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Samsung Galaxy S21 Ultra 5G (Snapdragon) Battery test: Solid performance

This device has been retested in the latest version of our protocol. Overall, sub-scores and attributes are up to date. For detailed information, check the What’s New article

Samsung launched the Snapdragon version of its Galaxy S21 Ultra 5G smartphone in January 2021 at a price point that puts it into our Ultra-Premium ($800 and higher) segment. The phone takes a 25W charger (not included) for its 5000 mAh battery, which powers quite a number of top-end features, including a large AMOLED 2X display and a quad-camera setup that includes a high-resolution 108 MP main camera.

We recently put the Samsung Galaxy S21 Ultra 5G (Snapdragon) through our comprehensive Battery protocol tests and present our findings here.

Key specifications:

  • Battery capacity: 5000 mAh
  • 25W charger not included
  • Wireless charging
  • 6.8-inch, 1440 x 3200, 120 Hz AMOLED display
  • Qualcomm Snapdragon 888 (5 nm) chipset, 5G
  • Tested ROM / RAM combination: 128 GB + 12 GB

About DXOMARK Battery tests: For scoring and analysis in our smartphone battery reviews, DXOMARK engineers perform a variety of objective tests over a week-long period both indoors and outdoors. This article highlights the most important results of our testing. (See our introductory and how we test articles for more details about our smartphone Battery protocol.)

Test summary


Sub-scores and attributes included in the calculations of the global score.

Samsung Galaxy S21 Ultra 5G (Snapdragon)














Key performances

Charging Time
2 days
Battery life
Charging Time
80% Charging time
Charging Time
Full charging time
Quick Boost
3h17 autonomy
after 5-minute charge
Please be aware that beyond this point, we have not modified the initial test results. While data and products remain fully comparable, you might encounter mentions and references to the previous scores.


  • Provides more than 2 days (~56.5 hours) of autonomy with moderate use
  • Better autonomy and power consumption than the competition for several use cases


  • Poor autonomy when using camera on the go
  • Consumes a lot of power at night

The Samsung Galaxy S21 Ultra 5G (Snapdragon)’s overall Battery score of 70 puts it just on the lower side of average among all the tested devices in our database thus far. Among its ultra-premium stablemates, however, that 70 puts it in second place.

We compared the Samsung Galaxy S21 Ultra 5G (Snapdragon)’s performance in several key categories with three other ultra-premium devices, the Oppo Find X3 Pro, the Samsung Galaxy S21 Ultra 5G (Exynos), and the Apple iPhone 12 Pro Max; battery capacity, charger, display type and resolution, and processor specifications for all four devices are shown in the table below.

Samsung Galaxy S21 Ultra 5G (Snapdragon) Apple iPhone 12 Pro Max Oppo Find X3 Pro Samsung Galaxy S21 Ultra 5G (Exynos)
Battery (mAh) 5000 3687 4500 5000
Charger (W) 25W 20W 65W 25W
Resolution 1440 x 3200 1284 x 2778 1440 x 3216 1440 x 3200
Processor Qualcomm Snapdragon 888 Apple A14 Bionic Qualcomm Snapdragon 888 Exynos 2100

Autonomy (58)

How long a battery charge lasts depends not only on battery capacity, but also on other aspects of the phone’s hardware and software. The DXOMARK Battery autonomy score is composed of three performance sub-scores: (1) Stationary, (2) On the go, and (3) Calibrated use cases. Each sub-score comprises the results of a comprehensive range of tests for measuring autonomy in all kinds of real-life scenarios.

Light Usage
Light Usage
Active: 2h30/day
Moderate Usage
Moderate Usage
Active: 4h/day
Intense Usage
Intense Usage
Active: 7h/day

The Samsung Galaxy S21 Ultra 5G (Snapdragon)’s overall Autonomy score puts it almost in the middle of all devices we have tested so far, regardless of segment. Here are a few more details:


Samsung Galaxy S21 Ultra 5G (Snapdragon)



Vivo Y72 5G
Best: Vivo Y72 5G (104)

A robot housed in a Faraday cage performs a set of touch-based user actions during what we call our “typical usage scenario” (TUS) — making calls, video streaming, etc. — 4 hours of active use over the course of a 16-hour period, plus 8 hours of “sleep.” The robot repeats this set of actions every day until the device runs out of power. 

The Samsung Galaxy S21 Ultra 5G (Snapdragon) achieves more than 2 days of autonomy — a bit more than 56.5 hours — in our TUS testing. That’s 10 hours more than both the Oppo Find X3 Pro and the Exynos version of the Samsung device, and 4.5 hours fewer than the iPhone 12 Pro Max; across the entire database as a whole thus far, the Snapdragon version’s result translates as a bit below average.

Typical Usage Scenario discharge curves

On the go

Samsung Galaxy S21 Ultra 5G (Snapdragon)



Samsung Galaxy M51
Best: Samsung Galaxy M51 (96)

Using a smartphone on the go takes a toll on autonomy because of extra “hidden” demands, such as the continuous signaling associated with cellphone network selection, for example. DXOMARK Battery experts take the phone outside and perform a precisely defined set of activities while following the same three-hour travel itinerary for each device.

The Snapdragon version showed considerably better autonomy on the go when it came to using social apps and GPS, and came in slightly ahead of the iPhone for making phone calls. That said, it was a bit behind both the Oppo and the Apple devices when using its camera.

Autonomy for on the go use cases (full charge)


Samsung Galaxy S21 Ultra 5G (Snapdragon)



Samsung Galaxy M51
Best: Samsung Galaxy M51 (100)

For this series of tests, the smartphone returns to the Faraday cage and our robots repeatedly perform actions linked to one specific use case (such as gaming, video streaming, etc.) at a time. Starting from an 80% charge, all devices are tested until they have expended at least 5% of their battery power.

The Samsung Galaxy S21 Ultra 5G (Snapdragon) had good autonomy in our 4G gaming tests

The Samsung Galaxy S21 Ultra 5G (Snapdragon) had good autonomy in our 4G gaming tests. It did slightly better than the competition when it came to 3G calling; did better than the iPhone 12 Pro Max for video playback; and was better than the Exynos version and the Find X3 Pro for 4G music streaming.

Autonomy for calibrated use cases (full charge)

Charging (78)

The DXOMARK Battery charging score is composed of two sub-scores, Full charge and Quick boost. Full charge tests assess the reliability of the battery power gauge; measure how long it takes to charge a battery from 0% to 80% capacity and from 80% to 100%; and measure how long and how much power the battery takes to go from an indicated 100% to an actual full charge. With the phone at different charge levels (20%, 40%, 60%, 80%), Quick boost tests measure the amount of charge the battery receives after being plugged in for 5 minutes. 

in 30 min
0 - 80%
Full charge
in 30 min
0 - 80%
Full charge

Samsung Galaxy S21 Ultra 5G (Snapdragon) has good charging time considering the power of the charger (25W).

Power consumption and battery level during full charge
Power consumption and battery level during wireless full charge

Full charge

Samsung Galaxy S21 Ultra 5G (Snapdragon)



Black Shark 5 Pro
Best: Black Shark 5 Pro (121)

The Samsung Galaxy S21 Ultra 5G (Snapdragon)’s total charging time to go from a completely empty battery to completely full is exactly 1 hour 28 minutes, which is just a few minutes better than the Exynos version (1 hour 33 minutes). Both Samsungs are way ahead of the Apple iPhone 12 Pro Max (2 hours 27+ minutes), but take more than twice as long as the Oppo Find X3 Pro (just under 37 minutes). As you can see in the following chart, the Snapdragon version maintains its lead over its Exynos twin in every test step:

Time to full charge
Time to full charge

As for wireless charging, the S21 Ultra 5G (Snapdragon) takes 1 hour 57 minutes to charge to 100% (per the device UI) and an additional 30 minutes to reach the full charge capacity. Again, this is faster than the Exynos version by a little bit; faster than the Apple device by a lot; and rather a ways behind the Oppo device.

Quick boost

Samsung Galaxy S21 Ultra 5G (Snapdragon)



Realme GT Neo 3
Best: Realme GT Neo 3 (111)

Users plugging in the Snapdragon version of the Galaxy S21 Ultra 5G for five minutes with less than 50% battery power left will find that they gain more than 3 hours of autonomy.

Samsung Galaxy S21 Ultra 5G (Snapdragon) Apple iPhone 12 Pro Max Oppo Find X3 Pro Samsung Galaxy S21 Ultra 5G (Exynos)
Autonomy boost (hh:mm) 20%3:24 3:17 5:49 3:01
40%3:22 3:16 6:36 3:02
60%2:54 3:03 4:40 2:39
80%2:11 1:24 3:25 2:31
Percentage boost 20%9.2 %8.2 %18.4 %9.1 %
40%9.1 %8.2 %20.9 %9.2 %
60%7.8 %7.6 %14.7 %8 %
80%5.9 %3.5 %10.8 %7.6 %
Energy consumed 20%2279 mWh1768 mWh4020 mWh2282 mWh
40%2262 mWh1764 mWh4563 mWh2285 mWh
60%1950 mWh1645 mWh3223 mWh1997 mWh
80%1468 mWh761 mWh2360 mWh1896 mWh

It takes the S21 Ultra (Snapdragon) only needs 38 seconds to gain 1% battery level while gaming at a low battery level, which is the quickest time among all tested ultra-premium devices to date (even beating the Oppo Find X3 Pro).

Efficiency (72)

Our Efficiency score comprises two sub-scores, Charge up and Discharge. Charge up is the efficiency of a full charge (how much energy is drained from the wall outlet vs the energy capacity of the battery, as well as the efficiency of the charger and its residual consumption). Discharge is how much current the smartphone drains from the battery when in use (the ratio of battery capacity over autonomy). Better autonomy with a smaller battery means better efficiency.

Charge up

Samsung Galaxy S21 Ultra 5G (Snapdragon)



Nubia RedMagic 7 Pro
Best: Nubia RedMagic 7 Pro (105)

The manufacturer’s recommended 25W charge adapter has a fairly good 85.7% peak efficiency when used with the Snapdragon version, but the Samsung Galaxy S21 Ultra 5G (Exynos) has better peak efficiency with the same charger. However, taking the entire charging system into account (which includes the charger and internal smartphone circuits), both versions of the Samsung have the same nominal efficiency.


The Samsung Galaxy S21 Ultra 5G (Snapdragon) on its charger.



Samsung Galaxy S21 Ultra 5G (Snapdragon)



Apple iPhone 13 Pro
Best: Apple iPhone 13 Pro (121)

The overall power discharge rate of the Samsung Galaxy S21 Ultra 5G (Snapdragon), which earned it a score of 71 points, is better than both the Exynos version’s (51) and the Oppo Find X3 Pro’s (56); but despite the Samsung (Snapdragon)’s slightly better performance in certain specific use cases, there’s simply no comparison between it and the iPhone 12 Pro Max, with its massive tally of 116 points.


It was interesting to compare the battery performance of the Samsung Galaxy S21 Ultra 5G (Snapdragon) against that of its Exynos twin, with the two processors showing noticeably different results across the board. As things stand in our database for ultra-premium devices evaluated thus far, the Snapdragon version’s overall score comes in second behind the Apple iPhone 12 Pro Max; the Oppo Find X3 Pro is third, and the Exynos version of the Galaxy S21 Ultra brings up the rear at more than 20 points below the iPhone (and some 17 points behind the Snapdragon version). While none of its scores reached stratospheric heights, the Samsung Galaxy S21 Ultra 5G (Snapdragon) achieved at least average (and often above-average) results in nearly all tested categories.

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