iOS 7: Stretch Your iPhone's Battery Life
UPDATE: Apple has found that the batteries in some iPhone 5 units drain too quickly. They'll replace those batteries for free. Read all about it on my post "iPhone 5 Battery Replacement Program."My iPhone 5, with iOS 7, ran out of power today. I don't know exactly when but I know it was before 6 PM. That's not good. It's never happened before, but then again I never accidentally turned on Bluetooth (because it was almost impossible to do that accidentally in previous versions of iOS) and I also never had a feature called Background App Refresh that keeps some of the iPhone's apps up to date even when the phone's not being used.
Let's talk about these things.
First, Bluetooth.
If you're not sure that you need it, you probably don't. And even if you do need it, you probably don't need it all the time, so turn Bluetooth (and its battery-sucking antenna) off when you can. iOS 7's Control Center lets you quickly and easily access your iPhone's Bluetooth on/off switch, so now you can turn it off when you don't need it (such as when you're not playing music or phone calls through your car's stereo system, or not using one of those annoying Bluetooth headsets that irritate every person you call with lousy, choppy sound). iOS 7's Control Center also lets you quickly and easily accidentally turn ON Bluetooth, so watch out for that. I think I did that today when I went to Control Center to adjust my iPhone's brightness. (Remember: swipe UP from the bottom of the screen to access Control Center.)
BONUS: actually, it's a whole lot easier to pull up the Control Center when you start your swipe below the screen. Also, you don't have to swipe up along the centerline of the iPhone-- try starting on either side of the Home button and swiping up from there. Impress your friends with your ability to pull up Control Center every time while they struggle. (Then give them the URL for this here blog.)
HISTORICAL NOTE: did you know that the Bluetooth wireless protocol was named after Danish King Harald Gormsson, who liked blueberries so much that his teeth turned blue? He was good at getting diverse peoples to communicate with each other. That's sort of what Bluetooth (the wireless protocol) was created to do, so lacking a better idea they named it Bluetooth. At least that's the story. Lucky for us he didn't like rainbow sherbet.
And Now, Background App Refresh
This certainly sounds like a nice idea: apps that need location data, or an internet feed, or some other kind of information, can update themselves even when you're not using them, so when you do use them they are already up to date. It's off by default, but the first time iOS 7 launches it asks whether you want it on or not and like a fool I said yes. (I like how they say "Turning off apps may help preserve battery life." Written by the same guys who came up with "Your mileage may vary." No kidding.)
and…
and…
and finally: 
Luckily, nicely, Apple lets us turn off background app refresh on an app-by-app basis. For now, I've thrown the switch at the top, turning off background app refresh altogether. I might turn it back on for a very few select apps but I kind of think not. I'd rather preserve the battery's life than have everything instantly up to date. If you're having trouble keeping the battery alive all day under iOS 7 see if turning off Background App Refresh makes things a little better. Settings/General/Background App Refresh.
