Issues with Samsung Galaxy SIII

• Battery Drain is due to an error at Samsung's end while compiling the firmware version. Please update your devices to the latest software version to fix it. Before reporting about the battery, kindly check for battery draining apps & keep an eye on your Screen On times.
• Memory Leak is a condition where a certain service takes a lot of RAM and locks it, making it impossible for Task Killers to free up RAM and thus, slows down the phone showing you low memory errors. This is another problem that should be fixed with an update. For rooted users, please refer to XDA forums & you should find a flashable zip that solves this.
• PS: there are some apps that prevent the phone from going into sleep when you lock your phone. Such apps or services should be identified and killed. Or they would keep sucking on your batteries & CPU.