How to Extend Battery Life in Mobilized Applications

Challenge

Implement the principles of Application Power Management for Mobility to extend battery life in mobilized applications. A good user experience and longer battery life are critical factors for mobile systems. Application software has a key role to play in improving user experience as well as in extending battery life.

Solution

Reduce the performance/quality of features, turn off background activities, or both. Implementing these operations in an application increases the processor idle time. Since processor power consumption when idle is significantly lower than when active, this results in longer battery life.

There is no pre-defined list of performance/quality features and background activities for extending battery life. The performance/quality features and background activities are specific to an application. Some examples could include the following:

Reducing the quality of video and audio playback in a DVD application to extend playtime while traveling.
Turning off automatic spell check and grammar correction within a word-processing application to finish the document when the battery is low.
Reducing the frequency of stock-quote updates in Web-based financial applications to remain online longer.

When a system is battery powered, applications can extend battery life. In addition, applications can define other criteria to determine when to extend battery life. These other criteria can be based on current battery power status, current system power scheme, or both.

For example, an application can extend battery life when one or more conditions below are met:

The percentage of remaining battery power is below a specific threshold.
The remaining battery time is below a certain amount of time.
The system is using a particular power scheme.

An application’s User Interface (UI) can provide options for specifying both how and when to reduce performance/quality of features, to turn off background activities, or both. User input is important, since users know their requirements and their environment best. The user experience may not be optimal if applications predefine these settings without any options to change them in the UI.

The relevant measures for an application to extend battery life include the following:

Identify the application features where users may be willing to reduce performance/quality for extended battery life.
Identify the application background activities that users may be willing to turn off for extended battery life.
When a system is battery powered, the application can extend battery life. In addition, the application can define other criteria to determine when to extend battery life. These other criteria can be based on current battery power status, current system power scheme, or both.
Design and implement a UI so users can specify both how and when to reduce performance/quality of features, and/or to turn off background activities.
Implement application logic to retrieve system power information and determine when to reduce performanc e/quality of features, and/or to turn off background activities.
Implement application logic to reduce performance/quality of features, and/or to turn off background activities.

This item is part of a series of Knowledge Base items that discusses the concept of Application Power Management for Mobility; the other items in the series are as follows:

Resource

Applications Power Management for Mobility