Although I never own an iPhone, I have the impression that in terms of gaming, video playback and internet browsing those iOS devices always have better battery life than most Android phones, if not all. This has changed a bit since the release of LG G2, which has unbelievable battery life. For the first time, an Android flagship outlasts iPhone for comparable performance. A year later, Samsung Galaxy S5 and HTC M8 followed suite and beat iPhone series in battery longevity.
However if you look into the matter a little bit deeper, you will find that those three Android flagships all have one thing in common, big batteries. Although they all come with large screens too, the battery capacities are much higher than that of iPhone. For example, LG G2 has a 5.2′ screen that is 1.68 times bigger than in iPhone. However the screen area of G2 more than doubles iPhone 5/5s’s! If Android has something to learn from iPhone, battery life is surely among one of them.
In this article, I will try to explore where iPhone excels Android devices in battery life both in terms of hardware and software.
I will begin with screen since display is the biggest consumer of battery juice in almost all Modern Smartphone. There are three things that could impact a mobile device’s battery life, size, display type and resolution.
As we all know, iPhones all have small screens. iPhones used to have a 3.5 inch screen, and this did not change until the release of iPhone 5, which saw a small increase to 4′. However that’s still a way too small screen compared to its Android counterparts. Take Galaxy S4 as example, it has a huge 5′ screen.
In addition to small screen size, iPhones have lower resolution as well. Even though iPhone 4 is the first to sport a retina screen, Android phones are already packing full HD and now even 2K displays. The much higher resolution puts a huge strain on battery since it’s a huge workload on GPU as well.
Aside from screen size and resolution, display type matters much too. Many people may not realize that, but the great display on iPhone also helps save battery juice. While Android devices still pack a-Si display, iPhone 4s already used IGZO display, which is much more power efficient. According to DisplayMate, the iPad Air’s use of IGZO reduces the display’s power consumption by astoundingly 57% over iPad 4. Considering display uses over 50% power, this alone could mean huge power savings. Apple later adopted LTPS display on iPhone 5, which further cuts the power consumption by 30%.
CPU and GPU
It’s well known that iPhones have a powerful yet quite power efficient GPU unit. However it’s less known that they have a strong CPU as well. Android absolutely leads the core race, but Apple holds the single-threaded performance lead for a long time now.
Take a look at Anandtech’s benchmark and you will realize that. The A7 chip in the iPhone 5s not only outperforms Qualcomm S800, it’s also much more power efficient. This is self-explanatory as A7 only has two cores running at max 1.3GHz yet S800 has quad cores with a clock speed up to 2.5GHz. To push up frequency you have to push up voltage, so it’s only natural for non-A7 chips to consume more power for comparable performance.
Of course ARMv8 architecture also helps. Many people are only aware of the large virtual address space brought by the new 64-bit architecture, it also features refined power-efficiency implementation.
Without doubt, Apple successfully integrates its hardware with the iOS system, which allows them to optimize the software specifically for their hardware to save more power. Due to the variety of hardware, it’s much difficult for Google to do the optimization work, and the manufacturers just lack the willingness to do so as they are engaged to compete against each other for the limited market share.
Battery life is also Apple’s top priority. Take the sync mechanism as example, all apps running in iOS devices have to deliver the notification and push message via Apple’s push notification service called APNS. Basically iOS devices only have to create and keep a persist connection to Apple’s server for notification. Although Google does have similar services, Android apps often connect to their own server for push messages, which means many links to different servers. This could have a tremendous impact on battery life.
No body can deny the fact that app store have more quality apps than Android. In order to attract more developers, Google allows them to display ads to the target users. While iOS owners pay for the apps and games, Android users are waiting for their apps to connect and download ads in the background to generate a few bucks for the developers.
Android users are proud of the true multi-tasking; it sucks a lot on the precious battery life. Need it or not, many apps auto-start and create more than one services in the background for almost nothing. Even if you exit the app, the service still runs without your knowing.
This could make the battery thing much worse as handsets could not enter deep sleep, which is designed to save power. You could easily destroy your battery in hours with a few services running all the time.
Now iOS also has mult-tasking function, the good part is that you can choose which apps are allowed to refresh in the background.