One of the inescapable truths of modern technology is its penchant for regularly sucking from the national grid, like some kind of crazed electronic vampire. You might consider your iPhone the most amazing technology in the world, or your iPad some kind of magic bestowed on you by unicorns (if so, possibly lay off the sauce), but they're little more than metal-and-glass slabs when out of juice.
For the most part, this won't be a problem, but occasionally it will be: when you're away for the weekend and forget your charging cable; during a power-cut of indeterminate time; or just when pootling along on a slow train, trying to coax your device into surviving what would otherwise be a long and boring journey home.
Depending on your circumstances, there are some tricks to keeping your iPhone, iPad or iPod touch alive for crucial extra minutes or even hours. And almost none of them involve sacrificing Android devices on an Apple-shaped altar.
OK, so your iPhone won't really say this, but it'll probably mutter something similar under its breath.
1. Turn down the brightness
That Retina iPad you're lugging about packs more pixels than an iMac. Even an iPhone's pixel count rivals that of a MacBook Air. It should therefore come as no surprise the screen is your iOS device's primary power drain. A quick fix is to turn down brightness using the slider in Control Center, accessed by swiping up from the bottom of the display. A better option is to open the Settings app, access Wallpapers & Brightness, turn off Auto-Brightness and drag the brightness slider as far left as possible, but with a setting that still leaves your device usable.
2. Disable Wi-Fi, Bluetooth and 3G
If you're not using mobile and wireless protocols, turn them off, because otherwise they're just draining your battery. Wi-Fi and Bluetooth can be disabled from Control Center. 3G can be disabled in the Cellular section of the Settings app. If you temporarily don't need any communications at all, turn on Airplane Mode (tap the airplane icon in Control Center) to disable all of these things at once.
3. Kill services that regularly poll data
Plenty of applications and services work away in the background, pulling down data. When your device has plenty of power, this saves you time; but when your device is running on fumes, it's best to only grab data when you really need it. In Settings, access 'Mail, Contacts, Calendars', and turn off Push under Fetch New Data. Under iCloud, temporarily turn off anything you're not using. Also, in Privacy > Location Services, disable the service for individual apps or even globally.
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