Anirban Bhadra, I would start off with a new battery. It is most likely that it is at the end of its lifespan. Of course, there is always the chance that something else (i.e charging IC, etc) is not working right, but start with the cheaper and easier parts first. Here is [http://www.ifixit.com/Device/iPod_Shuffle_2nd_Generation#guideList|the guide] and the battery is available at places [http://www.amazon.com/Replacement-Battery-Tools-iPod-Shuffle/dp/B004TJHUGU|like this.] Hope this helps, good luck