Battery life is a key aspect of a laptop, especially to travelers who don't have easy access to a power outlet. To test the new MacBook and MacBook Pro for battery life, we performed a battery-drain test by watching a movie clip ripped from a DVD to the laptop's hard drive. We played the movie at full screen, with the screen brightness set to maximum to simulate the low lighting of an airplane cabin. If the movie finished and the battery still had power, we played the movie again, until the battery drained.
The new 2.4GHz and 2.0GHz Core 2 Duo MacBooks have comparable battery capacities, each lasting a little over 2 hours, 30 minutes. That's plenty long for most movies, though if you're watching "The Lord of the Rings: The Fellowship of the Ring"you might miss the end. However, these results indicate that the new MacBook has about 22 to 24 minutes shorter battery life than the old white plastic 2.1GHz Core 2 Duo MacBook, which finished our test at 2 hours, 57 minutes.
Since the two new MacBook Pro models each have a pair of graphics cards, we ran the battery life test using each one, resulting two battery life scores for each MacBook Pro. At the MacBook unveiling last week, Steve Jobs boasted that with the MacBook Pro's Nvidia GeForce 9400M graphics card enabled you could achieve up to 5 hours of battery life, and 4 hours with the GeForce 9600M (the same graphics subsystem in the new MacBook). We're guessing that he didn't expect users to replicate those times while playing DVDs. Instead, those projected times likely are the results of tests that were not as demanding on the computer, like word-processing or Web browsing.
While watching a movie, you can expect battery life of roughly half of those projected times. Using the 9600M GT graphics card, the 2.53GHz MacBook Pro lasted 2 hours, 12 minutes, while the 2.4GHz MacBook Pro lasted 2 hours, 18 minutes. You'll barely be able to watch an entire movie in that amount of time. That said, you really don't need the better performance of the 9600M GT while watching a movie.
Movies run just as smooth on the 9400M, and you'll get longer battery life. Unfortunately, when using the 9400M, the battery life for either MacBook Pro model did not improve significantly. The 2.53GHz MacBook Pro gained 17 minutes, while the 2.4GHz MacBook Pro lasted 13 minutes longer. Interestingly, the 9400M times between the MacBook Pro models and the MacBooks are similar.
Comparing the MacBook Pro's 9400M battery life with the previous MacBook Pro, and the older MacBook Pro comes out ahead by 15 percent--the older MacBook Pro's battery lasted close to 3 hours.
While the new Macbooks and Macbook Pros do not have the battery capacity that many users demand for a long distance travel, they still should get your through most feature length movies. These tests are only one kind of battery test and do not in any way indicate the expected battery life for while doing everyday tasks, like email, Web browsing, writing text, etc.
[Chris Holt is a Macworld assistant editor.]