Batteries to Be Replaced

Over 46 million BL-5C batteries powering Nokia cellular phones will be replaced for free, according to a Nokia advisory posted on its Web site.

The batteries, manufactured by the Japanese company, Matsushita Electric, were found to overheat. These batteries were produced between December 2005 and November 2006.

New batteries may not immediately show signs of overheating. The problem can happen after recharging the battery a few hundred times. Nokia said there had been about 100 incidents of overheating reported globally, but there were as yet no indications of damage or serious injuries.

The US Consumer Product Safety Commission (CPSC) is stepping in to investigate the problem. The CPSC warns of possible short circuits occurring if batteries are dropped at a certain angle, placed under great pressure, or left inside a car exposed to the heat on a summer day. When a short circuit occurs (however rarely that may happen), a fire or an explosion could result.

Nokia’s offer to replace the lithium-ion batteries is the latest in a series of recalls involving more than 10 million batteries for laptop computers in the last one-and-a-half years. The recalls covered many well-known computer brands.

Experts say, however, that lithium-ion batteries remain the safest power source for the myriad portable electronic devices in use today. Lithium-ion batteries are used to power cellphones, laptops, music players and other devices. They are preferred for their large energy output relative to weight and their ability to retain their charge much longer than other batteries.

However, when small dust particles remain in the battery, it can overheat and, more rarely, catch fire. The dust particles pierce an internal part that partitions the battery into sectors, causing the overheating. Piercing or dropping the battery or exposing it too long to heat can lead to the piercing phenomenon.

Nokia’s move would be the biggest lithium-ion battery replacement ever, dwarfing previous battery recalls over the past year by several makers of laptop computers. Until Nokia initiated the call for replacement, most battery problems have concerned those in laptops. The reason for that is laptop batteries are used for longer times than cellphone batteries which are on “standby” mode most of the time — except for some people who can’t seem to stop talking on their cellphones.