Testing tablets can sometimes be a time-consuming endeavor, especially when a tablet like the iPad 2 can last for well over 10 hours on one charge while running video. To make matters worse, the iPad 2 has no loop option for video. This means that when running a movie like "Toy Story 3" to drain the battery, every 1 hour and 40 minutes, I am required to be standing in front of this thing to restart the movie.
I have to basically plan my entire day around testing: when I take lunch, bathroom visits, meetings, Starcraft II matches, etc. It also means I have to be at work for more than 12 hours on the days the iPad is battery-tested.
Being able to loop the video until the battery dies would be the obvious, desired solution, but unfortunately, there is no way (that I know of) to loop iTunes-downloaded video on the iPad. There are a few apps out there that claim to loop video, but I had little luck with them. Sure, one was able to loop video recorded by the iPad 2, but again, not with video downloaded from iTunes.
Below you'll find new results for video battery life of the iPad 2 and gaming battery life on all three tablets featured here. Also, if you're privy to a workaround that allows iTunes downloaded video to loop on the iPad 2, do not hesitate to pass it along. You'll save me from some very long workdays.
|Tablet name||Video battery life (in hours)||Gaming battery life (in hours)||Web site load time
(in seconds; lower is better)
|Maximum brightness (in cd/m2)||Default brightness (in cd/m2)||Contrast ratio|
|Apple iPad 2||11.9||8.3||5||432||176||939:1|
How we test tablets
In the CNET Labs, we currently run three different tests to evaluate the performance of non-Windows tablets.
We evaluated battery life in two ways. First, by continually running a movie file on the tablet until its battery died and also by running a game on the tablet until the battery died.
We set each tablet to Airplane mode and adjusted its respective brightnesses to 150 candelas per square meter (cd/M2), or as close to that number as is possible.
With movies, for the iPad, we run the iPad version of "Toy Story 3." For Android tablets, a 720p version of "Toy Story 3" was run. The reason we chose 720p for Android was that not every tablet can run 1080p video just yet, and we wanted to make sure we tested Android tablets under the same methodology.
On the iPad, we ran the movie through its iPod app; for Android, we used the movie player mVideoPlayer, as it provides a much needed repeat video function that not all native Android movie players include.
For gaming, we used Dungeon Defenders First Wave. We started the game, kept the default visual settings, walked our character over near the fireplace, and let it sit idle until the battery died.
We understand that this is different from actually playing and interacting with a game. While playing a game, the processor and memory would be accessed more frequently, likely increasing its power draw. However, the impetus for this test was our desire to determine what kind of difference gaming graphics would have on battery life versus watching a movie.
We used GiantBomb.com as our Web site of choice, as it doesn't use Flash or have many dynamic elements. Each tablet was connected to the same closed network with no other devices on it, with the router about 5 feet away. The test began the moment we pressed Enter, with the end of the test signified by the disappearance of the browser's blue progress bar. We measured speed in seconds, with a lower number indicating faster performance.
We used the latest version of iOS for the iPad, and the Xoom is, of course, using Honeycomb, with all other Android tablets using Android OS 2.2.
Contrast ratio and brightness
We also tested the maximum brightness, default brightness, and contrast ratio for each tablet. We conducted these tests using the Minolta CA-210 display color analyzer. With each screen at full luminosity, we placed the sensor in the middle of the screen. We used a completely white screen to test the brightness and a completely black screen to test the black level. We then divided the maximum brightness by the maximum black level to get the contrast ratio.
The iPad 2 battery lasted only a little less than the iPad, but their duration was equal in the gaming battery test. Both iPads lasted longer than the Xoom in gaming, which is likely to translate to users being able to game on their iPads longer than on their Xooms, but not too much longer. Look for more tablet tests later this week.