A:
The AT&T SGS3 will offer a battery life expectancy of:
Battery, Standby 3G: Up to 12.5 Days; 4G: Up to 8.3 Days*
Battery, Talk Time Up to 8 hours*
Battery power consumption depends on factors such as network configuration, signal strength, operating temperature, features selected, vibrate mode, backlight settings, browser use, frequency of calls and voice, data and other application usage patterns.
-MrSamsung