The battery life of the new Apple Macbook Pro is tested according to a new process that started with the release of the latest Macbook Air, using testing conditions closer to real-world use than the previous procedures conducted on the recently replaced model. Because of this, the battery life claims of the old and new Macbook Pro notebooks cannot be directly compared.
Apple's battery life length claims for its latest Macbook Pro models are 7 hours across the entire 13in, 15in and 17 range — up to three hours less than the claims made by the previous Macbook Pro. The superseded version of the Macbook Pro, which was released on 14 April 2010, was rated at up to 10 hours battery life on its release due to the use of a high-capacity non-removable cell. The 10 hour rating represented the expected battery life per charge of a 13in Macbook Pro, while the 15in and 17in notebooks claimed a battery life of 8 to 9 hours.
A Google Cache record of Apple's battery life claims for the Macbook Pro describes the previously-used battery life test: "13-inch Macbook Pro testing [was] conducted by Apple in March 2010... 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%."
The same batteries are used in each model of the new Macbook Pro, with the 15in Macbook Pro retaining its 77.5 Watt-hour lithium polymer cell. The 13in Macbook Pro keeps using a 63.5 Watt-hour battery and the 17in configuration uses a 95 Watt-hour pack. An addendum on the Apple Web site for the latest Macbook Pro covers the updated testing procedures, with different wording to the earlier test: "Wireless web testing [was] conducted by Apple in February 2011... The wireless web test measures battery life by wirelessly browsing 25 popular websites with display brightness set to 50%."
Apple's new battery life testing procedure started with the release of the Macbook Air in late 2010. An addendum on Apple's product page for the Macbook Air notes the same testing procedures as those used on the most recent Macbook Pro: "The wireless productivity test measures battery life by wirelessly browsing 25 popular websites with display brightness set to 50%."