The move follows complaints that the affected batteries were overheating because of a short circuit while charging, causing the battery to expand and dislodge from its place and making the phone go off. Globally, there have been around 100 incidents of overheating while people were charging their phones, but no serious injuries have been reported, the company said.

How do you check out if your phone has a defective battery?
Go to nokia.com. There is a line right on top in green: ``More information concerning battery replacement.'' Click on it. Scroll to the bottom of the next page titled, `Product Advisory'. There is a slot to enter the 26-digit identification number on the back of the battery. Enter it and you will be told if the battery requires replacement. Or, dial customer helpline (080-30303838) to find out if your battery needs replacement.

While the chances are high of your phone running on a defective battery, the company said that of the BL-5C batteries, only 46 million manufactured by Japan's Matsushita in that one-year period needed to be replaced. The other batteries are fine.

In case the batttery needs replacement, you have to fill up an online form. A Nokia spokesperson said it will only take courier time for replacement. You will get an empty packet with the new battery to return the defective one to the company.