Apple has initiated a worldwide recall for some 15-inch MacBook Pro batteries [1] that were sold between February 2006 and May 2006, due to lack of performance (and not due to safety risks, such as a string of recent Dell laptops that have caught fire [2]). To identify batteries covered under the program, look on the underside of the battery for model number A1175 and a 12-digit serial number that ends with U7SA, U7SB, or U7SC.

[1]: https://support.apple.com/macbookpro15/batteryexchange/
[2]: http://www.gizmodo.com/gadgets/dell/another-dell-laptop-goes-kabloom-190579.php