GM-VOLT : Chevy Volt Electric Car Site

Leftlanenews.com had the chance to interview Bob Lutz and included some Volt talk.

The GM vice-chairman confirmed that the prototype batteries have been tested both in extreme cold and extreme heat conditions, and aside from some solder failures on the prototypes he said that in terms of the lithium-ion chemistry, there has been an “eerie”, “almost scary absence of problems with the battery.”

He noted that one of the major challenges in the vehicle is to write computer code for the “zillions” of possible interactions between the driver, electric drive, battery, and regeneration and when the combustion engine should come on.

With respect to that, he describes an interesting scenario where its 40 below in North Dakota and the battery needs to be warmed in order to function properly. He notes this would be a big challenge for a pure EV, but in the Volt the car would start out with the combustion engine on and “run for a few minutes to warm up the battery so that the battery can take over.”

He also indicates that the OnStar navigation system will know how far the driver is from home and if the car happens to be at the customer depletion point, it could calculate and to provide just enough charge to get the driver home.

Finally Lutz also denied that there have been internal discussions about sharing E-Flex technology with Ford but states it his impression that “the whole worldwide industry is converging around this Volt concept as the intelligent way to go.”

Source (LeftLaneNews)

[NOTE: For those who may be interested I will be appearing on FOX Business News at 7:15-7:30 PM EST tonight 8/27 for a live interview]

Some may have noticed an anonymous “Battery Expert” made an appearance in some of our previous posts’ comments sections. He/she claimed the Volt’s batteries might not survive their lifecycle requirements at different temperatures. It is he/she who created the graphic shown above.

Not being a battery expert myself, and seeking clarification of this issue, I went to my own anonymous source who is indeed a verified PhD lithium-ion automotive battery expert intimately knowledgeable about many of the current automakers projects, including the Volt. He had this to say:

“Battery life will be shortened when exposed to high temperatures… as is the case for all
chemistries including Lead, NiCd, NiMH and Sodium. Initial findings indicate that most Li-Ion
cells should be able to go the distance of 10 years while only losing ~20% of their capacity even
at a steady temperature of 30*C. This is due to normal electrolyte corrosion and breakdown issues.
Most climates and driving habits will keep the cells below the aforementioned 30*C, insuring
good battery life for a vast majority of owners.

Obviously, under more stressful driving and desert climates, the cells may loose more than 20%
of their original capacity in 10 years. The automotive engineers are aware of this and some
“oversizing” is being specified to give consistent performance to the owner of the PHEV/EV. It is
still prudent to keep the car in a garage rather than parking it on a blacktop driveway in the middle
of summer.

All Electric Range or Effective Electric Range can be reduced, particularly in extreme cold
conditions when the Li-ion battery has some difficulty in accepting rapid charge from regen
braking. This is due to the inability of the SEI layer and carbon based anodes to accept the Li
ions, and some degree of Lithium plating occurs… much like in cell phone batteries that are
“quick charged.” Under warmer conditions it is easier for the Li-ion cells to deliver full AER
as the cell’s internal impedance is lower and full power can be delivered or accepted over a wider
range of SOC.

Even after the cells lose 20% capacity, the PHEV/EV is still quite drivable and useful. The AER
may start to reduce, but this is similar to fuel economy degradation in a 100,000 mile used gasoline
powered vehicle.”

Further, this same commenter also claimed Dr. Nazri, an advanced battery scientist at GMs R&D department “does not trust this at all” when it came to battery durability. I contacted Dr. Nazri, and his reply:

“This is absolutely false, and I have not made any comment of this sort. This kind of false fabrication may not help reputation of your organization. I am Volt enthusiast myself.”

It looks like our “Battery Expert” really is fabricating things other than batteries.