The Scoop
Picture a slightly large balloon inside a tiny paper bag being blown up. In reality what’s going to happen is the balloon will continue to get filled and finally tear through the bag. The balloon will not explode, it simply increases in size.
Here’s the low down. Every time your phone is charging the current causes your battery to heat up and therefore expand a wee bit. Since you already know that the battery compartment fits the battery perfectly and there’s really no room for expansion, it simply pops out of its casing. AND THAT’S IT! This is how it is according Nokia.
Nokia has issued an Advisory that has gone out to every one of us who can get it out to you as soon as possible. There is no cause to be alarmed at all. Let me put it this way – just take a chill pill people.
The batteries in question – the BL-5C, manufactured by Matsushita Battery Industrial Co., Ltd. of Japan are quite common to most Nokia phones. You’ll find them in models like the Nokia 6270, Nokia 1100, Nokia 3100, Nokia 6230, Nokia 6600, Nokia N70, and Nokia E60. These are just a few of the more common models. If you want the complete list check out Nokia.com And Nokia is working closely with Matsushita and will be cooperating with relevant authorities to investigate this situation.
According to Nokia, even though there were around 300 million batteries like this there were only 46 million batteries that were manufactured during the period of December 2005 and November 2006. Out of that number there have been approximately 100 incidents of overheating reported globally. No serious injuries or property damage have been reported and according to Nokia’s knowledge this issue does not affect any other use of the mobile device.
Now people, please understand that the advisory that Nokia has provided is strictly for those who own Nokia phones that have the BL-5C battery that has been manufactured during the given period i.e. between December 2005 and November 2006. Other Bl-5C’s will have no problem.
Nokia's batteries do NOT explode. My best friend Laura has always had a Nokia phone...she has had about 17 different phones all together, all Nokia. Not one of those batteries has exploded..:) 
