When the next version of Android arrives, don't be surprised if your phone can run longer on a single charge. Project Volta, part of Android L, is the reason. Google devoted an entire session at Google I/O to Project Volta, which optimizes power consumption on an Android device and also provides some developer tools to help make more battery-efficient apps.
While Android L is only available in a developer preview, we can already see the potential of Project Volta thanks to Ars Technica's Ron Amadeo. He used the same standard and repeatable battery test Ars typically uses to measure Android device battery life. The findings with Android L? Amadeo's Nexus 5 phone lasted two hours longer with Android L as compared to Android KitKat, a gain of 36 percent.
So what's the secret sauce in Project Volta that makes Android L more power-efficient? It's a number of different things that quickly add up to more battery life. In the Project Volta session at Google I/O, Google said it scrutinized how different components use power, and for how long, in various but typical circumstances.
Passing data through the cellular radio obviously causes a spike in power usage, for example, but the radio doesn't drop back to a sleep state for several seconds. Turning on the phone's display just to check for new notifications can quickly gobble up battery power as well. After examining these and other use-cases, Google determined that for every one second of "active" use on a typical phone, standby time is reduced by a full two minutes. If you have 50 apps that are active for a second, then — say for synching, polling or showing notifications — that's 100 minutes of standby time gone.
Enter Project Volta, which groups and schedules certain tasks in a more efficient manner. It also includes new APIs for developers to take a similar approach and reduce the overall number of power-intensive activities needed for their apps to work. There's a new network activity awareness API, for example, so that apps can determine if the cellular radio is active, in which case an app can "piggyback" on the connection instead of later waking up a sleeping radio.
That's just one of many Project Volta enhancements; you can hear about all of them in this recording of the Project Volta session from Google I/O 2014.