Flaming Cellphones

phorm writes "Many of us have heard the urban legend of cellphones causing fires at the gas pump, but how about the hazards of replacement batteries? Reuters is carrying a story about a woman whose cellphone burst into flame, causing her superficial burn injuries. According to Nokia, the problem has occured before, and is related to non-brand replacement batteries. For various reasons, these batteries may overheat and catch fire, or even explode! So far I haven't found much info on whether this has happened with other brands of phone, though I do know that my little flip-phone gets very hot when running in analog mode. Perhaps some slashdot readers have had a similar experience?"

Comments

Other brands of phone - Siemens

[Animaether]

From a Dutch article*

A spokeswoman for Siemens said a GSM (cellphone) of the Siemens brand exploded last year in Germany. It concerned a phone that was placed in a carkit. During recharging, the phone had overheated and exploded. Nobody was injured in that incident. The user of the phone had bought the battery at a fleamarket.

* http://nu.nl/news.jsp?n=193292&c=51

Re:Other brands of phone - Siemens

[mindriot]

Heise has had an article on this as well. Translation follows.

Normally, one would only see this kind of stuff happening in rather bad secret agent movies, but now it happened to a woman in Amsterdam: Her cell phone exploded. These news about the exploded mobile phone are likely to disturb many cell phone owners: "Could this happen with my phone too?" In the Netherlands city, the woman's phone had first fallen to the ground. When she turned it on again and held it to her ear, the device exploded and caught fire. The woman suffered minor injuries. Experts, however, see no reason to be concerned: Cell phones explode extremely rarely, according to Bernd Schwencke, head of the cellular phone testing department of the German Quality Testing agency, Stiftung Warentest, in Berlin.

"Up to now, no such case was known to me," Schwencke notes. According to him, what's unusual about this event in the Netherlands is that the phone did not catch fire during recharging as in previously known cases, but while using the phone. In previous cases where the rare case of a mobile phone catching fire occured, forged batteries were spotted as the cause. This was also the cause when a Siemens phone caught fire during recharging in a car kit. The phone manufacturer was not responsible -- the device was equipped with a bogus battery that was not properly working. "The accumulator had no overcharging protection and simply burst like a balloon filled with too much air," says Stefan Muller, spokesperson for the Siemens mobile phone division in Munich. Unfortunately, the plagiarized products mostly originating from Asia are still a problem, according to Muller. To prevent the use of such "time bombs" in cell phones, the experts advise to only buy batteries in specialized stores instead of flea markets -- even if a manufacturer's logo is on the battery.

Re:My Cellphone is Cool....no really.

[shepd]

The battery was shorted out.

With NiCad batteries, this means several amps of current through a wire mean to handle perhaps .3 amps.

That means heat.

It doesn't mean the cellphone will spontaneously set on fire. It will only happen if the phone is damaged to the point the battery is shorted.

Full power!

[ChilyWily]

So far I haven't found much info on whether this has happened with other brands of phone, though I do know that my little flip-phone gets very hot when running in analog mode. Perhaps some slashdot readers have had a similar experience?

Yup, analog transmits its signals at full power compared to other technologies like CDMA which dynamically adjust their power based on various factors (such as the signal to noise ratio, signal strength, how other cellphones in the same area are transmitting etc). More power for the signal requires a faster rate of discharge which translates into a more rapid chemical reaction that produces the heat in the battery. The issue with non-standard batteries (especially the cheap ones) is that they're not rated for the peak power consumption of the 'brand' phones - thus when the phone demands a surge of power for an extended period this stuff is likely to happen.

Re:Full power!

[linuxtelephony]

Analog does not always transmit at full power. If memory serves there are 7 power levels that are used and the cell sites can tell the phones to step down their power to one of those 7. It all depends on the quality/level of the signal being received by the site. If it isn't that good, the site says turn up the power. Problem with lots of handhelds is that the antennas are in cars or have other obstables to transmit through thus they are told to transmit at the higher power levels.

Handheld cell phones are limited to somewhere around 0.6 watts. Typically, the newer digital phones (at least from about 3 years ago) would typically have max analog power near 0.5 watts. In digital mode they often can go lower, with CDMA phones transmitting lower still (in theory).

In this case it would appear the phone was dropped. When the phone was turned back on it suddenly ignited. This would seem to indicate a severe short somewhere, and no safety circuit to cut power in case of short, if any such circuits exist on any batteries to begin with.

Typically you hear about two kinds of damage to cell phones. The most common I've heard of is batteries catching fire or exploding during the recharge process. And this is perfectly understandable -- feel a battery while it is getting recharged, they can get pretty warm. Some phone batteries would get so warm while inside the phone on the recharger or plugged into a cig. adapter that they would melt the plastic case of phone itself. I know some "rapid" car cig. adapter chargers from phone vendors have special circuits to control the charging, and the generic cheap adapters don't have the same circuit (if at all).

The other heat related problems I've heard of with cell phones is from extremely long transmissions. Say a handheld phone plugged into a cig adapter and used for 200+ minutes. The transmitter can get pretty warm, and I've heard of some of the smaller/thinner plastic phones (early MicroTAC? don't remember for sure) had plastic melt.

I've never heard of a phone bursting into flames, melting the case, or otherwise get hot when it was not directly related to recharging or extended use. At least not until now.

Something had to be pretty severely damaged or there was no safety cut off circuit somewhere to allow a cold phone to burst into flames like that. Sometimes those bargain batteries and accessories aren't such a bargain after all.

Here's my question. Did she get the battery used in this phone from the same store she got her phone from? I've bought several phones over the years, and the last few years you just about could not find OEM parts, the carrier stores had the cheap stuff there in packaging with their carrier names on it. So, if she bought her phone from a carrier store, and they gave her the battery, then would that carrier assume the liability for this happening, since it was not a Nokia battery involved?

Lithium Ion batteries and overcurrent protection

[freshfromthevat]

Many LiOn batteries include built in gas gauging and over current protection. This costs about $1 in parts. Dallas makes some of the gas gauging parts -- DS2438 for instance. The gas gauging component is connected to the telephone via a 1 wire + ground interface. The overcurrent protection circuit is entirely internal. If the clone vendor wanted to save several nickels they could leave out the overcurrent chip and nobody would be the wiser until the battery shorts out.
The reason the overcurrent protection is built in is because Lithium Ion batteries will reach the flash temperature of plastic if current is drawn from them too fast.
So... don't rip the plastic off the pack and short them out except by remote control.
Thankyou.

LiIon can easily thermal-runaway

[SuperBanana]

For various reasons, these batteries may overheat and catch fire, or even explode!

Lithium Ion batteries will do this very readily when drained or charged too fast...or if overheated past a certain point under what would otherwise be normal current draw...and it's one of the reasons, for example, Panasonic won't sell me the cells I need to fix my Powerbook G3 Lombard's battery(almost all laptop+camcorder batteries, save the newest, are simply AA-sized LiIon cells in various series+parallel configurations).

Panasonic won't sell to anyone except a 'certified systems designer' who has signed agreements saying they'll design proper charging and current/temperature limiting circuitry. God forbid you should simply want to fix a battery pack which is no longer made. I suspect they do it mostly to keep battery pack repair impossible and force everyone to simply run right out and drop $50(cell phones) to $300(some laptop batteries). Sound conspiracy-theory ripe? :-)

LiIon is actually a pretty crappy technology, at least as far as consumers are concerned. Nobody told consumers that for the extra talk minutes they got, their battery will be damn near worthless in a few months if they use their phone a lot...because LiIon looses a staggering amount of its capacity with every charge/discharge cycle- and the deeper the discharge, the more capacity is lost with each cycle. NiMH batteries don't have this problem. Funny thing, eh?

Even worse, the batteries never get recycled(you think the consumer drives to the town dump and puts the battery in the battery recyling box? Nooooooo), they simply get chucked. There are some really nasty chemicals in LiIon batteries(like just about any battery technology today.)

By the way, speaking of batteries and the environment, a lot of people have trouble with car batteries and simply buy new ones instead of taking care of their car battery better(granted, car batteries are usually recycled better, because it's easier, and there's a lot of material, but still...) This site covers just about anything you ever wanted to know about lead-acid batteries and how to properly care for them: http://uuhome.de/william.darden/