- Posted on Wednesday, March 14th, 2007 at 3:00 pm
A Closer Look at Batteries
By Denise Gray
Director, Hybrid Energy Storage Systems
As you may know from reading Beth Lowery’s post on FastLane, we held a briefing Monday here in Detroit on the battery requirements for powering GM’s range of hybrid and electric vehicles. I wanted to take this opportunity to talk a little more about the batteries themselves, and what GM requires for these advanced technology vehicles.
For GM’s different vehicles, the battery requirements vary. For instance, the battery in the upcoming Chevrolet Tahoe two-mode hybrid has to supply electric vehicle operation at low speeds, recharge only while driving, and be designed for very limited electric-only drive. In the Saturn VUE two-mode plug-in hybrid (PHEV), the battery needs to provide more than 10 miles of all electric drive, charge while driving and when plugged in, and provide full electric drive at low speeds.
And for an E-Flex range extended electric vehicle like the Chevrolet Volt, the battery will have to provide at least 40 miles in the city and be charged while driving through regenerative braking and also by being plugged in. In simplistic terms, the Tahoe’s power battery is much like that of a sprinter — it needs to provide small bursts of energy, while the battery for the Saturn VUE PHEV and the Volt is more like that of a marathoner — it needs to provide constant energy.
To meet the requirements for these new demanding vehicle applications, their batteries have to offer a range of power and energy density in smaller packages and therefore are more challenging than the nickel metal hydride (NiMH) batteries on the road today. Enter lithium ion batteries, which are becoming the leading contenders to power future hybrid or electric powered vehicles. Lithium ion represents an improvement over NiMH because it provides higher energy — the type needed for the Volt, in a smaller and lighter battery pack (compared to a NiMH battery, a Li-ion battery can produce the same amount of energy in a package at 40 percent the volume and 20 percent of the mass).
We have very smart partners working on advanced batteries, and I believe that it will take evolutionary, and not revolutionary, advances to tackle these battery-related challenges and make these vehicles a reality in the not-too-distant future. Of course, we face the added challenge of developing the battery solutions and the new vehicles at the same time, but that’s a subject for another post!
3 Comments
Dale
It’s good to hear you are looking into developing more electric cars.
I have always thought it would be good to fit electric cars with a solar panel on the roof so the car can be recharged (at least partially) while driving.
I hope you will consider making these cars available in Australia because currently, we don’t have any 100% electric cars available - only a handful of hybrids.
storm connors
What is the magic about 40 miles for the Volt? If it could go 10 miles on battery power range would not be a problem because of the onboard recharge capability. The latest noise from GM is that the batteries have to last for some currently unobtainable length of time as well. Would a $20,000 pack that lasted for 10 years really be better than a $2,000 pack that had to be replaced every 4 years?
Build the car with current technology instead of building excuses why it can’t be done.
The Volt could be built tomorrow. Use AGM lead acid batteries if you can’t get back the NiMH technology you developed and sold to Mobil. Why GM wants to squander yet another chance to be a leader is inexplicable. A usable Volt today beats a perfect Volt someday.
Nick
Good post,
I agree with the general sentiment of this article, but I want to speak a little on an alternative method that doesn’t get as much attention as it should. Making cars more expendable. Our overeliance on our own personal automobiles is what allows us to be slaves to the gas prices. When gas hits $5.00 a gallon (or more), savings from a different battery will be a drop in the bucket. For those of us who live in big cities or smaller urban areas, why not try using different modes of transportation? If you live, work or shop anywhere on the busline, start using that for a change. If you are only going a short distance and the weather permits, try riding a bike or even walking. If you live in a major metropolitan area, then the subway or a light rail is also another option. I live in a big city and as long as it’s not freezing or raining I usually always walk anywhere within a 10 block radius. If I need to go to the grocery store and don’t want to walk that far with a handful of bags, I’ll take the bus. I ride my bike sometimes as well. If I need to travel farther distances, I do drive, but only when I have to. I have plenty of friends will drive to the store when it’s only 2 and a half blocks a way. They waste gas by needlessly driving everywhere (no matter how close), yet they complain the loudest about spending all their money on gas. Of course, for those that live in the suburbs or rural areas, it may be more difficult. There are other options though. Carpooling, for example, is a great solution that enough people don’t make use of in my opinion. Also if you happen to live in the suburbs or the country, simply making a more efficient use of your driving time would help in terms of gas costs. Try to make all your stops in one trip, and in the shortest route, that way you minimize the time of making trips to and from your house or apartment every single time you need to go out. Plan ahead and make all your trips at once. Gas costs money. New high technology batteries cost money. Hybrid cars costs money etc. But Carpooling can typically cut costs by as much as 4/5ths. A bicycle may cost a couple of hundred dollars up front, but it doesn’t run on fuel. Bus passes are usually dirt cheap. Walking is always free. Try to make use of these when you can! You’ll need to talk to others in your local communities to organize a carpool or get information regarding a bus pass, and walking requires no explanation, but for those thinking of giving a bicycle a try here is a good guide that goes into detail about what to look for when picking out a bicycle. I wouldn’t recommend purchashing a bicyle online — you should probably visit your local bicycle retailer or large department store for a purchase like that. It’s still a good idea to read about some of the differences between bikes and what to know about different speeds, frames, and sizes etc. Anyway, just thought I would pass that along. I enjoyed reading your post though. Very informative. Thanks for sharing and keep up the good work!
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