Best answer: In our testing, we’ve found it possible to push 7-8 hours of real-world use on the 4K equipped Dell XPS 15, which is nothing to turn your nose up at.
A beast of a laptop: Dell XPS 15 with 4K display (From $2,009 at Dell)
Big battery, thirsty display
On paper, the Dell XPS 15 is well equipped for excellent battery life. The higher-spec model comes with a larger 86Whr battery, which is smaller than previous-generation models but, thanks to advancements in efficiency, offers the same sort of battery life.
Nevertheless, a 4K display is simply more power-hungry than a 1080p display down to having more pixels to power.
Surprisingly good performance
That’s not to say that you can’t get some decent battery life from a 4K equipped XPS 15. During our testing, we’ve been seeing 7-8 hours of real-world use from the 4K equipped XPS 15, which is still pretty impressive.
However, it should also be noted that pushing heavy workloads that tax the CPU, GPU, or both, such as gaming or video editing, will see that drop reasonably sharply. In situations like this, you’ll want to make sure you keep your charger handy if you’re away from home or the office for an extended period.
It comes down to how you use it, like any laptop. If you’re getting a 4K display for something like video editing, you will always need to carry a charger. But that’s true of just about any laptop right now.
Dell XPS 15 with 4K display
A beastly machine that dazzles
The refreshed XPS 15 brings new processors, a faster GPU, and retains its 4K display option. Excellent performance, a large battery, and plenty of configuration options make this one of the best 15-inch “power” laptops on the market.