In the military’s DEFCON ratings system, red is a serious color. That’s DEFCON 2. That’s imminent nuclear war. You know what DEFCON 1 is? Bombs dropping. Civilization as we know it ending. We might never even see DEFCON 1 as our eyes melt into radioactive goop, meaning that in a sense, DEFCON 2 is about as bad as it gets.
So it’s a little bit strange that every time an iPhone drops below 20% power, the battery indicator doesn’t give a subtle nudge to recharge. It turns red—the color of imminent danger—the color of DEFCON 2, the Red Cross, emergency alerts, blood, fire trucks, and even some actual flames.
Of course, none of us throw our low-powered phones away from our person like a live grenade. We can recognize that this moment isn’t a real emergency, but as the battery indicator turns red, the icon does signal just a bit of tension in your chest, doesn’t it? Breathing in a little bit less than you should, you wonder, "Did I...did I forget my charger at work?"
In this regard, a red battery indicator is a poorly designed solution for a mobile phone. This gadget belongs to us. We are its master. It's on this Earth to make us happy. Yet through that red color, we get negative reinforcement for using 80% of its capacity over any given time. We become schoolchildren as that alert sits like a failed grade on the top of an iPhone’s home screen. And in fact, this failed grade phenomenon has been found to be quite powerful in lab experiments: Those subjected to the tiniest scrap of red during cognitive tests do not perform as well—meaning a red battery indicator could, theoretically, cause distress that makes it more difficult to find your charger.
Practically speaking, 20% of one’s battery is still quite a bit. For the iPhone 5s, 20% is by no means a ticking time bomb. The battery still has two hours of talk time or video, and a full 10 hours of MP3 playback. The iPhone is basically saying, "WARNING!!! YOU ONLY HAVE POWER FOR ONE MORE FULL-LENGTH MOVIE BEFORE YOU HAVE TO PLUG BACK IN! WHERE WILL YOU BE THEN?? CAN YOU MAKE ACCOMMODATIONS OVER THE NEXT TWO HOURS?? IF NOT, MAYBE JUST RE-WATCH AN EPISODE OF THE OFFICE INSTEAD. YOU KNOW, ONE WHERE JIM AND PAM ARE STILL JUST MAKING FURTIVE GLANCES."
Interestingly enough, Apple may be a bit behind the competition in this regard. The new Moto X and Nexus 5—which run Android—don't turn red upon a low battery, but an eye-catching orange. The effect grabs your attention without the indication that something is wrong. It’s a subtle UI tweak that falls right in line with Google’s modern Android design principles, ensuring that users always know that when things go wrong, "It’s not my fault."
Meanwhile, Windows Phone 8 opts for no colors at all, and running down your battery actually offers positive reinforcement. The battery indicator develops a snuggable heart when it enters its Battery Saver mode (congrats obsessive phone user, you’ve found love!). Though it should be noted that while Windows Phone 8 doesn’t adopt red, one user reports to us that his HTC Windows phone deploys a blinking red LED in a red icon’s stead!
So what should Apple do with iOS? Just turn the red back to white. We can still see the precise percentage of battery we have left, and we're perfectly capable of knowing 5% is a problem. Or better still? Make that battery icon tappable, and do the math for users breaking down just how many talk, browsing, and MP3 minutes they have remaining before they should recharge. At the end of the day, there's no one right path that Apple must take. But a DEFCON battery indicator is certainly the wrong one.