The Samsung Galaxy S 4 i9505 got a software update and GSM Arena updated their battery life tests. Overall the new software has resulted in longer talk, video playback and standby time, while reducing web browsing endurance a bit.
Samsung Galaxy S 4 (after update) - 18 hours and 3 minutes
Sony Xperia Z - 16 hours and 3 minutes
LG Optimus G - 15 hours and 30 minutes
Samsung Galaxy S 4 - 13 hours and 53 minutes
HTC One - 13 hours and 38 minutes
Apple iPhone 5 - 8 hours and 42 minutes
HTC One - 9 hours 58 minutes
Apple iPhone 5 - 9 hours and 56 minutes
Samsung Galaxy S4 - 8 hours and 42 minutes
Samsung Galaxy S 4 (after update) - 7 hours and 24 minutes
Sony Xperia Z - 6 hours and 27 minutes
LG Optimus G - 5 hours and 15 minutes
The Super AMOLED display does consumer more power when displaying light colored or white backgrounds, and thus will suffer a bit in web browsing tests, most webpages being white.
Samsung Galaxy S 4 (after update) - 12 hours and 30 minutes
Samsung Galaxy S 4 - 10 hours and 16 minutesApple iPhone 5 - 10 hours and 12 minutes
HTC One - 10 hours and 2 minutes
LG Optimus G - 7 hours and 30 minutes
Sony Xperia Z - 5 hours and 39 minutes
The Super AMOLED display is more efficient in video playback tests.
Standby (with 1 hour of calls, video playback and web browsing per day)
Samsung Galaxy S 4 (after update) - 69 hours
Samsung Galaxy S 4 - 63 hours
Apple iPhone 5 - 51 hours
Samsung Galaxy S III - 50 hours
HTC One - 48 hours
Sony Xperia Z - 48 hours
LG Optimus G - 45 hours
Overall, the update is a plus insofar as battery life is concerned.