Nokia is offering to replace 46 million batteries made by another company for use in its mobile phones because of a risk of overheating.
The faulty batteries were manufactured by Japan's Matsushita Battery Industrial Co. Ltd. and sold in a wide range of Nokia phones, from its low-end 1100 family of products to its pricier N91 and E60 devices.
Nokia said that in "very rare cases" a short circuit can cause the Nokia-branded BL-5C batteries to overheat while they are being recharged. It said it knows of about 100 incidents so far and that no serious injuries or property damage have been reported.
The overheating can cause the battery to "pop out" of the phone while it's being recharged, says Nokia spokeswoman Marianne Holmlund. She says there was no risk of fire, although it was unclear what caused the minor incidents reported.
"It may be that the device left a small burn on a shelf while it was recharging, it's hard to say for sure," said John Devlin, research director for mobile technologies with IMS Research in the U.K.
People concerned about the problem can get their batteries replaced for free, Nokia said. It set up a Web page that lists the phone models and describes how customers can check if their battery is affected.
The Finnish phone maker has several suppliers for its BL-5C batteries and doesn't expect any shortages, Holmlund says. The suppliers have made about 300 million BL-5Cs altogether, Nokia said.
The problem exists only with Matsushita batteries manufactured between December 2005 and November 2006, and the phones would have been sold worldwide during roughly the same period, Holmlund says.
Nokia reported selling 347 million phones in 2006, making 46 million a significant proportion of its annual sales. "It is about 10 percent of all the phones sold, but we are talking about 100 incidents, which is only a tiny proportion," Holmlund says.
Nokia expects Matsushita to bear "certain financial responsibilities" for the replacement program, she says. Peter Weber, a spokesman for Matsushita in Europe, says the financial terms are being negotiated now between the companies.
The recall could be expensive if all 46 million customers decided to replace their batteries. But typically in such cases only a small proportion of customers bother to return their products, Devlin noted.
"I don't see this having a lasting affect for Nokia, just because it seems to be battery issue," he says. "They're offering to replace the batteries, so I think they're taking the necessary steps."
It's the first time Nokia has had to offer such a replacement program, Holmlund says.
Such problems in phones normally arise because of counterfeit batteries, making this case "a little unusual," Devlin says.
The problem is unlikely to affect other makes of cell phone since the batteries were designed especially for Nokia, Weber of Matsishita says. Cell phone batteries are typically designed and manufactured for a particular phone maker, Holmlund confirmed.
It's only the latest incident involving rechargeable Lithium ion batteries used in portable electronics products. Late last year laptop makers including Sony, Toshiba and Dell offered to replace a total of eight million laptop batteries because of a manufacturing defect in Sony-made batteries that left them vulnerable to short-circuiting and catching fire.
Matsushita Electric Industrial Co. Ltd. has said it is developing a new type of lithium-ion battery that won't overheat even if a short circuit occurs.
Nokia said it will work with Matsushita and the "relevant authorities" to investigate the problem. A picture of the BL-5C is here.