GM-VOLT : Chevy Volt Electric Car Site

General Motors provided an online media update as to current progress on the Chevrolet Volt and battery development program, moderated by vehicle chief engineer Andrew Farah and Voltec battery system manager Bill Wallace.  I and several actual journalists attended.  We were given the current state of development and the roadmap of the next 12 months leading up to the retail launch.

Overview
To date GM has built 80 pre-production IVers and 300 packs. Those vehicles are in testing 24 hours/7 days per week. Production and process validation builds will be made at Hamtramck from March through August 2010. From August 2010 through November 2010 manufacturing validation builds will be made.

The current prototypes have been tested cumulatively over 1/4 million miles. So far they’ve gone through hot weather trials, mountain trials and 65% long distance calibration buy-off rides. In December they will undergo a 300,000 mile three-lifetime simulator test. “We’re very happy where we are right now,” says Farah.

Battery Update
In December 2008, GM built its first battery pack based on their own in-house design and so far over 250 of these 4th and final generation packs have been made.  No further refinements will occur, others at GM are working on lighter next generation packs.

GM will bring it own battery pack assembly plant online in January and it is currently being built-out.   The first pack to be made there will happen in February 2010, and the first saleable packs will be made in August 2010.  The battery lab is working to develop and refine the processes by which mass production of large numbers of packs is flawless.

Over 50,000 cells have been tested on over 300,000 simulated miles in the lab and to date not a singe cell failure has occurred.

Stress Testing
Cells are exposed to crush, penetration, thermal stress and overcharging.  Modules and packs have been exposed to crush, pressure, shirt circuit,corrosion, thermal stress, and seal integrity.  All is well.

Vehicle Stress Testing
Cars have been exposed to the twist ditch, water exposure, potholes, and vibration.  Crash test have shown battery remains safe at 30 MPH head on, as seen in the picture below.

Learnings
Farah admits NVH (noise vibration and harshness) has been “particularly tricky” especially in charge sustaining mode as the car was tweaked to be extremely quiet in electric mode.  Through changes such as increased insulation, specially designed instead of off-the-shelf bushings and new side airflow vents a pleasing experience has been obtained.

Battery chemistry had to be tweaked slightly to achieve longest lifetime, which will be effectively 10 years, though it was noted in temperate climates much longer lifetimes are possible.  Extreme cold and even more so extreme heat degrade the battery life expectancy.

“10 years is the target life, but depending on where you live, you could see significantly more than that,” said Farah. “In more benign conditions — if you do more city driving — and if you are in a more temperate area, the battery would last significantly longer.”

“But even if you live in Phoenix, as long as you charge at night, and you run during the day, your battery will remain happy,” said Wallace.

It has been found that the battery packs are well protected by the car’s structure and cells handle all abuse situations remarkably well.

Though I asked Farah, he still would not release the size of the gas tank claiming we won’t know until just before launch because its still being tweaked.  The gas engine will likely be programmed to circulate once per month even if the driver never uses it.

Farah also wouldn’t disclose the Chevy Volt’s curb weight though states its was “heavier than I would like.”  Efforts are being made to reduce weight of both the car and 400 pound battery pack.

GM has signed off on the final design freeze of the charging equipment, both 120V, 220V and the in-vehicle on-board charger.

Though not confirming dates, Farah implied he is looking forward to beginning work on the higher performance Cadillac Converj, which has unofficially been greenlighted for production.

Below is a video of the Chevy Volt battery pack undergoing serious crush testing:

I had the following discussion with Alex Cattelan who is the Chevy Volt’s chief powertrain engineer. She has a very deep understanding of how the car operates and recently drove in a fleet of integration Volt prototypes through rugged mountains of Knoxville Tennessee.

Do you feel the charge-sustaining (CS mode) experience is now pretty solid and are you pleased with it?
We are definitely pleased with the level of progression we’re at. We are right on track to where we need to be in terms of the next stages of development we need to do to meet our target. Is it commercial right now, no, but that’s why were taking the time to get it to be commercial. Does it have the capability of being commercial, absolutely. We’ve proven that to ourselves.

We just took our leadership through a test drive in Warren (Michigan) and comments are that they cant tell when the engine is coming on or off. Those are the kind of things we like to hear.

You drove the IVs around the mountains of Tennessee. What about those big hills and the generator. It sounded like it drove very briskly powerfully and effortless is that true?
Yes, absolutely. Some of our control capability to utilize the battery, the engine, and the motors and to be able to optimize for high load and low load situations we’ve been working on developing that stuff for the last year and half an I couldn’t tell you how happy I was when I was in Knoxville because that’s when I had the opportunity to see it all come together. A lot of those bits of software all came together on one trip and it was a joy to drive.

So you took it up some steep hills and mountains?
Absolutely. We were in the Cherokee area taking it up through those hills and a lot of situations following it. It was a very touristy area. Following the speed of traffic, absolutely no problem, and where I had opportunities I certainly like to push the limits of the vehicle, and we did on those mountains, and I could not get it to degrade in performance.

That’s in charge sustaining mode?
Certainly in charge depleting, we have no issues because we have battery power, I’ve got it all at my fingertips. Now in charge sustaining we know that the engine power is slightly less than the peak vehicle power but we have controls ways to manage that and to utilize the engine in conjunction with the battery to get a little bit of extra power when we need it, and replenish it back when we don’t.

I know the battery runs down to roughly the 30% level before for the engine comes on. Is that 30% itself the whole potential buffer band?
We certainly don’t utilize the full 30% but there’s a portion of that that we utilize as a buffer.

You wouldn’t go to zero ever?
No. When the engine cannot meet peak load requirements we’ll suck a little bit out of that buffer and as soon as we have a situation when we can, we’ll put it right back in. All the controls that we work do that to optimize not only the driveability but the efficiency as we’re doing it, NVH (noise vibration harshness) as we’re doing it, the total driving experience as well as to protect the battery from a life experience. This is what allows us to give really good warranty life on our batteries as we’re doing I all in a controlled fashion.

NEW: Discuss this story in the GM-Volt Forum

As some readers may know, I am one of 100 people in New York who are leasing the MINI E electric car for one year.  I recently passed 5000 miles of driving the car, and for the most part am very happy with it, especially in that all those miles have been covered without using one drop of gasoline.

As the car is technically a mule or prototype, it is not production-ready and has had some issues.  A month or two ago it began popping loudly into neutral whenever the accelerator was floored.  The power electronics control unit was replaced and after that it  almost never happened (it happened one more time). So I’m gentle with the accelerator.

The other day I was driving to work and went over an unexpected construction zone pothole.  The car was jostled and suddenly it went into neutral.  After that it could no longer be put into drive.  Despite turning it on and off and moving the shifter in and out of drive neutral and park several times, that was it, dead.  A tow truck was called and off it went to the dealership for a MINI “flying doctor” to come and repair it. After a few days I found out it was the power electronics control unit again which was again replaced.

This made me immediately realize the importance of extensive testing of new electric cars over rough road conditions, potholes and the like.  With new technology electric cars there may be cables that can simply come out stopping the car dead in its tracks.  Fickle electrical connections andsensitive electronics may be more vulnerable to these effects than mechanical combustion powertrains which have been road-tested for a hundred years.

I reached out to Volt vehicle line director Tony Posawatz to see how carefully GM was evaluating pothole effects on the Volt prototypes.

He responded graciously:

We do more tests to our cars and especially the Chevy VOLT than anyone could imagine including some pretty severe potholes on our Milford Provings Grounds and other very difficult road surfaces. As you know, the car quite easily navigated up and down Pikes Peak, through the hills of West Virginia as well as Death Valley during the hottest part of the summer (it was 118 degrees when I called once to check on the team).

So although there may be a lot of new electric car startups on the horizon, the Volt may well have as another advantage GM’s long heritage of specialized quality control testing facilities and expertise.  As has been said before, they must get this one perfect.

An astute observer noticed none other than a pre-production Chevy Volt integration vehicle nonchalantly parked in a neighbor’s driveway.

A fleet of eight of these vehicles just returned from a 3-day 1200-mile extended test drive last week, and perhaps one of the lucky participants got to take one home for the weekend. It is known that 80 of these cars are in existence and nvolced in continuous and extensive testing

General Motors engineers are often given the opportunity to take home pre-production vehicles prior to launch.  In fact, some of the learning that goes into the refinement of these vehicles is derived from these take-home experiences.

However, these IVer Volts are unusually early in development for this type of endeavor.  Most pre-production cars are taken home just a few months prior to launch when they are usually at a high level of refinement. The fact that they are already allowed home appears to confirms the great confidence GM has with their robustness and the particularly advanced level of development they have already achieved in such a short time.

No, its not my house.

Apparently this is nothing new. According to GM spokesperson Rob Peterson, “several engineers have already taken these vehicles home over weekends.”

Source (Autoblog)

On Tuesday morning, eight Chevy Volt integration vehicles left the Milford Proving grounds compound in Michigan on a historic extended test drive into Pittsburgh, Pennsylvania.

The cars were driven for more than 9  hours and 300 miles continuously in a special effort to analyze their behavior, performance, and comfort on such a long drive in real word conditions.

Key personal in attendance on the drive included Volt chief engineer Andrew Farah, Volt vehicle line engineer Tony Posawatz, and advanced technology engineer Larry Nitz.

“Development drives are key milestones for every vehicle program,” said GM spokesperson Rob Peterson. “The extended seat time allows the engineers to experience every aspect of the vehicle – from ride, handling and performance to the comfort of seats. The drives also help uncover engineering issues that need to be resolved before the vehicles are put into the hands of customers.”

“Having the capability to drive several 100 miles in a day is a significant advantage for the Volt team too,” said Peterson. “Remember, the EV1 team needed to be trailered to areas like Pikes Peak or Pennsylvania for testing, or trailer a small generator to extend the vehicle’s range.”

Lead engineer Andrew Farah wrote the following observations about the drive:

HVAC comfort is good, and sound quality in the NVH (noise, vibration, handling) vehicle is excellent.

We have uncovered a number of minor issues with some of the gauges and displays. Up-level sound system makes XM really sound great!

City traffic in Pittsburgh was just what we were looking for after the rolling grades outside of town. On the way in, we all put the transmission selector into the “L” position and this worked as intended in the stop-n-go conditions. At speeds under 35 mph, you can basically drive with one foot because of the heavier regenerative drag as you fully release the accelerator. It is smooth and blended. Seat comfort evaluations are also being conducted. We have our top 3 comfort configurations from previous activities. So far, the top choice seems to be clear, but there is still some work to do.

This was the longest continuous real world drive to date the Volt development vehicles undertook in a single outing, and illustrates how the Volt is capable of doing what no pure battery EV could do.

Besides providing the engineer with valuable data on how to make the cars as perfect as possible, it also produced some very cool photo ops.

Meanwhile GM also announced it was investing over $200 million to upgrade several production facilities in preparation for building the Chevy Volt and Cruze.  In particular, the engine plant in Flint where the 1.4 L Volt engine-generator and 1.4 L turbocharge Cruze engine will be made was allocated $202 million.

GM has just about finished production of 80 integration-vehicle version Chevy Volts. These are full production intent cars that are being used for extensive road testing to generate learning engineers can use to further refine the vehicle for production.

Part of that learning involves putting the car through rigorous real-world driving conditions. We have already heard the cars have performed well in the mountains of Tennessee and the heat of Death Valley.

A very storied and symbolic place to drive is Pike’s Peak. A GM engineer by the name of John Blanchard has written about and confirmed the Chevy Volt has climbed the peak.

This location is interesting because it is 14,115 feet high and has a 19 mile road going up to the summit. It represents the scenario of the car being in generator mode and requiring continuous sustained energy to climb the very long steep grade.

Blanchard confirmed “the Volt was in extended-range mode for the most part of this segment.” On the uphill portion the team was “making sure the Volt could climb the steep inclines and operate at a high altitude.”

As the picture shows, Volt made it to the top, and “climbed the mountain faster than we anticipated,” he wrote. How fast you say? Blanchard didn’t.

The team also evaluated the Volt’s downhill performance too which interestingly represents a long and continuous opportunity to regenerate energy.

“The regenerative feature produced a good amount of energy back into the battery,” said Blanchard. “We were also pleasantly surprised with the temperature of our brakes.”

Back in the summer of 2008 I speculated with the Volt’s chief engineer Andrew Farah whether the Volt (which didn’t exist then) would be limited in speed to due power limitations on Pike’s Peak.

He had said “it’s a problem if you want to do it at 90 mph, but it’s not a problem to get you to the top.”

“There are limitations to the E-REV concept,” he said. “But the people who will experience a problem with this are far and few between.”

It is great news to see that the day the Volt actually did climb Pike’s Peak has really arrived.

Source (GM)