The Samsung Galaxy S20 Ultra has a huge 5,000 mAh battery, so you would expect it to last a long time on a charge. However, while this phone offers a lot of endurance with the display in 60Hz mode, using the 120Hz refresh rate on the Galaxy S20 ultra's screen take a huge toll on battery life.

We put the Galaxy S20 Ultra through our battery test four times, which involves continuous web surfing over cellular (in this case T-Mobile 5G) at 150 nits of screen brightness. Two of the tests were run with the display set to 60Hz mode and two were in 120Hz mode.

With 60Hz mode on, the Galaxy S20 Ultra averaged 11 hours and 58 minutes, which is a great result and enough to earn this device a spot on our best phone battery life list. We consider any smartphone that gets above 11 hours to be very good and anything that approaches or exceeds 12 hours of runtime to be great.

However, it was a completely different story when we turned on the Galaxy S20 Ultra's 120Hz mode, which is designed to provide smoother motion when scrolling, playing games and more. This Android phone lasted only 9 hours and 13 minutes, which is nearly 3 hours less than with 60Hz turned on.

Galaxy S20 Ultra battery life vs competing phones

Battery life (hrs:minutes) Battery size Samsung Galaxy S20 Ultra (60Hz) 11:58 5,000 mAh Samsung Galaxy S20 Ultra (120Hz) 9:13 5,000 mAh Samsung Galaxy S10 Plus 12:35 4,100 mAh iPhone 11 Pro Max 11:54 3,969 mAh iPhone 11 11:16 3,190 mAh Samsung Galaxy Note 10 Plus 10:47 4,300 mAh Google Pixel XL 9:42 3,700 mAh

The good news is that you can easily toggle between 60Hz and 120Hz under settings on the Samsung Galaxy S20 Ultra. And the 60Hz mode is enabled by default.

While the Galaxy S20 Ultra's best battery life result is good, it's a step behind the Galaxy S10 Plus' runtime of 12:35. This could be for a couple of reasons. First, the Galaxy S20 Ultra has a larger 6.9-inch display, compared to 6.4 inches for the S10 Plus. Second, the S20 Ultra has a 5G modem, which likely uses more power than 4G.

Still, the Galaxy S20 Ultra Galaxy Note 10 Plus beat the Galaxy Note 10 Plus, which has a similarly sized 6.8-inch display. The Note 10 Plus lasted just 10:47 with its 4,300 mAh battery, so the S20 Ultra's 5,000 mAh battery definitely gives it an advantage.

The iPhone 11 Pro Max turned in a similar time to the S20 Ultra with 11:54. Apple's flagship phone has a smaller 6.5-inch display with a 60Hz refresh rate. However, rumors suggest that the iPhone 12 will offer a 120Hz rate, similar to the ProMotion displays on the iPad and iPad Pro.

The bottom line is that you can get great battery life out of the Samsung Galaxy S20 Ultra, but you'll need to have the display on 60Hz.