HP is working on their batteries on every day to make them better. Recently, HP is going to expanding the recall of batteries it over a year ago for posing a fire or burn hazard. The most recall affected products were belonged to the period started from August 2007 and ended on May 2008 which includes the Compaq, Pavilion and G-Series laptops.
You can get a free new battery from HP if the bar codes and model numbers of your battery matches up with list, which is following:
Click here , from you can check more information regarding recall and validation.