Two Day Battery Life?

Inside the Xperia Z3 is an 11.78 Wh (3,100 mAh at 3.8 V) non-removable battery, which Sony claims on their website is good for two days of battery life. So, to test that claim, I pledged to only plug in the Xperia Z3 to a wall charger once every two days throughout the period of the review. To my surprise, the handset held up pretty well with this punishment that would make other smartphones weep.

During my time using the Xperia Z3 as my daily driver, and only charging it once every second day, the device never died before day two was over. This is with my typical smartphone use that includes reading websites, sending emails, social networking, messaging, photography, calls and more each day. Most phones require a charge every night, but the Xperia Z3 seems to be an exception.

In the above three benchmarks, the Xperia Z3 boasts battery performance that’s relatively the same as the Xperia Z2. With similar hardware and a slightly smaller battery, this isn’t too surprising to see.

It’s with these benchmarks, the most important in our suite, that the Xperia Z3 sees significant gains. This is thanks to new display management technology that only refreshes the screen when the content on it changes. When displaying static imagery, like when you’re reading a webpage or viewing photos, the Xperia Z3 conserves its juice and provides better battery performance than its competitors.

You might think that the refresh technology is only useful for some circumstances, but throughout your day-to-day usage of a smartphone there are many cases where content on the screen is not changing. Even if these cases are only a fraction of a second long, not refreshing the display continuously improves battery life, as can be seen both in these benchmarks and in my general usage of the handset.

However, the technology is not advantageous at all when the screen needs to constantly refresh, like in a game or when you’re watching a video. This is why there is not a significant battery life improvement in the first set of benchmarks.

The Z3 also comes with several battery saving features that can be enabled to extend its life. There’s Stamina mode, which extends life by turning off connectivity features when the display is off. You also get location-based Wi-Fi, a standard low battery mode that disables some functions when the battery dips below a certain level, and Ultra Stamina mode. The latter disables nearly every feature of the phone, restricting it to basic functionality like the ultra power saving modes of the Z3’s competitors.