Nokia: Third-party batteries may melt your phone

Mobile phone maker Nokia warned on Friday that a growing number of its handsets are being damaged by badly made or counterfeit batteries from other companies.

The number of phones destroyed by so-called third-party batteries, sold by street vendors or on the web, have risen enough since December to prompt a warning from Nokia.

The batteries usually don't have circuitry to shut down the power source once it begins overheating, a company spokesman said. Enough heat can be generated to melt a phone's plastic casing and the circuits inside, he said.

He added: "People really shouldn't use anything but a Nokia-made battery inside any of our phones. If a third-party battery is made improperly and destroys a phones, it's not going to be covered under warranty."

Nokia handset owners in Asia, Africa and Europe have reported problems. The handset maker did not name specific battery makers to watch out for.

Nokia appears to be acting out of genuine concern, rather than using the warning as a scare tactic to keep customers from buying phone accessories made by other companies.

Mobile phone manufacturer Motorola is unaware of any increase in its phones being destroyed by third-party batteries. But the problem remains a persistent one.

A spokesman for the company said: "It's fair to say that it happens with sufficient frequency."