The reason for this is a file on the smartphone that contains the drain value was wrongly set when the device shipped. This file, known as the framework-res.apk, was set at 34mA when it should have been set at 3.4mA.For an owner of the Galaxy S3, this means the phone may incorrectly display a 50 percent to 70 percent battery drain, as Auto-O-Mobile has pointed out.
Users experiencing this problem can fix it by changing the power_profile.xml file located in the framework-res package. To do this, complete the following steps:
1. Download the updated file (510kb) from MediaFire.
2. Save the file on your microSD card or internal storage.
3. Reboot your Samsung Galaxy S3 into ClockWork Mod (CWM) Recovery Mode.
4. Choose "Install zip from SD card" and select the downloaded file.
5. Reboot your device. This should solve the battery drain issue.
Please do not forget that there is a possibility this process could lead to a voiding of the device's warranty.