In this age of ubiquitously connected embedded, mobile and wireless devices, system developers – and end users – are faced with the problem of making sure these untethered applications are properly supplied with power, usually through batteries.
Proper design in this environment is more than choosing the right low power components – and making sure the specs for current draw and leakage are within the limits projected for the application. In systems such as those in many consumer applications where humans are involved, it also means providing mechanisms for energy and battery management that give system developers – and the end users – the ability to determine the status of a device's power sources and take meaningful action, both immediate and long-term.
This need is readily apparent in consumer electronics, mobile devices, and the new wave of wearable IoT devices. One needs only look at the hundreds of apps for monitoring and managing energy consumption on Android and iOS devices. Some display the current battery level and an estimate of battery life based on general use and duration. Others display CPU and/or memory usage of apps and enable users to terminate them. And still others show battery drainage or device temperature over time. However, until now such lightweight apps have been general in nature, non-specific in their remedies, and not very useful in many cases.
This is beginning to change with more and more efforts being made to provide useful energy and battery management schemes, as you will note in the design articles included in this week's Tech Focus newsletter. Initially many of these solutions are for mobile phones, but increasingly the same capabilities are emerging for a wide variety of wireless embedded and consumer IoT devices. The standards needed, such as Battery Interface (BIF), are also beginning to be deployed. Described in “Managing the rechargeable batteries in your embedded-mobile design,” BIF is one of the most all-pervasive battery related standards I have come across in its scope and potential impact.
BIF is initially focused on the mobile phone market with a specific set of features and capabilities; I believe it is extensible into new market segments such as consumer wearables and the Internet of Things. But the challenges facing developers and companies as they move into these increasingly battery-dependent operating environments are many and you will need all the help you can get. Fortunately, more tools and ideas are emerging, good examples of which are the articles and papers I’ve included in my Editor's Top Pick list:
Reducing battery discharge rates in CR-2032-based portable embedded designs
Meeting the demand for low power in embedded designs that last 10, 15, or 20 years requires integrated MCUs that meet the requirements of the battery subsystem, as well as those of the untethered environment in which it will operate.
Effective battery management system design
Available battery and fuel gauge products have challenges and limitations, especially when applied to battery management. Here are some tips for developers designing both portable devices and the batteries to power them.
Reducing display power to extend mobile battery life
Techniques for use on ARM-based mobile smartphones and tablet computers to reduce the power dissipation of display subsystems and provide longer battery life even during multimedia activities.
At the core of any design is how well your software code takes advantage of the underlying hardware. For that I recommend “Optimizing embedded software for power efficiency”, a series of articles by Freescale's Rob Oshana and GE's Mark Kraeling, and “Maximize the battery life of your embedded platform”, by ARM's Chris Shore.
As you move into such applications, I would like to hear from you about your ideas, the problems you have faced, and how you have solved them, as well as the tools and techniques you used.
Embedded.com Site Editor Bernard Cole is also editor of the twice-a-week Embedded.com newsletters as well as a partner in the TechRite Associates editorial services consultancy. He welcomes your feedback. Send an email to , or call 928-525-9087.