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Samsung Galaxy S21 5G (Snapdragon) Battery test: Good efficiency

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

Coming to market in January 2021, the Samsung Galaxy S21 5G (Snapdragon)’s launch price puts it into the Premium ($600-$799) segment. Like its Exynos twin, it comes with a number of attractive features, including a triple-camera setup. Our team of battery experts recently put it through our DXOMARK testing protocol; what follows is a summary of the results.

Key specifications:

  • Battery capacity: 4000 mAh
  • 25W (charger not included)
  • 6.2-inch, 1080 x 2400, 120 Hz OLED display
  • Qualcomm Snapdragon 888 5G (5 nm) chipset
  • Tested RAM / storage combination: 8 GB + 128 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 5G (Snapdragon)














Key performances

Charging Time
2 days 2h
Battery life
Charging Time
80% Charging time
Charging Time
Full charging time
Quick Boost
2h34 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.


  • Good efficiency both during charge up and when in use
  • Charger has very low residual power drain both during trickle charging and when phone is not connected
  • Wireless charging is convenient


  • Below-average charging speed
  • Above-average battery drain when screen is off in idle, music streaming and calls

The Samsung Galaxy S21 5G (Snapdragon) racks up an above-average overall score in its segment, beating its Exynos sibling and doing largely better than the two competitor devices in this review, the Apple iPhone 12 mini and the Google Pixel 5, due primarily to better performance in our autonomy tests. The table below shows the battery capacity, charger, display type and resolution, and processor specifications for the Snapdragon version of the S21 5G and for the Apple and Google devices.

 Samsung Galaxy S21 (Snapdragon)

Apple iPhone 12 mini Google Pixel 5
Battery capacity (mAh)


2227 4080


20W 18W
Wireless charging




Display type, max Hz



Display resolution

1080 x 2400 1080 x 2340

1080 x 2340


Qualcomm Snapdragon 888 5G A14 Bionic

Qualcomm Snapdragon 765 5G

Autonomy (55)

How long a battery charge lasts depends not only on battery capacity, but also 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

Among its competitors, the Samsung Galaxy S21 5G (Snapdragon) puts in a good performance, with a score that is above average for its segment, but just under the average for the entire Battery protocol database.

In terms of linearity, the battery percentage indicator on the Samsung S21 5G (Snapdragon) is very accurate and reliable.


Samsung Galaxy S21 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. 

In our TUS tests, the Samsung Galaxy S21 5G (Snapdragon) lasts more than 56 hours, which is both above average for its segment and longer than its rivals, with the Apple iPhone12 mini coming in at 43 hours 22 minutes and the Google Pixel 5 lasting for 47 hours 30 minutes. However, the Samsung’s results are around four hours less than the average for all tested devices in our database.

Typical Usage Scenario discharge curves

On the go

Samsung Galaxy S21 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 Samsung Galaxy S21 5G (Snapdragon)’s performance is very close to that of its rivals except for calling, where it did noticeably better than the Apple and Google devices (though only around the average for other devices in its price range).

Autonomy for on the go use cases (full charge)


Samsung Galaxy S21 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.

Both the Samsung and Google devices beat the Apple iPhone12 mini across the board, and while the Samsung takes the lead in 4G streaming and gaming tests, the Google Pixel 5 is ahead of the Samsung for 3G calling and video playback.

Autonomy for calibrated use cases (full charge)

Charging (73)

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

Full charge

Samsung Galaxy S21 5G (Snapdragon)



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

The Samsung Galaxy S21 5G went from 0 to an 80% in 48 minutes 34 seconds, which is better than its rivals, but it needed more than 45 minutes to charge from 80% to full capacity. Our engineers note that its charger never reached its maximum power of 25W.

While it takes the Snapdragon version of the S21 5G one hour longer to achieve a 100% charge via wireless charging, it is still a convenient option.

Time to full charge
Time to full charge

Quick boost

Samsung Galaxy S21 5G (Snapdragon)



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

The Samsung Galaxy S21 5G (Snapdragon) provides more than two hours of autonomy when charged at 20%, 40%, 60%, and 80%, beating both the Apple and Google devices for longevity following a 5-minute charge. Even so, the Samsung’s performance is below average for its segment.

Samsung Galaxy S21 5G (Snapdragon) Apple iPhone 12 mini Google Pixel 5
Autonomy boost (hh:mm) 20%2:38 2:43 2:16
40%2:45 2:31 2:16
60%2:09 1:53 1:46
80%1:57 1:20 1:13
Percentage boost 20%7.4 %9.5 %6.9 %
40%7.7 %8.8 %6.9 %
60%6 %6.6 %5.4 %
80%5.5 %4.7 %3.7 %
Energy consumed 20%1466 mWh1205 mWh1654 mWh
40%1528 mWh1119 mWh1656 mWh
60%1195 mWh838 mWh1294 mWh
80%1088 mWh591 mWh894 mWh

Efficiency (89)

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 to autonomy). Better autonomy with a smaller battery means better efficiency.

Charge up

Samsung Galaxy S21 5G (Snapdragon)



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

Compared to its rivals, the S21 5G (Snapdragon) charging system is well designed, providing better charge and adapter efficiency, and better management of residual power drain.


Samsung Galaxy S21 5G (Snapdragon)



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

The Samsung Galaxy S21 5G (Snapdragon) had good efficiency in all screen-on tests (gaming, video streaming, video playback), though the iPhone 12 mini is much more efficient, and can last almost as long with a much smaller 2227 mAh battery.


The Samsung S21 5G (Snapdragon) achieves decent autonomy overall, but it would have been nice to pair that with faster charging, which is quite common at this price range.

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