Windows 7 Laptop battery meter question?

Today I noticed that my laptop's battery meter will not go down. It says that it is at 100% charge and has said this for about an hour of usage while unplugged. Clearly, the battery is not fully charged. Also, when I turn the laptop on, it tells me that the battery capacity is below very low and that I should get a new battery. It also turns off on me after I use it for a long time (probably when the battery needs charging but I do not know because it does not warn me that the battery is low). However, the battery life still seems okay. In the power settings it has the notification enabled though. My laptop is a windows 7. What is wrong with my computer, and can I do anything to fix this issue? Thanks