When Apple announced the iPhone 13 Pro Max, it claimed battery life improvements of about 2.5 hours over the iPhone 12 Pro Max. Multiple tests have shown that Apple’s claims are indeed true, with the iPhone 13 Pro Max even managing to last nearly 10 hours in a battery drain test. Now, YouTuber PhoneBuff has pitted the iPhone 13 Pro Max against the Galaxy S21 Ultra in a battery test to see which phone offers the best battery life.

The Samsung Galaxy S21 Ultra features a 6.8-inch LTPO AMOLED panel with a 5,000mAh battery. The iPhone 13 Pro Max has a similarly-sized 6.7-inch 120Hz ProMotion AMOLED display but comes with a smaller 4,352mAh battery. So, on paper, the iPhone 13 Pro Max is at a disadvantage compared to the Galaxy S21 Ultra.

Thanks to the tight integration between hardware and software and the power-efficient A15 Bionic chip, the iPhone 13 Pro Max outlasts the Galaxy S21 Ultra by 2.5 hours in PhoneBuff’s battery test. In fact, it was the longest-lasting smartphone in the test so far. The test involved running Instagram, Google Maps, messaging, watching videos on YouTube, listening to music on Spotify, and more for an hour each.

The entire test by PhoneBuff is automated, so there’s little reason to doubt the results here. Ultimately, these tests confirm one thing: if you want a smartphone with the best battery life possible, the iPhone 13 Pro Max is the one you need to buy.