Sometimes an app gets out of control and eats up your battery, even while it doesn’t seem to be active. Once, I had an iPad drained almost completely by a runaway instance of Skype. Or you may have an app that is supposed to run in the background — a synthesizer, or another music app, for example — and you forget you left it running, draining your iPhone battery.
Or perhaps you just want to see how much battery your various apps use. In any of these cases, you can open up a Settings screen that will report which apps have used how much battery, and for how long, over the past day or week. It’s a very handy screen indeed.
The iPhone battery shame-o-meter
Found in Settings>Battery, the iOS shame-o-meter lists recently used apps, ranked by how much battery they have used. You can flip between two views, showing the last 24 hours or the last seven days. On my iPhone (and my iPad, too), Safari usually tops the list, which is to be expected. It is most often followed by Overcast, the podcast-listening app, or Messages or Photos. This is all to be expected. What you should be concerned about is when an unexpected app shows up at the top of this list, especially if your battery has drained faster than usual. Then it’s time to get forensic.
See which apps drain your iPhone battery
The above screenshots show the different views available in the iOS shame-o-meter. The basic one shows the percentage used by each app. The more advanced version, accessed by tapping the little clock icon, shows how many minutes the app spent on screen, and how many running in the background.
The one to watch here is the background period. Some apps are expected to run in the background — Overcast is a good example, because it plays audio either with the screen off or while I’m doing something else with the iPhone. Apps that refresh themselves in the background are also likely to spend a higher-than-average time running in the background. Twitter apps, news-gathering RSS apps, that kind of thing.
Sometimes, though, you’ll see something awry. Just a few days ago my iPad Pro’s battery dipped to less than 50 percent in the morning, when it had been almost full the previous evening. The culprit was AudioCopy, a terrible app that developer Retronyms forces its users to use in order to get audio out of its other (excellent) music-making apps. The shame-o-meter ratted it out, and I deleted it in anger — a futile gesture, as I’ll only be forced to reinstall it again soon.
Battery drain percentage game
The percentage part of the shame-o-meter needs a bit of explaining. Say my iPhone’s battery is at 95 percent. That is, it has only used 5 percent of its full charge. If the shame-o-meter tells me Safari used 50 percent of my battery, it has only used half of that 5 percent. It hasn’t used half of my whole battery charge (as should be obvious, because the battery hasn’t been drained down to half-full).
A great iPhone battery diagnostic tool
The iPhone battery shame-o-meter is great. It’s a a really useful feature for tracking down rogue apps. I usually take a look at it once in a while, just to check up on things. It’s also the first place I look when my battery runs down faster than usual. Usually, though, the culprit for the faster-than-expected drain is “going outside,” something I do so seldom that I’m always surprised by the results of turning my screen brightness up above zero, and having to run the GPS constantly just to find the supermarket that’s only a quarter-mile from my apartment.
And if you’re looking for more tips on how to save battery life, you should head to Apple’s own official page on the subject. It offers tips not just for iPhones and iPads, but pretty much everything Apple makes with a battery in it.