Nobody likes to have their smartphone’s battery drain quickly, especially when the source of that power drain looks to be the phone’s radio itself. Those who picked up the Samsung Galaxy S3 i9300 when it came out have been discussing this very issue.
Battery Usage statistics report that Cell standby is the main culprit—sometimes accounting for 50-70% more than even the Screen or Android System. How can that be when the battery seems to drain normally? XDA Senior Member Andreilux did some testing and discovered that the system was reporting the wrong value for a reason: Samsung made a mistake.
It would seem that the issue comes from an error in framework-res.apk. XDA Recognized Contributor bala_gamer explains that the power drain value setting for Cell standby is erroneouslyset to 34 mA (practically impossible) instead of a more reasonable value of 3.4 mA in power_profile.xml within framework-res.apk. He then put together a corrected power_profile.xml, and provided a quick step-by-step guide to pushing the change. Those not excited about messing directly with framework-res.apk can thank Senior Member ausdim for providing a recovery-flashable update.zip.
Bala_gamer notes that:
This mod will fix the wrong reporting of “cell stand by “usage to some extent. If your mobile has actual drain due to signal issues or some other issues do not blame me or any other for not fixing this.
Note that while this will help the system report more accurate battery usage for Cell Standby, it is far from perfect, and there will still be inaccurate values reported for other items. For more information about the fix, visit the original thread.