my computer battery shows x

Welcome to the Apple Support Communities

It shows that your Mac doesn't detect the battery. The first thing you should try is to reset the SMC > http://support.apple.com/kb/HT3964 After resetting the SMC, OS X should detect the battery again.

If OS X doesn't detect the battery, it may be a hardware problem, so take the Mac to an Apple Store to get it repaired

Contact Apple at 1800 692-7753 and give the computer serial number. They will be able to confirm the age of the battery by the purchase date, and will tell you the life expectancy of such batteries.

If you feel the battery is defective, tell that to them. They may be able to confirm this by asking for some data from the computer.

Otherwise taking the computer to your local apple store, they can do the same as well.

Batteries are "consumable" products, so they do have a life expectancy and cycle counts. If it is beyond it's life expectancy, they will be able to confirm this as well.

It probably needs to be replaced. System Information>Hardware>Power>Battery Information. Post your MBP of this image from mine for evaluation:

Ciao.