iPads and iPhones make great travel companions. These devices offer quick access to step-by-step directions, public transit information, email on the go, and restaurant recommendations--and as a result, they tend to spend more time in our hands than in our pockets or bags. But what happens when your traveling pal's batteries begin to run low and you're nowhere near a charger? Well, they say knowledge is power, so lets get charged up by separating fact from fiction on the subject of how to save iOS's devices' battery life.
To get to the truth about nine commonly held ideas on battery power conservation, the Macworld Lab grabbed a fourth-generation iPad and an iPhone 5 and started charging, draining, and timing different tasks and scenarios. What we discovered can help you and your iOS device get through your next trip without running out of juice.
1. Screen brightness affects battery life.'
Heck yeah, it does. Screen brightness was the single most significant contributor to battery depletion that we found. At full brightness and in Airplane mode, our iPhone 5 lasted 6 hours, 21 minutes while playing 720p video from a movie file. When we set the screen to half brightness, the phone lasted 9 hours, 48 minutes--that's 4 hours, 27 minutes longer than the battery lasted with the screen set to full brightness. In similar video tests, our iPad's battery lasted twice as long when set to half brightness as when set to full. To change your screen's brightness, tap Settings, tap Brightness & Wallpaper, and then adjust the Brightness slider.
2. AirPlay streaming from my device to a TV will quickly drain my battery.'
You might think that accessing a movie file on your iOS device's internal flash storage and then streaming it to an AirPlay devicetakes a toll on battery life, but it didn't in our tests. Our iPad streamed high-definition video to an AppleTV-connected Sony Bravia for a whopping 13 hours, 45 minutes. And after all that time, it still wasn't close to running out of steam: When we stopped the test (to, you know, go home and see our families and stuff), the iPad's battery still had 82 percent of its capacity.
3. Using iTunes Home Sharing to stream video from a Mac to my iOS device drains my battery faster than watching a movie already on my iPad.'
Reversing the direction of the signal, playing a movie from a computer on our Wi-Fi network on the iPad took much more energy, mainly due to the demands of the iPad screen. Set to full brightness, the iPad managed to play 5 hours, 34 minutes of video--50 minutes less than it delivered when the video was playing from a file stored on the device itself.
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