The biggest problem with many Android flagships is the battery life. It seems like all manufacturers focus on is the number of cores and amount of RAM inside the device, not how well the experience will translate to the end-user. In the last year or so, though, Samsung has been the best about creating a good experience for the consumer, which is why when it comes to the Galaxy S4, we generally weren't too worried about poor battery life.
GSM Arena got its hands on the device and was able to perform a few battery life tests on it. While we've learned in the past that these tests can be somewhat artificial, they are usually a decent indicator as to the general range the battery life will fall into.
Overall, the results suggest that the 2600mAh battery in the Galaxy S4 will be able to last most people through a full day, but the more you use it, the sooner it will die, which, if you ask me, is common sense. But, let's go ahead and break it down further.
While not many people use their phones for actually calling people any more, we've all been stuck on those crazy-long conference calls before. With the screen off and processor idle, Samsung's latest flagship was able to last 13:53 hours of talk time. This is roughly 3.5 hours longer than the Galaxy S3 was able to last, which when you consider the beefier processor and screen the Galaxy S4 features, that's quite a feat. The Xperia Z, which has a smaller battery (2300mAh) and older processor, was able to last two hours more, though.
Many people would say that they use their device more for web browsing than calling, so this might be a much better indicator as to what kind of battery life us geeks can expect. The Galaxy S4 was able to browse the web for 8:42 hours on a single charge. This number is roughly two hours better than the Galaxy S3, and also beats the Nokia Lumia 810, ASUS Padfone 2, and Lumia 710. It's worth noting that the Galaxy Note II, iPad mini, and HTC One all did better on the test.
As someone who just endured a 7 hour car ride, I can say that the watching videos continuously can certainly drain a device's battery. The Galaxy S4 was able to perform the task for 10:16 hours continuously, which as GSM Arena notes, is not much better than the Galaxy S3. The device is beat by the Note II, Galaxy Premier, and RAZR MAXX, bet bests the HTC One, iPhone 5, and Lumia 710.
GSM Arena awarded the Galaxy S4 an endurance score of 63 hours. This number is based on "how long it will last between charges if you do an hour each of calling, web browsing and watching videos every day."
As we said before, these tests should always be taken with a grain of salt, and we should wait until consumers get their hands on the device before making any too strong of claims about the battery life.