How Much Battery Life can be Boosted by Project Volta?

It seems every large upgrade of Android, Google also announces a new kind of "Project", while this year,  google chose to focus on improving battery life of devices, named "Project Volta". While last year, google focused in improving user experience on Android by improving the user interface with Project Butter. Project Butter has successfully improve the previous laggy experience on Android, and providing a smooth 60 frames per second animation to let all animations on Android fluid and smooth. This has result in greatly improved user experience of Android, and most of the user starting to like Android.

While this year, KitKat has brought us a project called "Project Svelte", it lowers the minimum requirement of Android devices to run at 512RAM.

In 2014 Google I/O, this time they has released "the biggest changed since Android" -- Android L, Android L is Android 5.0, come after Android Kitkat (Android 4.4.x) Android L being us "Project Volta", Google said that Project Volta can contribute to at least 90 minutes increase in battery life for Nexus 5. 

How Much Battery Life can be Boosted by Project Volta? Ars Technica uses two Nexus 5 to test the battery life in Android L compare to Android 4.4 KitKat, there are some assumptions that they have used: One is installed with Android 4.4 Kitkat, while another installed with Android L preview, two are in same brightness 200nit, keep the screen on while testing, at the same time upgrading application, refresh website every 15s under Wi-Fi, until the battery drained out.

The experiment result shows that, the device with Android 4.4, the battery life is 345 minutes, while the one with Android L preview, the battery life is 471 minutes, the battery life has increased 36%, boosted around 2 hours time of usage.

One more thing, Android L also provides "Battery Saver" function, it can be configured as automatically activated while the battery is lower than 15%, "Battery Saver" will decrease the clock of CPU (decrease performance of device), cut off the 3G/4G data access, decrease the brightness of the display. Although this can further improve the battery life of the device while in low battery level, but this experiment did not test out this function yet.

"Project Volta" improve the battery life of device in several ways. First, "Project Volta" can find out the highest battery drainer application on your devices, and control the activity of these applications under "battery saver", to reach the goal of increasing battery life.

Google experiment find out that, while the user light up the display once, it used up 2 minutes of battery life. There are two causes of draining up the battery: one is battery drain by the display, while the second is refreshing or syncing data in the background would also causes battery drain. These battery drain problem can be improved in Android L. Android L uses a new "JobScheduler" API, let Android can more efficiently to group the data tasks, which saves the battery life.

Moreover, the improved Battery Historian application can create a statistics for the history of battery drain on your device, and this improved version has provide more features that could let the developers to optimise the battery usage of their applications.

Certainly, ART replaces Dalvik becomes the Android emulated environment is also one of the main contributors to the improved battery life in Android L, ART can translate the coding of Android applications into local code, decreasing the time needed to computing emulation, and increasing the performance of the Android L devices.