Need a Laptop Battery

My laptop doesn't feel like a laptop because I have to have it plugged in to work. The battery light comes on saying there is no power even if it has been plugged in all night. The lap top is only a year old. Shouldn't a battery last longer than that? It's so annoying when I just want to sit comfortably on the couch or on my bed, and it gets so cumbersome having it plugged in. Feels like I have a desktop right now.