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Asus Zenfone 8 Flip Battery test: Average autonomy

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

The Asus Zenfone 8 Flip appeared on the market in May 2021 and fits into our Premium ($600-$799) segment. It comes with a triple-camera setup, including a 64 MP main camera that flips open (hence the name). Here are some of its key test results in our Battery protocol.

Key specifications:

  • Battery capacity: 5000 mAh
  • 30W charger
  • 6.67-inch, 1080 x 2400, 90 Hz OLED display
  • Qualcomm Snapdragon 888 5G (5 nm) chipset
  • Tested ROM / RAM combination: 256 GB + 8 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.

Asus Zenfone 8 Flip














Key performances

Charging Time
2 days 1h
Battery life
Charging Time
80% Charging time
Charging Time
Full charging time
Quick Boost
2h41 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.


  • More than 2 days of autonomy with moderate use
  • Good autonomy for calibrated 3G calling and gaming


  • Poor charging experience compared to other devices in its segment
  • High power consumption when streaming video
  • No wireless charging

The Asus Zenfone 8 Flip has the largest battery capacity (5000 mAh) in this comparison. Coming with a 30W charger, it has the same global score as the Samsung Galaxy S21 5G (Exynos); but both the Asus and Samsung devices come in behind the OnePlus 9, thanks to its outstanding charging experience and better efficiency.

The table below shows the battery capacity, tested charger, display type and resolution, and processor specifications for all three of these Premium devices.

Asus Zenfone 8 Flip Samsung Galaxy S21 5G (Exynos) OnePlus 9
Battery capacity 5000 mAh 4000 mAh 4500 mAh




25W (not included)




Display resolution 1080 x 2400 1080 x 2400 1080 x 2400
Chipset Qualcomm Snapdragon 888 5G 5 nm Exynos 2100 5 nm Qualcomm Snapdragon 888 5G 5 nm

Autonomy (55)

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 Asus Zenfone 8 Flip comes out ahead of the Samsung Galaxy S21 5G (Exynos) but remains behind the OnePlus 9 in our Autonomy tests.


Asus Zenfone 8 Flip



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 Asus Zenfone 8 Flip lasted 56 hours 34 minutes in our TUS — five hours longer than the Samsung, but 49 minutes less than the OnePlus. The Asus device lost 2% of its battery charge during the night, which is better than its competitors.

Typical Usage Scenario discharge curves

On the go

Asus Zenfone 8 Flip



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.

Although it put in an average performance for social apps, the Asus device did not do well when using its camera and GPS navigation and when calling on the go.

Autonomy for on the go use cases (full charge)


Asus Zenfone 8 Flip



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 Zenfone 8 Flip did well for 3G call, gaming, and idle management in our calibrated tests, considerably better than its rivals. Both the Asus and the OnePlus did better than the Samsung Galaxy S21 5G (Exynos), which brought up the rear in nearly all calibrated tests.

Autonomy for calibrated use cases (full charge)

Charging (68)

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 zero 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

Full charge

Asus Zenfone 8 Flip



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

Power consumption and battery level during full charge

The Asus Zenfone 8 Flip needs 2 hours 19 minutes to go from completely empty to completely full. This is much slower than the OnePlus 9, whose 65W charger fills its 4500 mAh battery in only 39 minutes.

Two points worth noting is that (1) unlike its competitors, the Asus does not support wireless charging; and (2) its 30W charger actually charges at 25W.

Time to full charge

Quick boost

Asus Zenfone 8 Flip



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

By plugging in the Zenfone 8 Flip for 5 minutes with less than 50% of battery charge remaining, users will gain more than 2.5 hours autonomy. These results are almost the same as the Samsung phone, but far behind the OnePlus 9’s gain of 6 hours.

Asus Zenfone 8 Flip Samsung Galaxy S21 5G (Exynos) OnePlus 9
Autonomy boost (hh:mm) 20%2:51 2:33 8:26
40%2:39 2:36 5:59
60%2:21 2:05 5:28
80%1:18 2:01 4:02
Percentage boost 20%8.2 %7.4 %23 %
40%7.6 %7.6 %16.3 %
60%6.7 %6.1 %14.9 %
80%3.7 %5.9 %11 %
Energy consumed 20%1998 mWh1458 mWh4923 mWh
40%1857 mWh1487 mWh3491 mWh
60%1645 mWh1192 mWh3188 mWh
80%911 mWh1148 mWh2354 mWh

Efficiency (68)

The DXOMARK power efficiency score consists of two sub-scores, Charge up and Discharge rate, both of which combine data obtained during robot-based typical usage scenario testing, outdoor mobility testing, charging evaluation, and power measurements, and then take into consideration the device’s battery capacity.

The Asus Zenfone 8 Flip showed good performance in some specific tests, but lagged behind its rivals overall.

Charge up

Asus Zenfone 8 Flip



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

The Asus Zenfone 8 Flip has a fairly efficient charging system and charger, but less efficient than its rivals in both cases, as it has higher residual power drain when unplugged than the Samsung and OnePlus.


Asus Zenfone 8 Flip



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

The Asus device had very high consumption for video streaming, but considerably lower discharge for gaming, 3G call, and idle management than the competition.


The Asus Zenfone 8 Flip does not offer a very good charging experience, but provides more than 2 days of autonomy with moderate use.

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