An official at Japan’s ministry of trade and economy said a defect is suspected in the lithium-ion battery in the iPod Nano, model number MA099J/A, according to the AP.

Battery fires are rare in iPods, but not unheard of. A search of Apple’s discussion boards turned up a similar report filed on Feb. 20, 2008 by a user named Phil under the heading “My iPOD nano Exploded” (link). It reads in full:

Is there something wrong with the battery they put on the first gen ipod nano. mine just got blown to pieces. I was just charging it on my Laptop then it suddenly sparks and it caught fire. even the clicking wheel got melted. and the back of the ipod split open.

am i the first to experience this flaw! im so disappointed with that.

What should i do?

if you wanna see the pic go to – http://www.flickr.com/photos/23960698@N02/

The photographs show a badly charred black iPod nano, model No. A1137.

Lithium ion batteries have caught fire in Apple notebook computers, as well as laptops made by Sony (SNE), Dell (DELL), Lenovo and other manufacturers.

In the iPod line, only the nano seems to be having similar problems. In October an Atlanta airport worker claimed his iPod “nana” caught fire in his pocket, although TV reports of “chest-high flames” don’t seem credible. (link) Last April, an Australian reported in an Engadget forum that his nano exploded with a force that sent it flying to the floor, where it sparked and smoked until he unplugged it. (link)

There are no reports of other iPod models catching fire in Apple’s discussion boards.

Apple introduced the first generation iPod nano in Sept. 2005 and sold its first million in 17 days. It was discontinued in Sept. 2006.

It’s not clear why the problems are surfacing now, or why Apple waited nearly two months to report the Japanese incident to the government, as required by law. Japan’s ministry of trade and economy has “strongly warned” Apple and instructed it to investigate the cause.