Exploding cell phone kills store employee
I was just wondering whether to finally sacrifice my loyal and beautiful Nokia cell phone for something more contemporary when I discovered that a couple of days ago China experienced its ninth cell phone explosion since 2002.
In the latest, a sales associate in a computer store in Guangzhou apparently charged his new cell phone battery and put the phone into his shirt pocket. It then exploded, severing his neck artery. He bled to death.
Chinese police have not declared the make of the phone or of its battery. But both Nokia and Motorola have denied links to problem batteries in China, declaring them to be the creation of counterfeiters.
Look, I am the ambassador of the normal, slightly tech-skeptic street person on this site. And, because I know clever technological people read this blog, I would be interested to hear how it is that cell phones can blow people to death.
This is from a gas station in Redwood City, Calif. Does this include AT&T cell phones?
(Credit: CC Ten Safe Frogs)I would very much like to know the chances of such an event occurring in the United States. And I would be very much soothed to have some sense (you know, some odds or at least a semblance of an over/under) whether one brand of cell phone might be more likely to blow up in my face rather than another.
I am extremely sad that an unfortunate employee lost his life because of an apparent cell phone battery malfunction.
And I would like to head to my trusty, if occasionally shifty, AT&T superstore, armed with all the available information that would minimize my chances of being offed while texting sweet nothings and requests for money.
I cannot believe for a moment that any US cell phone might be prone to such a murderous occurrence, but I regularly read the comments left on the blogs of fine writers such as CNET's Matt Asay and Don Reisinger and I have been consistently amazed by some of the information that comes out in these forums.
So please, put my mind at rest. It might, at the very least, make AT&T some money. Unless you tell me to change to Sprint or Verizon, of course.
Chris Matyszczyk is an award-winning creative director who advises major corporations on content creation and marketing. He brings an irreverent, sarcastic, and sometimes ironic voice to the tech world. He is a member of the CNET Blog Network and is not an employee of CNET. 
Unfortunately, what I know will only worry you more. I was an engineer for Intel Corporation for 12 years. One of my last engineering projects was a research experiment on the effects of temperature on reliability of electronics in a cell phone.
During the project, I was sidetracked a little, because the temperature range of what a cell phone would see in "use condition" worried me. Without going into too much details, let's just say that a typical cell phone will see temperature range between -10C to 120C. 120C? You might ask. Yes. 120 degrees C. That's because even an average person will very likely put their cell phone in his/her car where the temperature will likely reach over the boiling point of water.
Then, I did a little research on various components of a cell phone, and looked at what temperatures they might fail at. The battery became a big focus.
From what I learned, the batteries have become mini-bombs over the last 4-5 decades. Of course, you might have heard of some "exploding battery" stories.
But I would suggest that you also look into laptop batteries, because they are the SAME technology as the cell phone batteries.
Not long ago, Sony recalled their laptop batteries for the 2nd time in recent years, for potential "fire hazards". About 2 years ago, an Arizona man's truck burnt up in flames from an HP laptop computer (battery) that was running too hot in the passenger seat.
The trend could be traced back to mid 1990's, where some cell phone batteries were exploding or catching fire in Taiwan or Hong Kong.
If one look into the incident reports, they all indicate that the explosions occurred (1) where it is hot condition, or (2) high humidity.
All cell phone battery makers have a manufacturer's disclaimer that "warns" user NOT to charge the batteries at conditions higher than 45C. Most if not all battery makers also put in "shut off" circuits in the batteries to prevent charging when temperature is over 45C.
However, apparently, these circuits do not always work. (otherwise, Sony would not have instituted 2 separate recalls for batteries.)
Sony also wasn't the only one, and NOT all causes are "counterfeit". Nokia themselves last year instituted a recall of "genuine Nokia batteries" made by a Japanese Company.
Any how, It's late, and I'm tired. Must be off to bed.
If you have questions, feel free to contact me.
Chen Gu
It's readers like you who make the whole thing worthwhile. Thank you for your insight. I learned so very much. And I suspect a few other readers did too.
Chris
Thanks for all the info provided so far.
After I lost my 3rd phone this year, I've decided to get really cheap slim phone as replacement and ventured into the world of "China phones". For one third of the usual price from the well known brands, I get all kinds of functions like I can view TV and 5MP Camera and some of them are more stylish then the brands I've used before.
I was eyeing two China made models when I noticed the big difference in the quality of their camera although both models has "8MP" etched at the back of the camera. When questioned, the sales lady indicated that those are printing errors, it is really 2MP and 5 MP respectively.
The phones are so cool that I do not really care if they do not hv camera function or if they stop working after one year. But my concerns are :
1. If there are already printing errors (regardless deliberately misleading or by accident) at the outside, would it mean that there could be even more problems in the inside and hence more likely to explode?
2. If it's really really thin, like 5 mm or less and is packed with functions like TV etc, will it be more likely to explode?
3. Last but not least, if it's a unknown brand made in China, will it more likely to explode? I have been googling and it seemed to me phones explode regardless the brand or where it is has been manufactured. Most news does not reveal info.
Thanks in advance!!!
From what I have read, generally, OEM batteries are better in reliability, though no one has ever really shown any solid evidence of that better reliability. If one reads all the incident reports, the explosions in the early 2000's were mostly aftermarket batteries, BUT that was when aftermarket batteries flooded the market in Asia. Nokia and others used these incidents to highlight the dangers of aftermarket batteries, and campaigned for the "Genuine Nokia" labeled batteries. In more recent years, however, it's the "genuine batteries" that are exploding more.
In the aftermath of recent Nokia battery recalls, number of explosions of nokia phones were reported in India. 1 exploded in a kitchen, and nearly injured a pregnant housewife standing nearby. 1 exploded under a pillow, while a man was sleeping, injuring his face. 1 exploded in a cell phone store, the explosion was so loud that people near by thought it was a terrorist bombing, and all ducked for cover. Nokia made no conclusions as to the "genuineness" of these batteries, but also didn't deny that they were indeed "genuine Nokia" batteries made in Japan.
Last year, a motorola cell phone exploded in China, also killing a Chinese man. The man was a steel worker. The phone exploded in his chest pocket, and a fragment of it shot into his heart. Motorola claimed it was counterfeit battery, but they took the phone fragments and never released any findings. (I guess we'll never know now.)
The problem is, unfortunately, one cannot tell if the battery is good or bad just from the outside. (There are some OBVIOUS bad signs, like if the battery has a visible bulge, it's likely that it is a very bad battery.)
Cell phones and laptops are so proliferated in modern life that people don't think about their safety. They just assume that these devices are safe, but the batteries now have enough energy densities that literally they are bombs. Even in the early 1990's, gel pack batteries were extremely dangerous to work with, because an accidental shorting can cause explosions.
If one googles for "battery recall", one can find Verizon, Kyocera, Dell computer, etc. all issuing recalls. UL (Underwriters Laboratories) have safety standards for batteries. UL 1642 is specific for Lithium Batteries. Some of the sections are very noticeably alarming: (1) some batteries in temperature testing are known to "explode", (2) test technicians are instructed to "never approach a lithium battery when the surface temperature is over 90C", (3) sample size for most testing is ONLY "5 batteries". Yes, if Nokia tests only "5" batteries, and they pass, then MILLIONS go out to the consumers.
My problem with this standard is that it does not test for "Thermal Operation", where one would charge/discharge the battery while at high temperature. UL 1642 only tests for operation at 60C, and a separate thermal test to heat a non operating battery to 150C for 10 minutes. These tests are unrealistic to normal use environments. 150C is the theoretical limit for Lithium batteries, when thermal runaway reactions will occur, even for the best batteries.
A typical cell phone battery will rise in temperature by 20C (measured on the external surface) during charging. That means the internal temperature rise is even higher, probably 10 to 20 degrees higher. Inside of one's car can reach temperature of 120-130C. If one is charging at that temperature, the interior of the battery can get up to 170C!! And that temperature in the car will last for at least 2 hours. Even the best batteries will not last at that condition.
I honestly think that because these batteries are now so proliferated, and there are so many of them out there, much higher test samples and safety standards are required, and rigidly regulated by governments. I mean, imagine one of these things going off on an airplane. (There was a report of a Thinkpad laptop battery that exploded in the LAX airport.)
But for the consumers, here are some safety tips:
(1) use a OEM battery when possible.
(2) ONLY charge battery in a cool shady dry well ventilated spot.
(3) Do not leave your cell phone in your car. The hot temperature will slowly degrade your battery, even if you are not using it. Over time it could become an explosive hazard.
(4) Do not charge while you are using the phone. That's like putting a bomb next to your face.
(5) If a battery seem to "leak", even when not in use, get a replacement battery. Chances are, that battery is already bad.
(6) when replacing batteries, try cleaning the terminals of any dust.
Thanks a lot for that info!!! It is much appreciated!! ^^
Y'know...consider how many lithium ions are purported to be in a Tesla, just how BIG of an explosion would THAT BE should an oopsie occur in that car?
Yes. The Tesla. Very interesting thought. What about the Prius? Just doesn't go fast enough?:)
Chris
But Nickel metal hydride batteries will also explode in some conditions.
However, Prius and Lexus hybrids locate their batteries under the cargo hold, in the underside of the car. There is a very good engineering reason for this.
That particular location of the vehicle is the coolest shady spot, pretty much near outside ambient air temperature.
Under these cool conditions, the batteries will not likely explode.
LEATHER SEATS rule in this situation.
Staticly charged? Before the day is out, I'm not sure I'll ever leave the house again.
Thank you for commenting.
Chris
It is true that exploding batteries can be from either brand names like Nokia and Motorola as well as counterfeit batteries. I suggest reading our Battery Care instructions (http://www.batteries4less.com/contents/Battery_Guide/cell-phone-battery-care.html) or learning more at http://batteryuniversity.com/ Battery University is our main guide for learning about battery chemistry and provides in depth explanations of the danger of lithium ion batteries.
In response to nouser's comment, it is not easy telling whether a battery is a problem unless there are symptoms. For example, a battery should never get hot while charging. If it does, either the battery or the charger is likely to be defective. Discontinue charging immediately and replace the battery. To put your mind at ease, it is very very unlikely that a cell phone battery will explode. There have been millions of batteries sold since the advent of cell phones and there have only been a few problems. I keep an eye on this issue very carefully so I can tell you that I only see news articles once or twice a year. No Ammo Box Needed!
If you have more questions, call us at 800-300-9993 and we can give you more advice about making your battery choices. I can be reached at coryon@gmail.com
Cheers,
Coryon
I would dispute 1 of your statements. "A battery should never get hot while charging". This is simply not true. Even a basic lead acid battery will get slightly warm during charging. I have made temperature measurements of cell phone batteries during charging, they all get a little hot.
The charger does not really know what the battery is capable of withstanding in it's charge rate, which is why you should always use a charger that is specified for the battery you are charging. These aftermarket 'fast chargers' can be dangerous if used with a battery that can not handle the rate of charge. If your battery won't charge with a moderate rate charger, that keeps the temperature safe, then its time to get a new battery.
Getting warm during charging (slightly above room tempurature) is normal (as is any circuitry with electrons flowing), but if it gets as hot as say a fresh cup of coffee, your pushing the charge too fast. This can happen even with OEM specified chargers, as they are sometimes making a descision for the specs hoping to advertise a short charge time, and not realizing the safety hazard. Maybe the battery can handle it, maybe it can't, I don't want to find out the latter, I'll wait the couple more hours for a safe charge.
Lead acid batteries charge faster when warm, as most chemical batteries do, because warmer means faster chemical reactions, more molecular movement, but there is always a limit to how high this temperature should go, it should never go high enough to suprise you upon first touch. If it does then you are charging too fast. car chargers are the absolute worst for regulation, they typically rely upon a set voltage limit of the charger (above the charged voltage of the battery assumed to be 13.8V, to reverse the current flow) and complete disregard of any current regulation simply falling back on the current limits of the chargers components, and typically no compensation for internal battery resistance (which can vary widely). A high internal resistance can lead to longer charge times, low resistance can lead to over voltage/current charging and both result in higher temperatures. As the batteries charge goes up (voltage) the voltage difference decreases, and thus current flow slows. But if the battery does not charge up, and the voltage difference does not decrease then the current just keeps poring in, and it heats up a lot. I have seen batteries boiling in their own juices, when the battery was just to weak to take a full charge, with an unregulated charger. Use chargers with both Voltage and Current regulation, and know it matches the specs of the battery you are charging.
guchen and techman21, my basic rule of thumb is if it is as hot as a cup of coffee (where you need one of those cardboard jackets), its too hot, and your safety risk goes up exponentially from there. You may have gotten away with it a 1000 times before, but do you really want to find the one time you won't? Keeping it below this temperature wil ensure that charging wil not be the cause of explosion, but then you always have impacts causing internal shorting to worry about....
- by ryxramos78 July 31, 2009 10:23 PM PDT
- hey chen gu! we are studying cellphone operating conditions reliability. is there any way you could help us? We are planning on putting the cellphone in an oven or refrigerator and see if the RF signals will be affected by this temperature changes. However, we need a baseline data on what temperatures we need to set the ovens. maybe you could help us.
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