The research paper was authored by Purdue graduate students Xiaomeng Chen, Abhilash Jindal and Ning Ding; and Intel researchers Maruti Gupta and Rath Vannithamby.

"Being able to reduce the total daily energy drain by about 16 per cent is rather significant because you can extend the battery charge by one-sixth," Hu said.

The key insight behind the proposed solution, HUSH, is that background activities of individual apps are not equally important to individual smartphone users.

For example, frequent Facebook updates during screen-off may be useful to a user who checks Facebook feeds and reacts to notifications often, but they are much less useful to another user who rarely checks such updates.

The HUSH system dynamically identifies app background activities that are not useful to the user experience on a per-app basis and suppresses such background app activities during screen-off to reduce the battery drain.

When the phone is in screen-off, it also continues draining power for various legitimate maintenance purposes - for example, A WiFi beacon, when the phone's WiFi system sends a periodic signal to the access point once every 200 milliseconds, and a "cellular paging" function, when the phone talks to the base station every 1.28 seconds to check for incoming calls or data.

In efforts to extend battery life, researchers will work to reduce energy drain from these legitimate functions as well as faulty apps.