Dell has issued a massive recall of batteries for a number of it's laptops, the story was broken by CNET:
The Official Dell Site that has opened to deal with the recall is:
https://www.dellbatteryprogram.com/Default.aspx (It's a secure website)
The page on this site where you can enter a Battery Serial Number (PPID) to see if this recall involves your laptop:
If your battery is involved in this recall, once you enter the PPID, you will get further information on getting a new battery, free in all respects, courtesy of Dell.