Galaxy S21 Ultra 5G battery life: the longest lasting Samsung flagship?

So how long will the S21 Ultra battery last users in the real world?

In real world use, we were getting north of 7 hours of screen time on the S21 Ultra, which is a great score and actually a bit more impressive than rivals like the iPhone 12 Pro Max, but to confirm that and see the details, we turn to our battery tests!

Web Browsing Test (Wi-Fi, 200 nits brightness)

On our lightest test, web browsing, the S21 Ultra outlasted other flagships by a huge margin, and it scored impressively well even when it was running at the 120Hz Adaptive rate. We definitely recommend that smoother and more pleasing 120Hz mode, especially with such great battery life, but if you switch to 60Hz, you will indeed squeeze a bit more on this test. At 60Hz the S21 Ultra scored more than 16 hours, an all-time record for flagships!

YouTube Test

On our second test, streaming YouTube videos from the same playlist at the same, 1080p quality, the S21 Ultra once again shows it can last. It's not quite as far ahead in this test, and we would say that it lasts roughly as long as the iPhone 12 Pro Max and the Pixel 5.

3D Gaming Test

Last but not least, we have our gaming test, and if you enjoy games like Call of Duty, PubG and Minecraft, look closer, this is the test you should care about. While the other two tests strain the CPU, this one pushes the GPU to the max and shows how effective it is.

And once again, the Galaxy outlasts rivals by quite the margin. Notice, however, that running this same test at 120Hz with compatible games like Minecraft, they do drain a lot more of the battery, so if you want a balance between performance and battery life, it really makes sense to game at 60Hz.

And here is how the battery sizes compare for all Galaxy S21 series phones, and a few other recent Galaxies:

The biggest news about the S21 Ultra and charging are probably that you won't even get a charger in the box. Following Apple which set the charger-less tone with the iPhone 12 series, Samsung has quickly decided to follow and removes the charger from all S21 series phones (you still get a standard USB to USB-C cable at least). 

So what charger is the best charger for the S21 Ultra? The phone supports up to 25W charging speeds (disappointing, considering last year's model could charge at up to 45W). With no charger in the box, most people would probably still be best off with the compact and affordable 25W Samsung fast charger sold for $35 (but currently discounted for $23 at Best Buy). We tested the phone with this charger and a full top-up takes around an hour and a half. With other phones by OnePlus and Xiaomi being able to fully charge their flagships in around 40 minutes, this looks really slow.

Of course, the Galaxy S21 Ultra also supports wireless charging, and Samsung is introducing a couple of new wireless charging to go with it. Maximum supported wireless charging speeds are 15W, and we recommend getting a Samsung-made charger that supports this maximum speed for faster top-ups.