According to Yahoo News Japan warned Apple iPod nano users of a potential fire risk after two new instances in which the portable music players overheated were reported in August.
The Japan economy, trade and industry ministry received two new reports of minor fires in Tokyo caused by overheating iPod nanos, said ministry official Hiroyuki Yoshitsune. There were no injuries and the cause is still unclear, he said.
There have been earlier reports of iPod nano fires, and Japan had already launched an investigation in March after another Apple iPod nano sent out sparks. According to the ministry, Apple was notified of a total of 14 similar cases in Japan. Out of those, two users suffered minor burning.
"Users need to be careful about overheating of the machines," the ministry said in a statement, warning that particular care is needed when recharging the iPods. "Our ministry told Apple to improve its technological development and probe the cause of the incidents so that similar incidents do not happen again”.
The ministry said the incidents were caused by four models -- MA004J/A, MA005J/A, MA099J/A and MA107J/A -- of which 1.81 million units were sold between September 2005 and September 2006 in Japan. All of the iPod nanos in question are older-generation iPod nanos. The incident, involving the MA099J/A model, occurred on January 8 in Kanagawa prefecture near Tokyo. Apple reported the matter to the ministry on March 7. The cause of the sparking, it is believed, is tied to the lithium-ion batteries used in the iPod nano.
Following the reports out of Japan, Apple issued the following statement:
Apple today responded to statements reported by Japan’s METI regarding batteries in the first-generation iPod nanos. Apple has determined that in very rare cases, batteries in first-generation iPod nanos sold between Sept. 2005 and Dec. 2006 can overheat, causing failure and deformation of the iPod nano. Apple has received very few reports of such incidents (less than 0.001 percent of first-generation iPod nano units), which have been traced back to a single battery supplier. There have been no reports of serious injuries or property damage, and no reports of incidents for any other iPod nano model.
Any first-generation iPod nano customers who have experienced their battery overheating should contact AppleCare for a replacement. Any other customers who have concerns about their first-generation iPod nano battery should also contact AppleCare.
Lithium ion batteries, which Apple uses for iPods Nanos, are common in consumer electronics. In the past major battery makers, such as Sony have occasionally been forced to recall large numbers of lithium ion batteries after reports of overheating and fire.
quote: I'd like to think I invented the term iFire
quote: I've never noticed any heat related issues with my 80GB 5G iPod, however.
quote: The exact reaction that generates the electrons varies, depending on the type of battery. In a lithium-ion battery, you'll find pressurized containers that house a coil of metal and a flammable, lithium-containing liquid. The manufacturing process creates tiny pieces of metal that float in the liquid. Manufacturers can't completely prevent these metal fragments, but good manufacturing techniques limit their size and number. The cells of a lithium-ion battery also contain separators that keep the anodes and cathodes, or positive and negative poles, from touching each other.
quote: If the battery gets hot through use or recharging, the pieces of metal can move around, much like grains of rice in a pot of water. If a piece of metal gets too close to the separator, it can puncture the separator and cause a short circuit. There are a few possible scenarios for what can go wrong in the case of a short circuit:* If it creates a spark, the flammable liquid can ignite, causing a fire.* If it causes the temperature inside the battery to rise rapidly, the battery can explode due to the increased pressure.* If it causes the temperature to rise slowly, the battery can melt, and the liquid inside can leak out.