Tests and Scans
The Pit BLOG
Playing with Fire: Part II
Rob: Hi, this is Rob Cheng. It's October 13th, 2006. I'm here with Tony Olson who is an old friend of mine that I worked with at Gateway. He was the Vice President of Engineering. Tony started a brand new company called D2 Worldwide and he has a lot of insight into the portables and what's going on there. Tony, first tell me a little bit about D2 Worldwide and how you learned so much about the portables.
Tony: Thanks Rob. At D2 Worldwide, we're an Engineering Services Company and we really are all about the end customer. Everything we do is to try to make products better for the end user, for big name brands who have either outsourced their engineering or brands who don't really have engineering in house themselves and around this issue in particular, we're all about customer safety. We have worked with just tons of manufacturers across a large number of products, not only testing and working with their design, but actually working with forensics of units returned from the field to help them dissect what happened. Specifically on some of these lithium battery issues and really to help them make sure that this doesn't happen again.
Rob: So, Tony, you're seeing the various portables from various manufactures in your labs that have blown up using lithium batteries.
Tony: Exactly. We've worked through actual units that have been in the field and have torn them apart and gone through the forensic process of working with what happened and then working backwards and looking at what happened at the manufacturer, what happened with the protection circuits and things like that to help make these products better and safer for the end user.
Rob: Great, Tony. I guess we'll just get right into it. What is your view about why some of these portables are exploding out there now a days?
Tony: Well, you know it is interesting. There is certainly the specific case that started all this with Dell and I think what's out there is probably the very likely case is what Dell is saying is that in the Sony battery manufacturing process, some contaminates were introduced into the cells of the battery that allowed them to short out and overheat. And then, in some traumatic cases, if you've seen the pictures on the web, then with some violent flames. But really, that's just the tip of the iceberg. I think the lithium ion itself is a very unstable technology, unstable lithium metals is an unstable metal. It requires lots of precautions in manufacturing and it needs to be used properly and safely.
Rob: Tony, let me interrupt for a second. Is this problem related to strictly to lithium ion batteries in particular?
Tony: Well, batteries in general, I think, have some need for caution and I think people take them for granted too much. Any kind of power source like that has a possibility of going awry, but lithium ion in particular because of the lithium metal and because of the energy density, and I think in some cases it is 5 times more energy dense than the last battery competitor, it has an awful lot of energy to release, which is really good when you want to use it over many hours on a laptop, but it is really bad if it gets released very quickly.
Rob: Like in the fire.
Tony: Exactly, exactly.
Rob: Okay. Tony, give us a little, I guess, lesson about lithium ion and what's going on inside of the portable when it is kind of exploding and what's happening and what's going on there.
Tony: Okay, sure. Lithium itself is actually a very combustible metal. One example I was thinking about this over the weekend and a similar example a lot of people might remember from their high school physics or chemistry classes is magnesium. A lot of times a professor would light a strip of magnesium and it would burn very brightly and even sometimes they would throw it under water and show it would continue to burn even though it was under water. A real world example people probably see regularly is those trick birthday candles. Have you ever seen those things where somebody blows them out and they think the candles are all blown out, but yet they burst back into flame. Those candles actually have a little strip of magnesium in there. The reason I'm bringing those examples up is here is two cases where you think that the normal way people think about putting out a fire, whether it's paper, wood, or something like that would work, doesn't work with lithium. And that's really the root of what's going on here. Basically what happens in a lithium ion battery is a short circuit is what causes overheating and overheating then starts to release more oxygen and you have everything necessary inside those cells to continue combustion. You have oxygen being released, you have the flammable materials and the process of once it starts, really just runs on its own. And then all of the protections that you may have around are really too late to do any good at that point.
Rob: Tony, what can the portable manufacturers do in order to eliminate this problem?
Tony: That's a good question. Let me go back a little bit to tie into your previous question too. What causes this? There is really a number of different elements that can cause this to happen. Today what's in the news is these contaminates and what happens with these contaminants is they ended up causing short circuits within the battery itself, but there's others also. There's overcharging that can happen. Lithium batteries are very sensitive and they need to be matched precisely with their charging circuits. If a lithium battery is attempted to be overcharged it again can overheat and as it starts to get into that scenario, you get right back into the same sort of breakdown where the internals can start to boil, that can lead to short circuiting and off we go again. In addition to that, similarly overheating, just overheating from the outside in, even if there isn't any charging being applied to the battery, it can also lead to that same condition and then a third case is actual damage and this is one of the ones that concern me because literally if there is some damage to the cells which can cause a short circuit to start, that process can begin and actually erupt later on. Most unexpectedly by people, think of some examples and this is a hypothetical example, but let say students running around with a knapsack with their portable in it and just kind of throwing it down on the ground and bouncing it hard against a rock, they may not worry about it with books or other materials, but that could start that kind of chain reaction. Two real world examples I read about. One was in 1999 in LAX, they were loading a pallet into a cargo plane and the loaders noticed that the pallet was smoking, so they pulled it out of the plane and on the ramp as they were taking it off, it burst into flames. It turned out that was a carton filled with lithium ion batteries and there was obviously, and they were just packaged, so there was no power source to them. So it shows the damage of that can happen. There's another case of a guy who was flying a remote controlled plane and he crashed his plane and packed everything up and threw it in the trunk of the car, including the battery, and again, these batteries are very light from their energy density, and threw it in the trunk of his car and was driving off and it ended up later started the reaction, exploding in the trunk of his car. So, all of these are different mechanisms that can happen.
Rob: Sounds like there's multiple ways that can cause these batteries to explode.
Tony: Yeah, exactly. So, going back to your question, now the second part of that question, what can manufacturers do. There are really a few things that people absolutely have to do. One is on the units side, on the laptop side, on the charger side, is making sure that there are, what's called, the protection circuits. And there needs to be redundant protection circuits in these systems, wherever lithium ion batteries are used. They need to make absolutely certain that these batteries are protected from overcharging and from over current. And these are devices that are inside these units that will actually shut off the power supply to the batteries. If this type of condition starts to occur, and these are in many places, these should be commonplace today. The other area, I think, and I wonder if this is part of the problem that we're seeing with portables today. The other part is really getting strong specifications and tests in place with the supply chain to make absolutely certain that these batteries are built without contaminants. Then the batteries themselves need to have protection circuits in them also. The best batteries, by the major named brand manufacturers, typically have both a thermal protection switch in there, and many times it's called a PTC, and they also have a pressure sensitive switch in there so that if the temperature starts to rise inside the battery, these detection circuits inside the packs of cells will cut off the electricity that is being supplied to the cells and the same thing is true with the pressure sensitive, it will actually ... in that case the pressure will yield the battery unusable and should stop the reaction so these kind of things absolutely need to be ….
Rob: ...stops working rather than blows up. The circuit is designed to do that.
Tony: Exactly, exactly.
Rob: Okay. So, Tony, why is it that we're seeing so many on portables, in particular, yet we're seeing so much about it, these violent fires, but you know the other rechargeable devices, even with lithium ion, they're not making the news, we're not seeing the big fires. Why is it so much more focused right now on portables?
Tony: That's very interesting because lithium ion in other devices are not any more inheritantly safe than they are in portables, but what I think what's happening is a couple things. One is lithium ion batteries are in lots of portable devices. They're in cell phones and they're in all types of portable and smaller portable devices now. But, I think that there are a couple things happening. One is the batteries in portables are much larger than typically any other portable device because of the amount of power that those devices consume and the amount of time that consumers want these things to last. So, the sizes of the cells, the number of cells, it is much, much bigger. And I think that because of that, also when the reaction occurs, there's a lot more energy there to be able to violently erupt so when it does occur, it's a much more traumatic failure. So, I think that's one reason. I think a second reason is there are a huge number of portables out there. I think that right now, as of this morning, I think I read 7 million batteries are on recall. And that's just a small portion of the overall portable computer environment. So, the opportunity is just gigantic and then the size of the battery makes the failure even more traumatic. I think those are really the main reasons. There's probably a third piece to this, which is very interesting. If you look at the supply chain, there's a constant pressure on portables to try to get computers, in general, to try to get lower prices, get more energy, have the laptop have more battery life, and at the same time continue to shrink in size. That puts a tremendous amount of pressure on the supply chain to try to deliver a smaller size, lower cost; more energy density and I think that in some cases, maybe pushing the technology beyond where certain people in the supply chain have the capability to deliver it safely. There was an interesting paper, and this is a little bit more than speculation, having been in the industry, there's a paper in IEEE Spectrum, that is in one of the May issues that actually touches on this issue of the supply chain and different layers of outsourcing and I think some companies, and I'm not necessarily saying this is at all what happened with Dell or with Sony, but they kind of lose control of that whole process given all these specific pressures that are happening in the industry.
Rob: Okay. So, I guess the next one is kind of the worst question, but it has to be asked. Is this issue just isolated to the few big manufactures that have announced using Sony batteries or is this problem much more wide spread, or about to mushroom? What's your look on that?
Tony: Of the problem at hand with the contaminated lots of battery cells should be, hopefully, pretty well contained. Although, even having said that early on when Sony first announced this, they said it was only going to happen with Dell portables that they had that as a separate line and it was not going to happen with other manufacturers. Well they obviously have already recanted that statement, so that draws another level of question into the how much control do they have on the processes of which lines. But, even stepping out of that, back to what we talked about earlier, how can lithium ion be put into a condition to ignite. There are other situations beyond just contaminated cells. Again it goes back to the charger circuit, the protection circuit, and even the way the users ... what kind of environments they put these in. So, literally, any lithium ion battery has the potential to do this. Obviously, ones that have this contamination; it is even a greater possibility for that to happen.
Rob: Another question here, just for the users, just as a practical question. Does the problem only occur when the portable is on battery power or does it also occur when it is connected to the wall? What can us users do to be more cautious about this issue?
Tony: Yeah, that's a great question. I think that consumer safety is really important in this one because of the violent nature of this failure. The safest thing to do is certainly, in normal operation, would be to take your battery out and plug your laptop directly into AC. And certainly anybody that has one of these potentially affecting batteries that's showing up on the recall list should absolutely do that. Remove that battery and just run it off AC. You're not immune to this condition. You really in any state, and I go back to that example of those pallet of batteries that were just packaged together and they ended up igniting. Probably because of some damage that happened in the shipping process. The probability does go up and is more likely once you're charging as you're re-energizing that cell, more likely to happen. But, the only perfect case is if it's removed from the portable.
Rob: Another question for us users out there. Is this issue more likely or less likely to happen the older the portable is or the more it is being used or is there any way to know whether the probability of my portable is higher or lower and it might happen on my portable?
Tony: There's a couple ways to look at that. One, and I can't substantiate this, but what I've read is that as battery technology progresses, both the solution or the chemical that is used inside these batteries as well as the packed material and the protection circuits continue to get better through the years, so even though this issue is happening now, it's come to the forefront right now, generally speaking, if you have an older battery, an older lithium ion battery, it probably is in general more at risk than some of the newer batteries. The other thing I think people should really be aware of is they need to stick …
Rob: ...just to make it clear for everyone out there. You are not saying for everyone to go out and buy a new battery because there's a bunch of issues there as well.
Tony: Right, I'm not saying that. But just to look at it as a user, you're probably at greater risk. And at some point, lithium ion batteries typically only last 18 months to 2 years anyway, their useful life. So, there should be a natural sort of a battery turnover as well. The other thing and probably the bigger issue, I would say, is people really need to stick with the big named brand manufacturers. They need to be careful of, very careful of knock offs because as you start to get into those, those different types of channels, and even counterfeit batteries in some cases that I've read about. Those manufacturers are not necessarily taking the care to put the protection circuits in or even put them in properly and in a way to try to cut costs and compete with the big brands, so there's some additional danger there potentially.
Rob: Okay, to finish up here. If my portable suddenly did burst into flames, what do you recommend that we do? I mean, it seems like this is not your typical kind of fire, so what should we do?
Tony: Yeah, it's not typical. If you think of a typical fire, as you know, a piece of paper is on fire or wood, you can just douse some water on that kind of a fire. This is not, at all, that type of fire. This is, actually, literally, lithium is a metal and metal burning requires some very specific handling. You should not use, not, I repeat, not use any of the common extinguishing agents like water or foam or vaporizing liquids because those things can actually cause an even more violent reaction, potentially, as it hits that lithium metal. Really the best thing to do, is if you have it handy, is to use like a Class D dry powder. Those are specifically developed for metal fires.
Rob: Like the fire extinguisher. Is that...
Tony: ... exactly, in a fire extinguisher, look for that Class D rating. The very first practical thing is a step back. I mean, get away. If you notice it starting to go, get away from it and get people around you away from it because usually this is going to happen within one particular cell first. But, again, going back to portables using many cell packs, packed together what looks to you like one battery, may be six, eight, or more cells inside of that pack. Once that reaction starts, it's going to cause, potentially, the subsequent cells to go. So you may get a little bit of a timed release and the venting can be violent, I mean it can,... even the first one, it may change by the battery as it gets hotter. It may just ooze the liquid out if it was just burning hot enough to melt the cell of the plastic, but as it gains in power, then the next one then may pour violently and actually spew flames, so you don't want to get any of that material on you and you obviously don't want to get any of that fire on you, so step back. And even with those fire extinguishers, the goal of those extinguishers is to kind of rob oxygen from that process. It kind of coats that process allowing the burning that will want a fending cell to kind of cool down to stop the forward reaction. But there's no guarantee that's going to happen. If that chain reaction has already started in the next cell, it may appear as though the fire is out, but it may burst up again, similar to that little trick birthday candle example I brought up. I think there is actually a case of a Sony VIO that the owners thought, it did burst into flames, they thought it was completely out, and then it burst up again a second time. Fortunately, they had moved it out to the driveway at that point. So, caution is really the rule and really stand back and if you don't have the right extinguishing material, best to call in the experts. Call the fire department or something like that. Don't take a chance to try to force something on there that may cause more damage or may make the fire spread.
Rob: Well, Tony, I want to thank you. This has been very, very interesting for me and I've actually heard this all for the second time, so I hope all of our listeners out there really enjoy all of the information you provided and hopefully we'll see you on another podcast in the near future.
Tony: Great. Thanks, Rob.Join the Discussion