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Matsushita-made batteries could bust open Nokia cell phones

Lithium-ion batteries are giving more than just laptop makers constant headaches. Cell phone goliath Nokia today issued a product advisory for the Nokia-branded BL-5C battery warning consumers that the device could potentially experience overheating initiated by a short circuit while charging, causing the battery to dislodge.

As the cells in mobile phone batteries are smaller than those found in laptops, the risks are the same. Nokia told Engadget that the batteries will “overheat, expand, and pop out of the phone (due to the expansion of the battery).” The Finnish company said that no serious injuries or property damage have been reported.

Nokia has several suppliers for BL-5C batteries who have collectively produced more than 300 million BL-5C batteries. The estimated 46 million BL-5C batteries at fault are manufactured by Matsushita Battery Industrial Co., Ltd. of Japan between December 2005 and November 2006, from which there have been approximately 100 incidents of overheating reported globally. Nokia said that is working closely with Matsushita and will be cooperating with relevant authorities to investigate this situation.

Nokia is offering that all customers with affected BL-5C devices a replacement BL-5C battery free of charge. For a full list of affected phones and a form to check via product identification number, see Nokia’s website.

Battery recalls are a familiar thing for laptop makers, as over 10 million lithium ion laptop batteries have been recalled worldwide since last year. A long list of computer manufacturers has felt the effects of the defective batteries, including Sony, Dell, Apple, Lenovo and Toshiba.

Interestingly, Matsushita said in late 2006 that was mass producing improved lithium ion battery technology that safeguards against overheating. It is unclear if the BL-5C batteries incorporate this anti-overheating technology.

“When any supplier has a problem, it creates concern for the technology itself. The challenge that we must meet is to reassure the public that Lithium-ion batteries are safe,” said Michael Buckner, senior manager for Panasonic's Energy Solutions Lab, in an interview with DailyTech. “Safety has always been the number one priority at Panasonic. The incidents last year just reconfirmed that we need to maintain safety first in our designs.”



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RE: omh another mountain out of a mole hill
By omnicronx on 8/14/2007 1:11:44 PM , Rating: 2
speak for yourself, generally yes, always no. I always charge my phone beside my computer when i get home, and talk on it while doing so as i don't like to screw with the recharge cycle. Weirdly enough, my phone battery exhibits the symptoms that the warning pertains too, so it could have happened to me ;)

(something gives me a feeling charging it like i did, probably killed it heh)


RE: omh another mountain out of a mole hill
By TomZ on 8/14/2007 1:55:42 PM , Rating: 2
There should be nothing (reasonable) that you can do to cause the battery to do that, and there is no reason to worry about messing up a recharge cycle, unless the phone and/or battery are defective or improperly designed.


RE: omh another mountain out of a mole hill
By omnicronx on 8/14/2007 3:34:29 PM , Rating: 2
quote:
there is no reason to worry about messing up a recharge cycle, unless the phone and/or battery are defective or improperly designed.
I know, i am just weary of the old original lithium-ion days.. of course those days were over in the early 90's but watcha gonna do ;)

off hand tomz, do you know if the 3 charge/deplete rule when you first use your device for lithium batteries still exists?


By TomZ on 8/14/2007 4:21:43 PM , Rating: 2
I'm not aware of that rule. Deep discharge of Li-ion cells is generally a bad thing. Maybe somebody else knows more?


By DragonMaster0 on 8/14/2007 8:39:18 PM , Rating: 1
But again, if it's due to overheating batteries, you couldn't even touch the phone, unless you're really holding your phone with oven mitts??? ;-)

The batteries are the problem. Pretty much every recent Li-ion batteries contain small controllers to prevent overvoltage and monitor how much battery life is left. That's because Li-ion is really sensitive to out-of-specs uses unlike NiCd/NiMH/Lead-acid. If the circuit is defective, it will cause trouble. Matsushita did a good thing to finally start to think about sensing the battery temperature as well, this is a thing previous battery packs didn't monitor.

The BL-5C was probably designed before Matsushita started thinking about overheat protection, therefore it probably doesn't have the feature since the battery is supposed to have the same stuff inside no matter who manufactured it.


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