Nokia has warned that some of its BL-5C batteries could suffer a short circuit while charging, causing the unit to overheat and bulge.

The handset giant has several suppliers which have collectively produced more than 300 million BL-5C batteries.

However, the problem applies only to the 46 million batteries supplied by Japanese manufacturer Matsushita Battery Industrial between December 2005 and November 2006. The batteries are used in around 46 Nokia handsets.

There have been about 100 incidents of overheating reported globally, and no serious injuries or property damage have been reported by Nokia.

The overheating can cause affected batteries to bulge and possibly dislodge the phone's battery cover.

Mark Squires, communications director at Nokia, told vnunet.com that the problem has surfaced now because it requires over 200 charging cycles before the issue manifests itself.

Squires added that the rate of incidence is low and that the problem does not damage users' phones.

Nokia has set up a Product Advisory website for customers concerned that they may be using one of the potentially faulty batteries.

Affected customers can fill in an online form to have a replacement battery sent to them and return the old battery for recycling.