For the 13-inch MacBook Pro: Testing conducted by Apple in May 2009 using preproduction 2.53GHz Intel Core 2 Duobased 13-inch MacBook Pro units. For the 15-inch MacBook Pro: Testing conducted by Apple in May 2009 using preproduction 2.8GHz Intel Core 2 Duobased MacBook Pro units with a Better Battery Life setting. For the 17-inch MacBook Pro: Testing conducted by Apple in May 2009 using preproduction 2.8GHz Intel Core 2 Duobased MacBook Pro units with a Better Battery Life setting. Battery life depends on configuration and use. See www.apple.com/batteries for more information. The wireless productivity test measures battery life by wirelessly browsing various websites and editing text in a word processing document with display brightness set to 50%.
What is the 2009 MBP battery has to do with 2011 MBP one?
http://store.apple.com/au/browse/home/shop_mac/family/macbook_pro?mco=MTM3NjU5MzU (number 2 at bottom)