If a human turned into a phone, then their heart would become the battery. That electrically-charged piece of equipment is what'll keep your phone running for hours (and hopefully not just minutes). This plays a large part when consumers are looking for a new phone - after all, no one wants to charge their phone every hour.
GSMArena, home to many phone reviews and updates, just released their findings on battery tests done on the latest Samsung Galaxy S III. We already know that the S III is packing a whopping 2,100mAh battery, but how well does it actually fare when one considers screen size and display quality?
In its most basic function, talking on the S III will result in over 10 hours of call-time. Impressive, right? But, remember that when you're talking on a phone, the screen will be off. A different test utilized the phone's web browser and network connection, which resulted in over 5 hours of use - just a little more than half of the call-time. Surprisingly, when just playing videos, the S III came up to 10 hours and 1 minute.
A reason for this could be network-use draining battery life. Another reason could be that the phone is simply powerful enough to play video without too much constraint. Overall, the battery seems fairly solid and is definitely an advantage against other phones.
Source: gsmarena (blog), gsmarena (results)