Denise Gray
I just completed two days of discussion with key Chevy Volt executives and brought with me the list of the questions you asked right here. Since at the time of the meetings, there were more than 250 questions, I had to boil them down a little. I got to spend a couple of hours with Tony Posawatz, Volt Vehicle Line Director, and Denise Gray, Battery Chief along with Rob Peterson and Scott Fosgard of GM public relations. Due to the sheer volume of questions, we couldn’t get to them all initially but did eventually get to most; I will break the answers up over a few posts. So check in daily for them all.
First, I wanted to share with you firsthand information about the very first Chevy Volt lithium-ion battery pack which is now sitting in GMs advanced battery lab in Detroit.
The pack is from LG Chem and Compact Power Inc. Denise also mentioned that the pack has fully integrated electronic control systems as well as a functioning liquid cooling system (contrary to prior reports). She relayed the delivery event, on Halloween, and complete with CPI engineers in hand as analogous to a new baby coming into the home..very exciting with many GM employees (excited neighbors) coming around to gawk at it and wish it well.
She relays that the pack is 200 kg, T-shaped, and about 6 feet long, 3 feet wide, and 1-1/2 feet high. These were roughly the dimensions of the table we sat at for lunch which she said happened to be about its size.
She mentioned that the pack is currently undergoing bench testing and has yet to be placed into a mule, but will soon. Furthermore another pack is on its way within 2 weeks, and two more from A123 will arrive after that.
We went over the battery development process and the fact that the initial field of battery contenders were 27, which got cut to 13, and finally to the current two: CPI/LG and A123/Continental. She is in constant contact with the people at both battery companies.
She also defended GM’s decision not to make the batteries in house, as Toyota claims they are, because it makes more sense to work as a group with companies that are excellent at the components they make as opposed to try to do it all themselves.
The pack they got meets all of GM set requirements and is indeed a fully operational 16 kwh pack. Denise tells me special precautions have to be made for the technicians considering the high voltage in regards to their safety. Every cell is monitorable in temperature and voltage with extensive sensing devices.
The cells are segregated into groups or modules each module has a central monitor that evaluated each of its cells, and all the module monitors feed back into a central monitor. All the cells; both from CPI/LG and A123 are prismatic or pancake-shaped (no cylinders). This shape is very important to keep the pack as dense and same as possible, and for better heat dispersion. The modular structure is considered very important from a production, serviceability, and control standpoint.
Indeed there will be several configurations of prototype packs from each manufacturer. Denise’s lab will test them fully on the bench and in mules to see what eventual design will be superior.
No pictures of the pack yet, but I’m working on it.
This entry was posted on Friday, November 16th, 2007 at 8:15 am and is filed under Battery, General. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
Nov 16th, 2007 (8:43 am)That seems pretty big for 16kwh. I wonder if they’ll be able to shrink it or something. One and a half feet seems a bit thick too. Maybe if they could stretch it out to eight feet they could slim it down. Guess we’ll have to wait and see.
Thanks for all this detail.
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Nov 16th, 2007 (9:05 am)Yeah, 1-1/2 feet high?! How would that fit without becoming one heck of an armrest?
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Nov 16th, 2007 (9:20 am)440 lbs! About the same as a normal cars engine i guess.
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Nov 16th, 2007 (9:35 am)I guess that might be a reason the Volt seats 4, not 5. I hope they are telling you about the mules being tested with both types of batteries soon! I wonder what having that much weight down low on a car that ‘only’ weighs 3500 pounds will feel like when you are cornering. The more I think about it, the more I hope that the next E-Flex vehicle will be either an SUV or a pickup, they will tolerate the largeish battery more easily than, say, a Malibu, and improving the gas mileage on the worst mileage cars is much more important than improving mileage on cars that already get decent mileage.
This is a gorgeous car, and its final iteration will probably be nearly as good looking, but the important thing is that we need to stop buying foreign oil. It would be great to go nuclear and/or use more solar and wind, but we HAVE to use less oil.
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Nov 16th, 2007 (10:02 am)Do we have any idea where in the car the battery will be located? With it so big and so heavy, it would seem that options are limited.
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Nov 16th, 2007 (10:04 am)Bob Lutz himself told us they didnt receive cooling system fitted to the LG battery back but
Denise says they have everything inlcluding cooling. Can the information from a company head and battery head differ that much ? Something fishy…
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Nov 16th, 2007 (10:27 am)They should go with Nanosafe by Altair Nano. It doesn’t need a cooling system and is better.
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Nov 16th, 2007 (10:40 am)The A123 batteries are prismatic??? Everything they have built to date has been cylindrical. Including an “automotive prototype” cell taht was shown in an image some time ago. This is somewhat of a aurprise.
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Nov 16th, 2007 (11:02 am)[quote comment="14937"]That seems pretty big for 16kwh. I wonder if they’ll be able to shrink it or something.[/quote]
Remember she said it was T-shapes. I believe the 3 feet wide statemet is the longest length of the “T”. I did some calculations and if you stacked existing A123 cells into a 18KWh battery pack they would crate a space about 20cm x 20cm x 2Meters. There must be a lot of space for cooling.
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Nov 16th, 2007 (11:04 am)[quote]
Remember she said it was T-shapes. I believe the 3 feet wide statemet is the longest length of the “T”.[/quote]
I meant the top width of the “T”.
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Nov 16th, 2007 (11:15 am)Ziv, #4:
I think that the first priority has to be to create a car with fantastic mileage which trumps whatever Toyota and Honda are about to do.
As the price of fuel continues to increase, sales will shift more and more in this direction, and away from SUVs and pickups. Soon enough, it will be as it was in the past. Trucks and “SUVs” will revert to their past roles as utilitarian working vehicles for those who actually need them, and away from being fashion statements. It is happening before our eyes, every day.
The most important thing, both symbolically and from a business point of view, is to reclaim top mileage bragging rights, and the technology high ground, from Toyota and Honda.
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Nov 16th, 2007 (11:59 am)Noel, you make a compelling arguement and I have to admit I would like to gain the ‘bragging rights’ for an American firm, but getting a cars mileage to improve from 30 mpg to 150 only saves 400 gallons of gas a year. If you improve an SUV’s mileage from 15 to 100, you save 850 gallons a year, if you drive 15,000 miles a year. Most people are going to use some gas even with the EFlex system, but I still think that real savings are more important than bragging rights. Symbols are important, but a sharp reduction in the amount of oil we import would change the world. The EFlex system, given time and enough models in production, could do just that.
But I would still like to get a top-mileage econo car with Volt’s muscular style, tho.
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Nov 16th, 2007 (12:03 pm)Scott #8
I’m fairly surprised that the cells are prismatic as well.
I just spoke with the Director of Vehicle Development at Magna Steyr on Tuesday and the Hyrid Vehicle Lithuim Ion battery pack they’re soon to be coming out with will be using A123’s cylindrical Li-ion cells.
???? Maybe A123 is making something special for the General and the Volt.
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Nov 16th, 2007 (12:21 pm)This is great information. Can’t wait to hear what the others at GM had to say. Also, Lyle yes do try to get a picture of the battery pack if possible.
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Nov 16th, 2007 (1:39 pm)I wouldn’t try to second guess the engineering team about which configuration of battery is best (e.g. Nanosafe by Altair Nano, or cylindric or not). That’s their job, and I’m sure that they have put a lot of effort into making the best compromise.
I suspect that the T shape is destined to have the cross of the T under the rear seat, and the down stroke of the T in the tunnel.
200Kg of weight centrally located low like that wow! That gives new meaning to being a “mid engine” car.
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Nov 16th, 2007 (2:12 pm)Although I’ve heard rumors about prismatic A123’s before, it still surprises me a lot, considering that their automotive cells are basically just their power tool 26650’s with a bigger diameter.
What she said about prismatic cells in general makes sense because they can be stacked into packs with greater volumetric efficiency than cylinders (gaps of space in between cylinders). However, the prismatics tend to have poorer energy density, which means a weight and energy/volume penalty anyway. So I’m not sure it’ll be worth it.
In all honesty, the A123-based KillaCycle pack (which I’ve had the opportunity to examine in the flesh/metal) seems like it would be a better starting point, since it holds 9.1kWh and is only 2 cubic feet. Running cooling lines through the gaps between the cylinders shouldn’t be that hard, actually.
A weight of 200 KILOGRAMS also seems consistent with white papers indicating CPI’s energy density is around 95Wh/kg or less.
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Nov 16th, 2007 (2:24 pm)PM #7-
AltairNano’s cells hold around 79Wh/kg without any of the packaging or control electronics. At 16kWh and 200kg, that’s a gross energy density of around 80 for the entire CPI pack.
The cooling is necessary to extend calendar life of any lithium ion pack – any high power system is going to develop heat.
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Nov 16th, 2007 (2:40 pm)I have always performed minor maintenance on my vehicles (oil changes, transmition fluid changes, replacing batteries, etc.). I assume it will not be a good idea to tinker with the Volt due to the risk of being shocked.
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Nov 16th, 2007 (2:59 pm)ziv #12:
If we were to focus on improving the fuel economy of the SUV’s and Trucks to save more fuel, this would create an incentive for consumers to keep purchasing large vehicles that are usually hauling around 1 person. We need to change their midset. Unfortunately, in the US, there is only one way to to that. Show them thefinancial incentive. If SUV owners are spending $100+ to fuel their vehicle, and their neighbor hasn’t been to the gas station in months…..they may change their lifestyle to help their wallet if not for the environment.
Either way….bring on the Volt! I’m buying one and trading in my 42mpg Jetta TDI.
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Nov 16th, 2007 (4:12 pm)Some evidence that the A123 cells may indeed be prismatic:
http://www.greencarcongress.com/2007/08/gm-and-a123syst.html
“The contract calls for A123Systems to develop battery cells to meet the specific requirements of GM’s E-Flex system.”
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Nov 16th, 2007 (4:13 pm)Adopting the chemistry to a new cell format would also explain the delay in delivering the pack to GM.
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Nov 16th, 2007 (5:31 pm)My despair over the switch to non-cylindrical is short-lived, however. Lithium iron phosphate prismatic/polymer cells aren’t necessarily low, low energy:
http://www.phet.com.tw/Products/Cell_Spec03.aspx
125Wh/kg
That’s an official Phostech-licensed cell as well – if A123 can get their cells to be similar to that, and with better power density that’s inherent to the A123 formulation, then my bet is on them to deliver the better battery for the Volt.
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Nov 16th, 2007 (5:36 pm)ziv, #12:
Check out Mr. Lutz’s comments in the US News article linked to the post directly above.
Your points are well taken. God send that this and subsequent technology dramatically raises the mileage of the whole fleet – the sooner the better.
I am just saying that retaking technology leadership is Job #1. I may be taking too much upon myself, but I think that Mr. Lutz is saying the same thing. If so, it is the best, and most encouraging, thing I have heard from him in several months of carefully following this and the Fastlane blogs.
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Nov 16th, 2007 (9:04 pm)The Altair nanosafes fail to provide the voltage (the power) – remember A123 Systems’ director saying their batteries produced TWICE the power of the Altair’s. Altairs are also way too expensive – they only have a chance in an $80,000 car and have lost out on those contracts to a Chinese company. That same A123 Systems exec claimed his batteries will get to around $250 per kwatthour in a few years, while NanoSafes are today over $1000 and have little chance of ever getting to $500. No automaker has expressed any interest in Altair batteries for either a plug-in or a battery-powered EV. If GM did, they would be the first. I’m sure GM is well aware of the capabilities of the Altair batteries without any assistence from Altair shareholders. Right now, BYD’s batteries appear to be the most practical,
although they are not as powerful as either type being considered by GM.
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Nov 16th, 2007 (9:15 pm)I still have the feeling that both battery
companies will be given a production contract, probably one for the Flextreme (and its siblings) and one for the VOLT (and its siblings). I assume the two pack configurations reflect the two distinct chassis requirements. I’m assuming a Saturn
E-Flex ala the Flextreme and a Pontiac on the VOLT’s chassis. I also assume that each
E-flex will have only one type of battery.
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Nov 16th, 2007 (10:47 pm)Kent,
I thought those two were on the same Delta II platform, but its hard to keep up with the game.
Maybe one is for the Epsilon platform, Malibu, Aura,Vectra?
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Nov 17th, 2007 (12:41 am)I’m sure it duplicates some info already on this site, but I’m not sure…
http://www.engineeringnews.co.za/article.php?a_id=120578
at the end, about the batteries mentions:
“John Smith, group vice-president for GM North America Vehicle Sales, said that the goal is to improve the batteries so that they can be used to a 20% state of charge, which would increase the electric-only mileage potential. The durability goal is 4,000 recharging cycles, which would be good for ten years.”
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Nov 17th, 2007 (4:08 am)what I’m curious about is this: if the battery for the Volt weighs 200kg for a 40 mile range, does that mean that a battery for a 100 mile range (like this for the pure electric car) would weigh 500kg? where will there be place in the car for such a gigantic battery? especially when refering to the Better PLC project, who has this idea to swap batteries in 3 minutes… am I the only one who thinks it’s an undoable idea?
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Nov 17th, 2007 (7:25 am)“The Altair nanosafes fail to provide the voltage (the power) – remember A123 Systems’ director saying their batteries produced TWICE the power of the Altair’s.”
Q: What is the voltage of your modules and the 35kWh packs?
A: 12V and 420V respectively.
“No automaker has expressed any interest in Altair batteries for either a plug-in or a battery-powered EV.”
http://www.lightningcarcompany.com/nanosafe.php
http://www.phoenixmotorcars.com/partners/index.html
http://digiads.com.au/car-news/latest-FIAT-news/2007_AllElectric_Fiat_Doblo_300km_Journey_200710.html
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Nov 17th, 2007 (10:23 am)Altair right now is a great battery but they are a boutique operation. They have great intellectual property but no big production facility, no sub in place to do it cheaply for them. They had been in talks with GBT but those allegedly broke down and now GBT is working with a Chinese auto company, Lam of Lotus fame, and Zap of California to market cars and their stationary batteries in America. Now that CBAK has broke off with A123 one has to speculate that ALTI and CBAK could be talking … but even if they partner they are too late for GM.
Their current product is best suited for some particular niches. An expensive high capacity (much more energy dense although not as power dense than A123’s) rapid recharge capable battery (if you have the recharge station) – perfect for high mileage fleet vehicles with access to the charging station once a shift and whose high mileage garners enough gas savings to more than offset the battery cost within a few years – a big niche really (think everything from taxis to police cars to all those package delivery and other delivery trucks to buses and garbage trucks), but not one that includes the Volt.
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Nov 17th, 2007 (2:51 pm)Altair has an exclusivity agreement with Phoenix Motorcars for North America so they couldn’t supply GM easily anyway.
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Nov 30th, 2007 (7:59 am)Hopefully the one and a half foot high pack is actually only a one half foot high pack.
Hopefully the prismatic cells from A123/GM have already been developed and shipped to Continental AG where they are being packaged with controls and cooling if necessary, for shipment to GM before the end of the year.
Hopefully the cost per KWH for these A123/GM batteries will be less than $750.
If so, America may actually do something to end its dependence on foreign oil. Time will tell
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