My battery after two years in used, is getting slow and does not faction.

To whom it may concern, my battery after two years in used, is getting slow and does not faction enough. What can I do? I also have windows 7, pc Gateway. My mistake is that I used to take it off (the battery) and worked only by cable. Is there anything to do? Thank you in advance.

You can replace the battery without having to replace the entire laptop.

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