Battery life is of utmost importance especially in new smartphones that come with 4G LTE support – LTE is already a battery hog, and there’s only so much space inside a smartphone that can be used for the battery, but it's not just LTE that consumes plenty of juice. You’d think most app developers would try to make their apps as efficient as possible when it comes to smartphone and tablet power usage. But apparently that’s not the case, and there are plenty of Android apps that aren’t as efficient as one would think.
A recent study conducted by researchers from the Purdue University shows that many Android developers mishandle certain Android APIs, which prevent the phone from going into sleep mode until the app completes the action it's supposed to perform periodically in the background, and thus these apps become silent battery killers.
Various apps need to be awake at certain times in order to perform certain tasks, but once that happens they should be automatically turned off in order for the smartphone to get back into sleep mode. Y. Charlie Hu, a Purdue University professor of electrical and computer engineering explains:
[…] smartphones are always in a sleep mode, by default. When there are no active user interactions such as screen touches, every component, including the central processor, stays off unless an app instructs the operating system to keep it on.
Researchers found that out of the 187 Android applications that used “Android’s explicit power control APIs, called ‘wakelocks,’” 42 of them, or around 22%, had bugs in the wakelock code which prevented them to engage the sleep mode again after accomplishing their interactive tasks. The report doesn’t mention the actual names of the apps that were found to be “battery killers” but researchers confirmed that such battery issue affect other mobile operating systems not just Android, even though their study focuses only on Android apps.
All this happens without users being aware of what’s going on with their smartphones that appear to be turned off, so next time your battery dies unexpectedly you may want to check whether the apps you’re using in the background are efficient enough for your device. In fact, we have already shown you an application that analyzes the activity of your smartphone and could help you determine ways to improve battery life on your Android device.