If you thought having a 5.5-inch QHD display would have a massive impact on the battery life of a smartphone, think again.
A prototype version of the phone was put through a very unscientific battery test thanks to hi-tech.mail.ru, but the results seem promising. According to the site, they have tested the G3 with maximum brightness and the phone manages to crank out about 6 hours and 30 minutes of screen-on time, which means the screen was actually on for a total of 6 and a half hours and not how long the actual battery lasted.
LG claimed during its event, that they have used adaptive frame rate, adaptive clocking, and adaptive timing control technologies to help reduce the power consumption of the QHD display to match its 1080p counterparts and we can see it in action here.
Although. if you are wanting for a more scientific battery test, I suggest you wait for tests from more reputable sites like AnandTech.