason). I couldn’t build a 4-cyld with leather seats, but either way with the tax credit it costs about the same as the 4-cyld option).

Fuel cell would be an entirely different beast. Electric motors are generally very low maintenance (and have been around for a very long time), but I can’t testify to the electricity generation portions as those would be novel.

Incidentally my 31.5 mpg is actually on the low end. I’m only a tank or two in on my engine. After it breaks in, and the battery pack breaks in, I’m told to expect another 2-3 mpg on average. In all fairness the average drops in the winter to something more like 27-30 mpg depending on just how cold. But regular engines drop in the winter too. But I think the 31.5 is a pretty good average over the entire year.

Feel free to ask if you have any more questions.
-M

Parent

RE: Maintenance costs?

By Lord 666 on 4/20/2007 7:49:11 PM , Rating: 2

Prius? Appreciate the detailed review, one of the more non-biased on DT. Was very close several times on purchasing a Prius. Still considering buying one to play with to augment the 2006 Jetta TDI.

However, hybrids are not fully baked yet. Assuming its a Prius, how is that sunroof working out? Since I live in a flood zone, on the cautious side about hybrids and flood. Lastly, I am honestly concerned about the long term exposure to higher electromagnetic radiation. Honda was too, they relocated the antenna on their hybrids to minimize interferance.

What you are forgetting is that hybrids also have higher insurance rates due to the complexity of systems and are totalled out at a much lower threshold. Search ebay and you will find salvage titled hybrids at a much greater rate than cars of the same year. In some states this does not matter, but in NJ and tri-state it can have an impact.

With the Jetta TDI just went away for the weekend and got a solid 600 miles to the tank (14.5 gallons). Routinely get above the sticker mileage of 36/42 (usually anywhere between 40-50mpg). Where I live in NJ, diesel is +/- .2 cents of regular.

Parent

RE: Maintenance costs?

By ninjit on 4/20/2007 8:42:07 PM , Rating: 2

He mentioned he has the hybrid escape not the prius.

Parent

RE: Maintenance costs?

By FITCamaro on 4/22/2007 6:40:09 PM , Rating: 2

Battery packs don't "break in". They slowly loose the ability to store a charge as you use them. Not gain the ability to store more energy. Nor are electric motors going to get more efficient with more miles on them.

Also with modern technology, engines really don't gain anything after the first 500-1000 miles. Tolerances are so close from the factory these days that the engine is ready the day you drive it off the lot. The only important part is changing the oil after the first 1000 miles to get any loose metal shavings from the break in period out.

And the tax breaks are going down now.

Parent

RE: Maintenance costs?

By Playit on 4/24/2007 12:24:25 PM , Rating: 2

The entire electrical system is computer controlled. From what I understand, the system is designed to restrict optimual performance during the "break in" period. So yes, as many other users have stated, performance does increase after a certain period of time.

As for the engine, Other users have again specified the 3 mpg gain they are getting. Over at GreenHybrid you can actually see every tank of gas users have with their cars. My car is not different. On my second tank of gas I'm getting 32mpg while my first tank averaged 28mpg. The value is actually increasing towards the end of this tank and I expect by my next tank I'll be averaging around 33-34 mpg.

The tax break is locked in when you purchase the vehicle. The decrease is due to sale numbers of the units in the country. Ford will not have a decrease any time soon, while Toyota has already had most of their decreases. The IRS website has an updated list that will tell you when the tax breaks change. Also, while the tax break will eventually decrease, in Model 2008 the difference between the Hyrbid and Non-Hyrbid versions also decreased. It would appear that the manufactuers are able to reduce the margin as they also make more units.
-M

Parent

RE: Maintenance costs?

By GoatMonkey on 4/23/2007 1:29:02 PM , Rating: 2

Good post.

I'd like to know how often the engine starts as you're driving. I'm assuming that the Escape works the same as the Prius where the internal combustion engine shuts down sometimes and you drive with just electric motors. Is that right, and how often does it happen?

Parent

RE: Maintenance costs?

By Playit on 4/24/2007 12:32:00 PM , Rating: 2

The shut down is due to speed and torque. The electric engine can drive the vehicle at speeds up to 40mph, but with less torque as the speed increases. At steady state on level ground I can drive without the engine up to 35 mph (the value increases up to 40 after the engine and motor break in). From the line I generally get to 5-10 mph before the engine cuts on. This is mostly due to my lead foot. Other users can accelerate without every having the engine come on. In my neighborhood and in parking garages or downtown my engine never comes on.

Other users have noted the gas usage per RPM of the engine and have found that it is actually very efficient in certain ranges (1000-2700 RMP). The actual sweet spot for this car is 40 mph where it gets 60 mpg. In contrast at highway speeds I get more like 31 mpg. The moral being that even with the engine on, at slow speeds you are getting very good gas millage.

Also of note, if not for the RPM gauge I would never know the engine is off or on. The 2008 is much quieter than earlier models and considering the radio, I never hear the engine. I can feel the engine, but only when stopped, and generally it is shut off at those times.
-M

Parent

RE: Maintenance costs?

By HVAC on 4/20/2007 2:43:21 PM , Rating: 3

Maint. is battery replacements and fuel cell cleaning or replacements. Fuel cells are subject to poisoning i.e. they can get crudded up like fuel injectors get varnish or cylinder walls get carbon buildup.
Batteries will need replacement depending on a whole lot of factors, the largest one for Li-ion being temperature.
Motors? Well, they will basically be magnetized rotors with bearings and copper windings around a lot of steel or iron. Copper windings can break due to movement caused by fluctuating electro-magnetic fields if they are not properly mechanically restrained. Bearings go out occasionally and if not permanently sealed, will need occasional greasing.
Time will tell whether fuel cell vehicles will end up needing more or less maintenance than internal combustion, but I think it will be less and will be centered around parts replacement and additives rather than fluid changes.
The thing about electric parts, though, is that they tend to just go pffftttt and not do a lot of vibrating, clanking, and grinding before they fail. This means redundancy is needed, but at a higher cost and weight.
I had more to say, but I'm tired of typing.

Parent

RE: Maintenance costs?

By Mitch101 on 4/20/2007 3:10:42 PM , Rating: 2

Thanks for that insight HVAC.

Anyone do a cost analysis on Hybrid maintenance and say 100,000 miles or years?

Now that I know a few things about what can go wrong and what needs maintenance what is the cost of this over several years. I do see a post on batteries and cost but overall. I think motor trend or consumer reports used to have a yearly maint costs area but I cant seem to find it.

Im googly impaired today it seems.

Parent

RE: Maintenance costs?

By mkaresh on 4/20/2007 4:16:48 PM , Rating: 3

The NiMH battery packs used by current hybrids rarely need replacement, so much so that it's not yet possible to estimate how often they'll require replacement. And the Prius has been available since 2001.

I conduct vehicle reliability research at http://www.truedelta.com, so I was wondering about this question myself. So I asked about battery replacements here:

http://priuschat.com/Where-are-the-older-Prii-Any-...

Over 300 people read the thread, and hardly anyone had a replacement to report. It seems that the software keeps the battery within a narrow range of charge to maximize its lifespan.

I have nearly 200 Prii participating in my research so far. If the batteries start failing, or anything else for that matter, it'll quickly become obvious. Nothing much to report on them yet.

Parent

RE: Maintenance costs?

By Anonymous Freak on 4/20/2007 4:28:24 PM , Rating: 2

Well, the Prius has 5000 mile oil changes, and every 30,000 miles there is a service that is only slightly more than an oil change.

No 'must replace the battery pack every 5 years' or anything. The battery is warranted for 8 years or 100,000 miles (10/150,000 in California,) and Toyota has said that they have run testing that had the battery lasting at least 150,000 without any noticeable degradation. Further, people who had the first-generation Prius have already run it over 200,000 miles, and report that as the battery loses capacity, you just get slightly worse gas mileage.

Parent

RE: Maintenance costs?

By togaman5000 on 4/21/2007 12:19:08 AM , Rating: 2

its nothing special, my mother bought a prius and she hasn't found any hidden fees. So far, the car only averages low 40s, because the emissions test for MPG isn't done correctly based off of how hybrids run.

Parent

Question

By mendocinosummit on 4/20/2007 8:04:55 PM , Rating: 2

A little off topic, but I have been wondering what would happen if all cars are running on hydrogen and it is well below freezing on a busy interstate. How much ice would form, if any?

RE: Question

By zsouthboy on 4/24/2007 12:17:30 PM , Rating: 2

What the hell?

Your question struck me like:

If you father was a washer and your mother was a dryer, how many pancakes does it take to cover a doghouse?

Parent