The more our cell phones come to resemble miniature computers, the harder it is to eke out decent battery life, leaving some of us with little more than fancy bricks at the end of a long day. In order to get a better sense of what exactly saps the juice from cell-phone batteries, I talked to a few people in both the chip and handset worlds.
The biggest battery drain, according to my sources, comes from the display, which is one reason it’s going to be hard for iPhones and such to move much beyond 4-inch displays with current technology. A solution can be found in organic light-emitting diodes (OLEDs). Samsung has demoed OLED screens of some 14 inches that consume about 1 watt of power; displays measuring 6-7 inches that consume about 750 milliwatts are theoretically possible as well.
After the display, the chips and applications running on those chips can act as a drain. The chip industry is keen on boasting how their Atom or ARM processors consume very little power, and indeed, most cell phone semiconductors have an array of features designed to keep power consumption down, such as figuring out how far the phone is from a base station based on the signal strength and amplifying its signals only as much as it needs to in order to reach that station. Basically it only yells as loud as it needs to in order to be heard.
Other chips, such as Wi-Fi or GPS, can be turned off when not in use, so they don’t continually seek out networks or satellite signals. In other words, if you’re concerned about power, Wi-Fi VoIP may not be the application to use. Ditto for a social networking app that uses GPS or Wi-Fi to find friends wherever you are. Other battery-intense applications include watching movies or web surfing, primarily because they keep the display lit.
The final element is just that — the elements. Cold weather saps batteries by preventing them from reaching their full potential. If you can keep your phone close to your body rather than in a purse or bag, it can help a little, but in general if you’re freezing, your battery is, too.