The best answer: In our tests, we have found that it is possible to boost 7 hours of real-world use on the Dell XPS 15 7590 equipped with OLED 4K, which is nothing to bother you.
A laptop beast: Dell XPS 15 7590
Huge battery, thirsty screen
On paper, the Dell XPS 15 is well equipped for excellent battery life. The highest specification model comes with a 97Wh battery, which is not only the largest Dell can put inside, it is almost the largest you can carry on an airplane.
But this is one of those situations where size matters, with the option of two 4K screens on offer. You can get one with a non-touch 4K OLED touch screen or a normal 4K touch screen. And when you push so many pixels, your battery will always be affected.
Surprisingly good performance
That doesn't mean I can't get a decent battery life from an XPS 15. equipped with 4K. Full review, the executive editor, Daniel Rubino, found it quite nice.
The battery life with the Core i9 is surprising in a good way. If you are using the XPS 15 as a laptop (web browsing, Office and email), it is possible to press seven hours with the screen at 50 percent. That number is not surprising, but for something with a 4K OLED display and possibly an exaggerated Core i9, it is much better than I expected.
However, it should also be borne in mind that pushing heavy workloads that tax the CPU, GPU, or both, such as video game or game editing, will see that fall for hours. In these cases, we have seen up to four hours of life, which is still not bad in all things considered.
It's about how you use it, like any laptop. If you are getting a 4K screen for something like video editing, you will always need to carry a charger. But that is true for any laptop at this time.
Dell XPS 15 (7590)
A beastly dazzling machine
The updated XPS 15 (7590) for 2019 brings new processors, a faster GPU and an option for 4K OLED. Also, the camera is now in the upper screen. The excellent performance, a large battery and many configuration options make this one of the best 15-inch "power" laptops on the market.