TABLE OF CONTENTS Two of the most important components today in a mobile device are the battery and the display. It can be argued, that if battery and display technology had not evolved as fast as it did these last few years, features like color displays, high-speed data applications, assisted global positioning system (GPS), and 3D graphics would not be available in a portable device.
As mobile devices evolved from analog to digital technology, batteries for mobile devices evolved from sealed lead acid (SLA) to nickel metal hydride and subsequently to lithiumion. Since handset power demands were dropping, at the same time that battery energy densities were rapidly increasing, all was well, and both standby times and talk-times shot up like a rocket. Today it's not unusual for digital handsets to have standby time in excess of a week, and customers have come to expect this.
The problem is that batteries are having difficulties in keeping up with today 's mobile handset power demands. As handsets acquire color screens, cameras, and broadband access technologies, power demands have been quickly inching up, but battery storage capacities are not keeping pace. For example, the first 3G W-CDMA handsets introduced in Japan by NTT DoCoMo had standby times typically less than 24 h. The performance gap was an issue to the Japanese accustomed to standby times of almost 2 weeks. As a result 3G broadband wireless technologies have been slow to be accepted by the consumer.
Future battery developments will be...
