Battery life is often the Achilles heel of all but the rarest of notebooks. For every Dell XPS 13 or MacBook Air with marathon time away from the wall, there's an Alienware 17 that pretty much negates any possibility of gaming on the go. Then again, said MacBook Air can't let you play a Batman game practically maxed out at 1080p.
Besides, the ZenBook Pro UX501 offers itself up not as an exclusive gaming notebook, but a portable to please a variety of groups. A jack of all trades suited equally for work and play.
 | Battery Life
| Heavy and Light Loads |
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We put the Asus ZenBook Pro UX501 through two battery life benchmarks: Battery Eater Pro and our own Web browsing test. Battery Eater Pro creates a heavy workload to grind your system’s battery down, while the HotHardware.com test refreshes a Web page regularly, giving you a general impression of what the battery life might look like if you use it for light to medium online tasks.
During both rundown tests, we reduce the screen's brightness to 50% (which is perfectly bright enough indoors) and leave stuff like WiFi and Bluetooth enabled. We also switch off any keyboard backlighting.

We have a winner! Despite having a power-sucking 4K touchscreen display, the UX501 clocks nearly 3 hours under load, which is nothing short of a monumental victory.
During light duty the UX501 registers closer to 4 hours of battery life. Not nearly enough to get through an entire work day, but considerably longer than the HP Omen that's been taunting it throughout our review process. I expected more based on Asus' claim of 6 hours, but that's normally how these battery tests shake out. In our experience clocking nearly 4 hours of continuous use with a 4K touchscreen-enabled notebook is nothing to scoff at.