Grab our RSS Feed

AND

Are the Volt Prototype Packs Running Too Hot?

January 1st, 2008 | Posted in: Battery, Engineering, General

Recently a commenter here suggested he had inside information about thermal regulation problems with the Volt prototype battery packs. Here is his comment:

My brother in law is an engineer for this product and said there’s NO WAY it will work as designed. The battery will never be perfected, gets way too hot (much like a laptop) and they have NO effective solution for this. Sorry, better have a back up plan.

I tried to contact this person, but they were unavailable for comment. Statements like this are very concerning to us here; we don’t want to spread rumors, but on the other hand we do wish to reveal the truth. I reached out to GM for any comments on this matter.

Here is the GM E-Flex team spokesperson’s official response:

Thermal management is a challenge, but one the E-flex team is confident engineering solutions will overcome. That said, the team has been very pleased with the test results of both CPI batteries. In fact, I spoke with a member of the battery team last week – he was extremely pleased with the results – I haven’t spoken to him since, but I also haven’t seen any e-mail traffic that would indicate there have been any issues. Not sure who the insider is, but his info doesn’t sync with what I know.

Happy New Year to All!

Posted by: Lyle

39 Responses to “Are the Volt Prototype Packs Running Too Hot?”

Rashiid Amul Says:
January 1st, 2008 at 9:35 am

Thanks Lyle. Happy New Year to you and yours.

There is no better way to find out the truth to rumors than to go straight to the horse’s mouth. GM knows the challenges and will hit them head on.

Go Volt Team and Happy New Year!

(Quote)
Dave B Says:
January 1st, 2008 at 9:36 am

Tesla was also said to have had the same overheating issues, however, that clearly isn’t the case. For them, it’s the transmission that seems to be the problem.

I’d think GM’s Volt, with only 40 miles of all EV range would have a simpler solution for the heat problem than Tesla, but I no engineer.

(Quote)
AES Says:
January 1st, 2008 at 10:09 am

The “insider” sounds like an internet troll playing on stereotypes about laptop lithium ion batteries. Nothing more.

That said, I’ve played around with A123 (although not CPI) cells a lot as a part of hobby work, so I can say FIRST HAND that:

1) They don’t explode or violently burn. Period. End of debate about exploding electric cars.

2) Under rapid recharging from a 12V car battery, they’ll go from dead to fully charged in just over 20 minutes (although balancing takes maybe 10 mins longer), and there is a fair beat of heat generated by the power electronics of the charger, but not so much that I couldn’t hold it with bare hands. This wouldn’t be too hard to cool off with a basic heat sink or air cooling, let alone a pro HVAC system. Bigger task with a bigger battery, obviously.

The battery itself got warm (the first in series more than the second), but never hot at all. And that’s under the most thermally intensive circumstance. They’ve never gotten warm under discharge.

(Quote)
Marty McFly Says:
January 1st, 2008 at 10:12 am

I find it hard to believe these battery producers have “no effective solution for this”. More likely scenario is that a cooling system hasn’t been installed or designed for the initial battery sets.

I’m sure there are plans to install a cooling device/panels between the battery plates or even a more simple solution like installing fans, heatsinks, or even a waterjacket.

Not sure about LG but, doesn’t A123’s battery chemistry allow for a reduced thermal variance and the elimination of chain reaction run-away ? Wasn’t that the point of picking A123 in the first place ?

(Quote)
Gary Says:
January 1st, 2008 at 12:02 pm

I doubt the insider has any real information. If, by chance, he does, I don’t think one persons ignorance and lack of imagination will doom the project.

I’m sure there were engineers at NASA in 1968 who thought the obstacles they had to overcome were too difficult to surmount.

Those engineers were pushed aside by the ones who had a set and found a way to do it.

(Quote)
Jim I Says:
January 1st, 2008 at 12:18 pm

This is pretty much new technology, and it is only the first two battery packs. I am sure they will have a few bugs that need to be worked out. By the time these are ready for the production units, they will work to spec.

Happy New Year Everyone!

(Quote)
Dave G Says:
January 1st, 2008 at 12:23 pm

Lyle – thanks for getting putting in the due diligence to get this straight. With many people posting on this forum, there is bound to be some B.S. cropping up. It makes a big difference when that gets put to bed right away. One of the many things that makes this such a great site.

(Quote)
Dave G Says:
January 1st, 2008 at 12:26 pm

[quote comment="23577"]I’m sure there are plans to install a cooling device/panels between the battery plates or even a more simple solution like installing fans, heatsinks, or even a waterjacket.[/quote]

Actually, we know from GM that the battery pack is liquid cooled. Lyle posted this info many months ago. Hope this helps.

(Quote)
VoltZealot Says:
January 1st, 2008 at 12:34 pm

Welcome to the land of out and out trolling. In my book, this was a plant by someone who was paid or has a vested interest in it’s failure. My brother in law says? Nice. I sat up when I saw that comment from an insider vendor saying that Toyota was screaming internally at everyone when switching battery tracks a few months ago. Then Toyota announces this week that they are on a new track to produce Lion batteries. This new comment? The thermal issues will NEVER be solved? Yes, that sounds like an engineer doesn’t it? No, it doesn’t, as they know that solutions happen all the time. This was a troll for disinformation, so they need to provide a bit of detail, or it’s suspect. Period.

(Quote)
Peter Wang Says:
January 1st, 2008 at 12:36 pm

Does water-cooling the batteries make enough heat available to heat the passenger compartment in cold weather?

(Quote)
voltman Says:
January 1st, 2008 at 1:06 pm

Gee whiz. How ever would you get rid of heat? Car engineers have never had to deal with this before! Oh no! /sarcasm

(Quote)
Robert.V Says:
January 1st, 2008 at 1:35 pm

[quote comment="23601"]My brother in law says? Nice. I sat up when I saw that comment from an insider vendor saying that Toyota was screaming internally at everyone when switching battery tracks a few months ago. Then Toyota announces this week that they are on a new track to produce Lion batteries. This new comment? The thermal issues will NEVER be solved? Yes, that sounds like an engineer doesn’t it? Period.[/quote]

I aggree completely! They aren’t going to come this far and throw their hands up because of a heat problem, assuming one even exists.
[quote comment="23610"]Gee whiz. How ever would you get rid of heat? Car engineers have never had to deal with this before! Oh no! /sarcasm[/quote]

I dont know about you guys but my car absorbs heat and blows snow balls out of the tailpipe..

(Quote)
hevfuture Says:
January 1st, 2008 at 1:49 pm

Does anyone know what chemistry refinements LG Chem/CPI is using? I know they are using manganese spinel and an advanced separator, but I am curious as to whether anyone knows of any other chemistry modifications they are using? They claim to have a higher capacity in the second pack they delivered to GM, and I am curious as to how they are achieving that with the same manganese spinel cathode, without a dramatic change in the chemistry of the cathode. This would definitely be a question to ask CPI/LG Chem.

(Quote)
Tagamet Says:
January 1st, 2008 at 1:56 pm

“Thermal management is a challenge, but one the E-flex team is confident engineering solutions will overcome.”

I guess I’m just cursed by the habit of over-parsing, but this does seem to at suggest that there is a heat “challenge”. On the other hand, when I read the “brother-in-law” comment I immediately thought of the “I’m no expert, but I DID sleep at a Holiday Inn Express last night” commercials. Whatever the actual status of the battery packs at this point, there’s plenty of time on the clock to get things right. As much as I’d like to be looking at a Volt in my driveway today, I know it’s more important that GM gets it done right, than getting it done quick(although BOTH would be even better). I guess I’m still worried that the big T will leverage their experience to market something competetive in 2009.

(Quote)
nasaman Says:
January 1st, 2008 at 2:51 pm

The alleged “brother-in-law” is blowing smoke! I have approx 15 yrs of experience with long-life spacecraft/satellite batteries, none of which are accessible for replacement if they fail. The many battery designs I’ve worked on utilize three different chemistries (none of them Li-Ion), but ALL of them become exothermic (give off heat) AFTER they’ve reached a fully-charged state …since the cells can no longer accept charge currents after they’re fully charged, the charging current is converted to heat.

Also, 15/20-yr satellite batteries are FULLY (100%) CHARGED & FULLY DISCHARGED (to 0%) periodically as part of a widely-employed “reconditioning/cell matching” protocol. Individual cells occasionally fail, but complete battery failures are extremely rare …and thermal problems are easily avoided in the satellite’s design. Overheating should not be a problem for GM with their very mild 30%-80% operating protocol.

My guess is that GM’s REAL challenge is to keep battery temperatures from dropping to the very low ambient temperatures of Canadian & Alaskan winters. But that should also be pretty easy & inexpensive to do by use of ordinary insulation, conventional liquid coolants like ethylene glycol & low-power electrical heaters. Nothing exotic is needed.

(Quote)
TheSaint Says:
January 1st, 2008 at 4:17 pm

About cars, all I know is how to drive them and perhaps change the oil and filters. It is comforting to read the comments of guy such as nasaman, and those of you who know for a fact the stuff you are discussing here, and not from “a brother in law.” NASA, they went to the moon and they are the reason why today we are enjoying so many technological breakthroughs. So, when someone from NASA, even if the experience is only in space. I take a seat and listen. There ain’t no mountain high enough, aint’t no valley low enough, ain’t no battery hot or cold enough to keep GM from delivering the Volt to us. For Christ sake, GM invented the automatic transmission, I am sure they can tackle this thermal heat management thing. Happy New Year.

(Quote)
kent beuchert Says:
January 1st, 2008 at 4:21 pm

My experience with “inside information” is that almost universally it is an attempt by
the provider to get attention, usually, as here, by relating some “disturbing or astonishing ” event.
Look at this from our knowledge base – there has been no problem over the past 100 years in cooling giant gasoline engines, that have the ability to emit the enormous
amount of heat generated in the process of burning gasoline through controlled explosions. Now this fellow expects me to swallow the idea that the warmth generated by a battery pack cannot be handled?? I’m not quite that gullible. So this joker is claiming that all those engineers have searched for the past few short weeks to find a “solution” and have all come to the conclusion that a solution is impossible?
How about some truth in advertising and
having this joker provide a detailed explanation of exactly how he has arrived at his conclusion? I don’t care about his name – I want to hear his explanation, chapter and verse. This should be fun.

(Quote)
Mark H. Says:
January 1st, 2008 at 4:22 pm

This is an interesting thread. I was doing some reading about the EV1 and the Nimh batteries. Another comment where I was reading is that the EV1 with Nimh Batteries would explode under high heat and high load. I thought GM’s problems with the batteries were just limited to the early Pb batteries. can anyone confirm that the Nimh batteries used in the EV1 did fail as was said ? Sorry I was all over the net and can’t remember the site. From what I have gleamed from reading this site is that Toyota’s Nimh packs are still kicking. This thermal issue does not seems too hard especialy if there is a radiator in the car, GM could use a radiator with an automatic transmision cooler to cool the pack or warm it. Seems like an easy do.

(Quote)
nasaman Says:
January 1st, 2008 at 5:58 pm

Mark H. #18 – There are thousands of long-life communications satellites in orbit with NiMH batteries operating for 10+ yrs without thermal problems (although the temperature range outside the satellite can be on the order of -300 to +300 deg!) To my knowledge, NONE of these satellites use any thermal control measures other than insulation, thermal radiators, electrical heaters and thermostats. Adding liquid cooling/heating to the Volt battery pack gives GM a LOT of control margin, especially since the terrestrial temperature range is less than 1/3 that in space.

So it’s a fairly routine design problem in thermodynamics, probably not much harder than cooling an automatic transmission, as you say, or warming a V8 engine block in sub-zero temperatures. My physics prof would say simply, “QED!”

PS: I haven’t read anything about NiMH thermal or load problems in later model EV-1s, but if they had any problems it was only because GM got hasty and cut some corners, not because of anything fundamental to NiMH battery chemistry. And you can be assured GM won’t cut corners on the VOLT!!!

(Quote)
Firefly Says:
January 1st, 2008 at 6:32 pm

I was watching an episode of “the Bernie Mac show” where he had to add a new bedroom onto his home for his neice. His contractor said that in his line of work, he followed a “builder’s triangle”. On one side was the word “good”, on another side “fast” and on the third side, “cheap”. HIs analogy was this:

1)Good + Cheap = won’t be fast
2)Good + Fast = won’t be cheap
3)Cheap + Fast = won’t be good

With any new man-made technology, there are invariably bugs to be found and worked out. As someone pointed out earlier with the NASA example. GM obviously has a lot of vested interest in this technology, not just the vehicle. To introduce something of this level, and consequently generate an enthusiast following as it has, I do not believe that they would be stumped and give up over a heating issue. It’s just another conundrum to be solved. At one point in our history, man would never go into space, let alone set foot on the moon, nor did we think 1000 horsepower on a passenger car was possible. I think this is merely a developmental hiccup that was inevitable, but that should not cause one to believe the end is near. There are ways to cool it off from air cooling to heat sinking. After all, every time I look at the E-Flex chassis pictures, I am reminded that cooling will always be an issue, considering that there is a radiator in front. Forced induction cars use various types of intercoolers and heat exchangers. This, coupled with an effective venturi design to channel cooler air towards the battery and expel the heat in the most efficient way possible to do this. I’m no engineer and I figured this out, so I’m more than certain that GM was months ahead of me. As for the contradictory rumor that has been in circulation, I wouldn’t too much worry about that. Many americans have lost faith in domestic products, but I have to remind them that most if not all of the japanese “brand” cars were built in america, by americans, using american made tooling, to create american based parts from american sourced material. Technically, the Camry, Accord, and a crapload of others are in essence ‘domestic’. Volt lovers? I wouldn’t worry if I were you. Take pride in the fact that you are open minded and intelligent enough to thoroughly evaluate new possibilities rather than shun them in ignorance. I consider myself honored to post among intellectuals…

Happy New Year to all of you.

(Quote)
Dave G Says:
January 1st, 2008 at 8:11 pm

[quote comment="23666"]
1)Good + Cheap = won’t be fast
2)Good + Fast = won’t be cheap
3)Cheap + Fast = won’t be good
[/quote]

I also heard this at work about 15 years ago. I believed it then, but my personal experience since then hasn’t lined up with this. Many of the projects that were designed the fastest turned out to be the best quality.

Spcifically, if you get a project that has very definate focused goals, and you get management that can make good decisions quickly, then designers tend to get in the “zone” and get way more creative and productive.

Of course, if management tries to rush things too much, then people get demotivated and quality goes down the toilet. But if developers buy into schedules that are focused and realistic, good things can happen fast. I’ve seen this a lot.

Let’s hope the Volt development team is in this “zone”.

(Quote)
Tagamet Says:
January 1st, 2008 at 8:23 pm

“Let’s hope the Volt development team is in this “zone”.”

From your lips to God’s ears….

(Quote)
GXT Says:
January 1st, 2008 at 8:45 pm

#20:

I think that is a bit of a misquote of the Project Management triangle of balancing Scope, Cost, and Time. Quality (i.e. “good”) is another issue.

Re the original post:
GM indicates that they are having thermal challenges that require solutions. I am just as sure that they would not tell us the full scope of the issues as I am sure that they are trying to address them.

However this is primarily a PR project that is leaning on engineering. Whether engineering will find a solution in a reasonable time frame is still undetermined.

If this were easy everyone would be doing it.

(Quote)
AES Says:
January 1st, 2008 at 10:15 pm

I will echo many posters here by saying that if automotive engineers can successfully and efficiently cool an internal combustion engine, then cooling a battery pack should be an evolutionary step, rather than the revolutionary step that detractors (e.g. brothers-in-law)constantly imply.

Getting HVAC systems running at the best possible efficiency, rather than running PERIOD, is probably what the eflex team is working on right now.

(Quote)
Demetrius Says:
January 1st, 2008 at 10:47 pm

I am in IT and I know one thing about computer projects that may be relevant. KISS.

GM over engineered the EV1. It cost 1 billion dollars in development and the engineers built a complex (yet elegant) system. Since they killed it because it cost so much (and therefore nobody wanted them.?..), they could just have created a simpler retrofit like Toyota and Ford did. The final result was the same.

If electric cars are to have less maintenance than ICE, they better be simpler in design.

I think this would help the Volt because the engineers wouldn’t have to work out all the complex issues with Volt 1.0 that may become easily solved in 2.0 when vastly better batteries appear in 5 years.

(Quote)
mmcc Says:
January 2nd, 2008 at 12:54 am

This topic brings up a concern I’ve had with garage temperatures in the summer. Even here in S Idaho we get some 100+ days in the summer and the garage can get quite warm. If there is some sort of supplemental cooling on the battery pack during charging, this heat will be transferred to the enclosed garage environment and at some point it could reach a point at which the battery cooling system would cease to perform as designed. Are my concerns valid or am I missing something on the battery/thermal issue?

(Quote)
Van Says:
January 2nd, 2008 at 8:45 am

Yes, if you enclose the Volt such that the outside air temperature exceeds the design envelop, it will get too hot. But this is unlikely because heat will leak out your garage. If the thermal leakage is too low, you might need to open the garage door a tad.

For reasons I do not understand, a subset of internet posters, lets call them trolls, like to post positions contrary to any view being asserted. But remarkably, nearly all the posters that frequent this website offer what they believe is true, sometimes in support, sometimes with a correction. Just one of the reasons this is a great site.

Happy New Year

(Quote)
ryfxor Says:
January 2nd, 2008 at 1:02 pm

Well, the simple fact that GM chose liquid cooling instead of air cooling means that there ARE thermal managment issues. Certainly not impossible to overcome though. The problem lies in the fact that LiFePO4 chemistry doesn’t like at all overheating above around 60°C. Heat dissipation is proportionnal to the temperature difference.And unlike internal combustion engine, where the air you use is 20°C when the engine is above 500, for the battery you get a tiny 2 digit difference (40-20 for instance).

(Quote)
noel park Says:
January 2nd, 2008 at 1:37 pm

Reference Dave G, #8:

When it was mentioned here that the batteries were to be water cooled, I thought it seemed like total overkill. I mean, why not just blow some cool air over them a la race car brakes?

Since it seems to have been decided to water cool them, then it would seem, as so many of you have already pointed out, that this is a non-problem. Can anyone say “bigger radiator”? As horsepower goes up in race cars, the cooling systems are dialed up to match. As nasaman mught say, “It’s not rocket science.”

(Quote)
Jeff M Says:
January 2nd, 2008 at 1:37 pm

I’m really surprised Lyle started a new thread based on an obscure comment. That unsubstantiated comment would have simply been lost and fogotten… now you’ve givent that person exactly what they wanted… attention… and may now encourage others

(Quote)
Firefly Says:
January 2nd, 2008 at 4:11 pm

to Dave G:

I appreciate your input on my interpretation. I had not examined it from the standpoint that you pointed out. Thank you for giving me another level to think on. I try to be as concise with my comments, but sometimes having someone broaden your look on things is a welcome transition. I respect your interpretation and thank you. Like I said, I enjoy intellectual conversation. I hope one day when the Volt comes out and we purchase one, they’ll be a Volt owners conference. Then I can meet a lot of you and I guess we’ll share engineering “war stories”, if you will.

(Quote)
AES Says:
January 2nd, 2008 at 5:16 pm

I once parked my car in the middle of the hot Mojave desert sun in summer with my metal Powerbook in the trunk/boot. I came back 48 hours later, and the laptop was still cool to the touch. It probably helped that the car was black, but the point is that the biggest heat threat to the batteries is probably themselves rather than the environment.

Warming them up in winter might be a different issue. That’s why I think GM should use a reversible heat pump as part of the HVAC system (something that can act as both AC and heater).

(Quote)
Tagamet Says:
January 2nd, 2008 at 8:48 pm

AES
The heat exchange idea sounds neat, but is it a layer of complexity that could be covered by something “simpler”? I think that Volt 1.0 needs to be as bulletproof as possible, if for no other reason than Murhpy’s Law combined with the tight “get it to market timeline.
God Bless,
T

(Quote)
AES Says:
January 3rd, 2008 at 11:49 am

Tagemet-

As far as I know, a heat pump is just an AC working in reverse. So it wouldn’t add any complexity, it would reduce it. The Aptera is using a heat pump as a part of its HVAC system. See this link:

http://home.howstuffworks.com/question49.htm

(Quote)
Tagamet Says:
January 3rd, 2008 at 12:08 pm

AES

“Complexity” is one of those highly interpretable terms. In this case, I was thinking in terms of “moving parts”. I totally agree that a heat pump could work well, I was thinking in terms of a more passive approach, like the heat sinks on computer chips that get VERY hot and are also in an enclosed space. The heat sink coupled with a tiny fan (one moving part) is very efficient too. Granted, a heat sink wouldn’t help warm a seriously cold battery but that half of the equation might be handled by a little bit of the battery’s own “juice” (again, with no moving parts). Fewer moving parts would imply less weight, too. Especially when a heat pump’s compressor is part of the solution.
Whatdayahthink?
T

(Quote)
AES Says:
January 3rd, 2008 at 5:53 pm

I’m a big proponent of having few moving parts as well, and there are probably already rudimentary heat sinks built into the battery modules, if not the cells themselves. I have some photos of the 35kWh battery packs that A123 built for Orion hybrid buses, and the cells are housed within thin metal module cases that also seem to act as heat sinks (although don’t quote me on that). They seem to do that systems’ active cooling using large fans and generous space for airflow.

Regardless, if they’ve got the Volt’s liquid cooling system in place, they’ve got the capability for heating as well, although I think you’re right that the cells might produce enough heat on their own to be happy on a cold day.

(Quote)
Jim I Says:
January 3rd, 2008 at 6:23 pm

AES #36:

The batteries giving off heat while in operation is not in question, so they would need cooling of some type, and we have been told it is a liquid cooling system.

The problem is when it is below freezing outside, and we go to use the vehicle. Unless the battery pack is kept warm, the performance will be terrible.

For example, this morning my garage temp was about +40F. When I got to work at 8:00 AM, it was +8F. The high temp for the day was +22F. Right now, at 6:15 PM, it is back to +16F. The car has not been run all day and it was outside. Without some warming of the pack, I would be concerned about what effect the cold would have on the battery pack.

I assume that the engineers have worked out, or are working on this set of conditions.

(Quote)
AES Says:
January 3rd, 2008 at 7:21 pm

As far as I know the operating temperature for the LiFePO4 or manganese cells is good enough so that the electrolyte won’t freeze. But yes initial performance would probably suffer. Flash heating for instant performance after starting up would probably be best accomplished using something electrical rather than liquid-based. A heat pump operating in the winter would probably have its external coils periodically freeze up anyway (not much ambient heat).

We’ll see what GM comes up with.

(Quote)
Modifications Electronics Engine Management Systems Says:
January 31st, 2008 at 2:57 am

Recent GM-Volt Forum Posts

New video: Volt drive in Detroit November 19, 2009
November 19, 2009 Detroit Free Press story with video featuring a Volt drive with Andrew Farah in... […]
srschrier
New Video: Volt Corrosion Testing November 18, 2009
From GM VoltAge, the Volt's corrosion... […]
srschrier
Th!nk picks Indiana for U.S. factory November 18, 2009
Th!nk picks Indiana for U.S. factory: _Link_ (http://www.allcarselectric.com/blog/1038564_thnk-picks-indiana-for-u-s-factory) […]
Jason M. Hendler
FIRST ALL-ELECTRIC APTERA 2e PUSHED BACK TO 2010 November 18, 2009
FIRST ALL-ELECTRIC APTERA 2e PUSHED BACK TO 2010: _Link_... […]
Jason M. Hendler
Any news about the NiMH battery? November 18, 2009
Now that there are new owners of the patent, is there any indication that they will allow its use for electric cars? Like many others, I believe that... […]
Desertstraw
energy requirments of modern electric vehicles November 18, 2009
does anyone know any credible sources of information concerning the electricity requirements of modern electric vehicles per mile of travel and the... […]
crubkings
30% reduction November 18, 2009
The Belgian governement decided that if you buy a car with less then 60g/km emmision you get a 15% tax reduction and you can write it off for 100% if... […]
filiep

Are the Volt Prototype Packs Running Too Hot?

39 Responses to “Are the Volt Prototype Packs Running Too Hot?”

Leave a Reply

Recent Posts

Recent GM-Volt Forum Posts