The Asus Zenfone 8 made its appearance in May 2021. Packed with features, it belongs to our Premium ($600-$799) segment. Let’s take a look at some of its key battery test results.
Key specifications:
- Battery capacity: 4000 mAh
- 30W charger
- 5.9-inch, 1080 x 2400, 120 Hz OLED display
- Qualcomm Snapdragon 888 5G chipset
- Tested ROM / RAM combination: 128 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
Scoring
Sub-scores and attributes included in the calculations of the global score.
Asus Zenfone 8
102
battery
92
Honor X7b
Best: Honor X7b (221)
91
Samsung Galaxy M51
Best: Samsung Galaxy M51 (195)
95
Samsung Galaxy M51
Best: Samsung Galaxy M51 (198)
110
Realme GT Neo 5 (240W)
Best: Realme GT Neo 5 (240W) (224)
111
Realme GT Neo 5 (240W)
Best: Realme GT Neo 5 (240W) (212)
132
Nubia RedMagic 7 Pro
Best: Nubia RedMagic 7 Pro (205)
107
Apple iPhone 14 Pro
Best: Apple iPhone 14 Pro (194)
Key performances
These key points are derived from the lab measurements during testing and do not figure into the overall score. The lab measurements, however, are used for the overall score.
3h08 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.
Position in Global Ranking
145
th
3. Honor Magic6 Lite (5800 mAh)
156
8. Honor Magic6 Lite (5300 mAh)
150
9. Realme GT Neo 5 (240W)
147
16. Samsung Galaxy S23 Ultra
142
26. Samsung Galaxy A15 LTE
137
27. Apple iPhone 13 Pro Max
136
27. Xiaomi Redmi Note 12 Pro 5G
136
37. Apple iPhone 15 Pro Max
134
37. Xiaomi Redmi Note 11 Pro 5G
134
41. Apple iPhone 14 Pro Max
133
41. Vivo X60 Pro 5G (Snapdragon)
133
41. Xiaomi Redmi Note 11S 5G
133
48. Xiaomi Redmi Note 12 5G
132
48. Xiaomi Redmi Note 10S
132
56. Oppo Reno6 Pro 5G (Snapdragon)
130
56. Samsung Galaxy S24 Ultra
130
58. Samsung Galaxy A34 5G
129
58. Samsung Galaxy A23 5G
129
58. Xiaomi Redmi Note 12 Pro+ 5G
129
58. Xiaomi Redmi Note 10 Pro
129
66. Samsung Galaxy A15 5G
127
75. Samsung Galaxy A13 5G
125
83. Apple iPhone 12 Pro Max
121
83. Samsung Galaxy A55 5G
121
86. Xiaomi Redmi Note 13 Pro 5G
120
86. Xiaomi Redmi Note 10 5G
120
98. Samsung Galaxy A14 5G
117
105. Crosscall Stellar-X5
115
109. Samsung Galaxy Z Fold5
114
109. Xiaomi Mi 10T Pro 5G
114
114. Samsung Galaxy A54 5G
113
118. Motorola Moto G62 5G
112
122. Motorola Moto G9 Power
111
122. Samsung Galaxy S21 Ultra 5G (Snapdragon)
111
122. Xiaomi Redmi Note 13 Pro Plus 5G
111
128. Samsung Galaxy Z Flip5
109
128. Samsung Galaxy S24+ (Exynos)
109
132. Samsung Galaxy S21 5G (Snapdragon)
108
136. Samsung Galaxy S24 (Exynos)
107
136. Xiaomi Mi 11 Lite 5G
107
138. Samsung Galaxy A52 5G
106
142. Samsung Galaxy S22 Ultra (Snapdragon)
103
145. Motorola moto g34 5G
102
149. Samsung Galaxy S23 FE
101
149. Samsung Galaxy A35 5G
101
151. Samsung Galaxy S21 5G (Exynos)
100
151. Xiaomi Redmi 10 2022
100
156. Apple iPhone 13 mini
99
156. Samsung Galaxy Z Fold4
99
156. Vivo X80 Pro (Snapdragon)
99
161. Motorola Edge 30 Pro
98
161. Samsung Galaxy S22 Ultra (Exynos)
98
165. Samsung Galaxy A33 5G
96
168. Samsung Galaxy Z Flip4
95
168. Samsung Galaxy S22+ (Exynos)
95
168. Samsung Galaxy A53 5G
95
173. Xiaomi Redmi Note 13 5G
94
175. Apple iPhone 12 mini
93
175. Samsung Galaxy S21 Ultra 5G (Exynos)
93
178. Samsung Galaxy Z Fold3 5G
92
179. Motorola moto g54 5G
90
179. Samsung Galaxy S22 (Snapdragon)
90
185. Apple iPhone SE (2022)
84
187. Samsung Galaxy S21 FE 5G (Snapdragon)
82
191. Samsung Galaxy S22 (Exynos)
75
Position in Premium Ranking
27
th
2. Vivo X60 Pro 5G (Snapdragon)
133
4. Oppo Reno6 Pro 5G (Snapdragon)
130
23. Samsung Galaxy S21 5G (Snapdragon)
108
24. Samsung Galaxy S24 (Exynos)
107
29. Samsung Galaxy S21 5G (Exynos)
100
36. Samsung Galaxy S22 (Snapdragon)
90
38. Samsung Galaxy S21 FE 5G (Snapdragon)
82
40. Samsung Galaxy S22 (Exynos)
75
Pros
- Good power management at night
- Charging time from 0% to 80% is acceptable in its segment
- Residual power drain kept under control
Cons
- No wireless charger
- Disappointing in music and video streaming
- Performance in on the go tests, especially for calling and camera
Despite having specs that are similar to its competitors in this review, the Asus Zenfone 8 lags a bit behind in most tested categories.
We compared the Asus Zenfone 8’s performance with two other devices in our Premium segment, the OnePlus 9 and the Samsung Galaxy S21 5G (Snapdragon); battery capacity, tested charger, display type, and resolution, and processor specifications for all three devices are shown in the table below.
|
Asus Zenfone 8 |
OnePlus 9 |
Samsung Galaxy S21 5G (Snapdragon) |
Battery capacity |
4000 mAh |
4500 mAh |
4000 mAh |
Charger
Wireless |
30W
No
|
65W
15W |
25W (not included)
15W
|
Display type |
OLED |
OLED |
OLED |
Display resolution |
1080 x 2400 |
10800 x 2400 |
1080 x 2400 |
Chipset |
Qualcomm Snapdragon 888 5G |
Qualcomm Snapdragon 888 5G |
Qualcomm Snapdragon 888 5G |
Autonomy (51)
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.
66h
Light Usage
Active: 2h30/day
45h
Moderate Usage
Active: 4h/day
27h
Intense Usage
Active: 7h/day
The Asus Zenfone 8 comes in behind its rivals in all three of our autonomy test categories. Further, its battery gauge is not especially accurate, since when the battery gauge shows 20% power remaining, there is really only 17.9% left.
Position in Global Ranking
Battery Life (moderate)
166
th
7. Samsung Galaxy A15 LTE
78h
8. Honor Magic6 Lite (5800 mAh)
77h
10. Honor Magic6 Lite (5300 mAh)
77h
16. Xiaomi Redmi Note 11S 5G
72h
22. Xiaomi Redmi Note 10 5G
70h
26. Apple iPhone 15 Pro Max
69h
27. Samsung Galaxy A15 5G
69h
29. Samsung Galaxy A13 5G
69h
31. Apple iPhone 13 Pro Max
68h
33. Xiaomi Redmi Note 10 Pro
67h
34. Samsung Galaxy S23 Ultra
67h
35. Xiaomi Redmi Note 12 5G
67h
41. Samsung Galaxy A34 5G
65h
43. Apple iPhone 14 Pro Max
65h
46. Samsung Galaxy A23 5G
64h
52. Motorola Moto G9 Power
64h
55. Xiaomi Redmi Note 12 Pro 5G
62h
56. Samsung Galaxy A14 5G
62h
57. Xiaomi Redmi Note 11 Pro 5G
62h
58. Xiaomi Redmi Note 10S
61h
61. Samsung Galaxy A54 5G
60h
79. Samsung Galaxy A55 5G
57h
86. Samsung Galaxy S24 Ultra
56h
88. Samsung Galaxy A52 5G
56h
89. Xiaomi Redmi Note 13 Pro 5G
56h
91. Xiaomi Redmi Note 12 Pro+ 5G
55h
92. Realme GT Neo 5 (240W)
55h
101. Xiaomi Mi 11 Lite 5G
54h
102. Samsung Galaxy Z Fold5
54h
106. Motorola moto g54 5G
53h
108. Nubia RedMagic 7 Pro
53h
114. Motorola Edge 20 Pro
52h
124. Xiaomi Mi 10T Pro 5G
51h
128. Vivo X60 Pro 5G (Snapdragon)
51h
129. Xiaomi Redmi Note 13 5G
50h
135. Samsung Galaxy S21 5G (Snapdragon)
50h
137. Samsung Galaxy A35 5G
49h
138. Samsung Galaxy A53 5G
49h
143. Samsung Galaxy S24+ (Exynos)
49h
145. Xiaomi Redmi Note 13 Pro Plus 5G
49h
146. Samsung Galaxy S24 (Exynos)
49h
147. Apple iPhone 12 Pro Max
49h
148. Samsung Galaxy Z Fold4
49h
150. Samsung Galaxy S21 Ultra 5G (Snapdragon)
48h
152. Oppo Reno6 Pro 5G (Snapdragon)
48h
155. Motorola Edge 30 Pro
47h
156. Samsung Galaxy A33 5G
47h
157. Samsung Galaxy S22 Ultra (Snapdragon)
47h
158. Samsung Galaxy S23 FE
47h
160. Samsung Galaxy Z Flip5
46h
161. Samsung Galaxy S21 5G (Exynos)
46h
163. Nubia RedMagic 6 Pro
46h
168. Samsung Galaxy S22 Ultra (Exynos)
44h
171. Vivo X80 Pro (Snapdragon)
43h
173. Samsung Galaxy Z Fold3 5G
43h
174. Samsung Galaxy Z Flip4
42h
176. Samsung Galaxy S21 Ultra 5G (Exynos)
41h
178. Apple iPhone 13 mini
41h
179. Apple iPhone 12 mini
40h
181. Samsung Galaxy S22+ (Exynos)
40h
182. Samsung Galaxy S22 (Snapdragon)
39h
185. Samsung Galaxy S21 FE 5G (Snapdragon)
38h
188. Apple iPhone SE (2022)
37h
190. Samsung Galaxy S22 (Exynos)
35h
Position in Premium Ranking
Battery Life (moderate)
30
th
18. Vivo X60 Pro 5G (Snapdragon)
51h
20. Samsung Galaxy S21 5G (Snapdragon)
50h
23. Samsung Galaxy S24 (Exynos)
49h
25. Oppo Reno6 Pro 5G (Snapdragon)
48h
27. Samsung Galaxy S21 5G (Exynos)
46h
35. Samsung Galaxy S22 (Snapdragon)
39h
37. Samsung Galaxy S21 FE 5G (Snapdragon)
38h
40. Samsung Galaxy S22 (Exynos)
35h
Stationary
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 lasted 53 hours 37 minutes, which is 3 to 4 hours less than its rivals, but still offers more than 2 days of autonomy. It manages night dischage well, losing only 2%, compared to the OnePlus 9’s loss of 2.33%.
Typical Usage Scenario discharge curves
On the go
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 Asus battery struggles in on the go tests, especially when calling and using its camera, though it performs almost as well as its rivals for social apps on the go.
Autonomy for on the go use cases (full charge)
Calibrated
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.
Although the Zenfone 8 is well optimized with its screen off in idle mode, it does not fare well against the competition. All video test cases drain its battery quickly, though it manages to do nearly as well as the OnePlus and Samsung when gaming.
Autonomy for calibrated use cases (full charge)
Charging (75)
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.
Unsurprisingly, the OnePlus 9 with its 65W charger is far ahead of both the Asus and the Samsung in our charging tests.
Power consumption and battery level during full charge
Full charge
Black Shark 5 Pro
Best: Black Shark 5 Pro (121)
It takes 1 hour 51 minutes to fully charge the Asus Zenfone 8 with its 30W charger, which is a bit slower than the Samsung Galaxy S21 5G (Snapdragon) with its 25W charger. The difference is that Asus decreases the charging power at around 75% capacity to conserve battery longevity, while the Samsung waits to slow charging until it gets to 87%. The OnePlus 9 takes only 33 minutes 32 seconds to achieve a full charge.
Position in Global Ranking
Charging Time 0-80%
91
st
1. Realme GT Neo 5 (240W)
0h08
23. Oppo Reno6 Pro 5G (Snapdragon)
0h22
30. Xiaomi Redmi Note 12 Pro+ 5G
0h24
31. Vivo X80 Pro (Snapdragon)
0h24
36. Xiaomi Redmi Note 13 Pro Plus 5G
0h26
56. Xiaomi Redmi Note 13 Pro 5G
0h31
61. Xiaomi Redmi Note 12 Pro 5G
0h33
68. Samsung Galaxy S23 Ultra
0h37
69. Samsung Galaxy S22+ (Exynos)
0h37
73. Samsung Galaxy S24 Ultra
0h38
74. Xiaomi Redmi Note 11 Pro 5G
0h38
77. Samsung Galaxy S22 Ultra (Snapdragon)
0h39
78. Samsung Galaxy S22 Ultra (Exynos)
0h40
79. Vivo X60 Pro 5G (Snapdragon)
0h40
83. Samsung Galaxy S24+ (Exynos)
0h42
88. Xiaomi Redmi Note 12 5G
0h44
93. Samsung Galaxy S21 Ultra 5G (Snapdragon)
0h46
94. Honor Magic6 Lite (5300 mAh)
0h47
98. Samsung Galaxy Z Flip5
0h48
99. Samsung Galaxy S21 5G (Exynos)
0h48
100. Samsung Galaxy S24 (Exynos)
0h49
101. Samsung Galaxy S21 5G (Snapdragon)
0h49
103. Xiaomi Redmi Note 11
0h49
104. Samsung Galaxy S23 FE
0h49
106. Samsung Galaxy A23 5G
0h49
109. Samsung Galaxy S22 (Snapdragon)
0h50
111. Samsung Galaxy Z Fold5
0h51
112. Samsung Galaxy S22 (Exynos)
0h51
113. Samsung Galaxy A35 5G
0h51
115. Apple iPhone SE (2022)
0h51
115. Samsung Galaxy A34 5G
0h51
117. Samsung Galaxy S21 Ultra 5G (Exynos)
0h51
118. Xiaomi Redmi Note 10
0h52
119. Xiaomi Redmi Note 10S
0h52
120. Apple iPhone 12 mini
0h52
122. Samsung Galaxy A55 5G
0h52
123. Samsung Galaxy A54 5G
0h52
125. Xiaomi Redmi Note 13 5G
0h53
126. Samsung Galaxy S21 FE 5G (Snapdragon)
0h53
129. Samsung Galaxy A33 5G
0h54
129. Xiaomi Redmi Note 11S 5G
0h54
131. Samsung Galaxy A15 LTE
0h54
132. Samsung Galaxy A15 5G
0h54
133. Apple iPhone 15 Plus
0h54
134. Xiaomi Redmi Note 10 Pro
0h55
135. Apple iPhone 15 Pro Max
0h56
136. Samsung Galaxy Z Fold4
0h56
137. Honor Magic6 Lite (5800 mAh)
0h56
139. Samsung Galaxy A53 5G
0h57
140. Samsung Galaxy Z Flip4
0h57
141. Apple iPhone 13 mini
0h57
142. Apple iPhone 12 Pro Max
0h57
143. Samsung Galaxy Z Fold3 5G
0h57
149. Apple iPhone 13 Pro Max
1h01
153. Apple iPhone 14 Plus
1h03
159. Apple iPhone 14 Pro Max
1h06
165. Motorola moto g34 5G
1h12
167. Samsung Galaxy A52 5G
1h15
169. Crosscall Stellar-X5
1h20
173. Xiaomi Redmi Note 10 5G
1h22
175. Xiaomi Redmi 10 2022
1h25
178. Motorola Moto G62 5G
1h26
179. Motorola moto g54 5G
1h26
180. Samsung Galaxy A14 5G
1h28
181. Samsung Galaxy A13 5G
1h30
188. Motorola Moto G9 Power
1h53
Position in Premium Ranking
Charging Time 0-80%
24
th
10. Oppo Reno6 Pro 5G (Snapdragon)
0h22
21. Vivo X60 Pro 5G (Snapdragon)
0h40
26. Samsung Galaxy S21 5G (Exynos)
0h48
27. Samsung Galaxy S21 5G (Snapdragon)
0h49
28. Samsung Galaxy S24 (Exynos)
0h49
29. Samsung Galaxy S22 (Snapdragon)
0h50
31. Samsung Galaxy S22 (Exynos)
0h51
33. Samsung Galaxy S21 FE 5G (Snapdragon)
0h53
Quick boost
Realme GT Neo 3
Best: Realme GT Neo 3 (111)
The Asus Zenfone 8 provides an average of more than 3 hours of additional autonomy with a five-minute charge. This is better than the Samsung’s 2 hours 34 minutes, but the OnePlus 9 provides a whopping near-7 hours.
|
| Asus Zenfone 8 | OnePlus 9 | Samsung Galaxy S21 5G (Snapdragon) |
Autonomy boost (hh:mm) | 20% | 3:19 | 8:26 | 2:38 |
40% | 3:17 | 5:59 | 2:45 |
60% | 2:33 | 5:28 | 2:09 |
80% | 1:27 | 4:02 | 1:57 |
Percentage boost | 20% | 9.9 % | 23 % | 7.4 % |
40% | 9.8 % | 16.3 % | 7.7 % |
60% | 7.6 % | 14.9 % | 6 % |
80% | 4.4 % | 11 % | 5.5 % |
Energy consumed | 20% | 1964 mWh | 4923 mWh | 1466 mWh |
40% | 1944 mWh | 3491 mWh | 1528 mWh |
60% | 1512 mWh | 3188 mWh | 1195 mWh |
80% | 864 mWh | 2354 mWh | 1088 mWh |
Efficiency (75)
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.
Although the Zenfone 8 just edged out the OnePlus in discharge efficiency, it was quite a ways behind the Samsung, and both the OnePlus and Samsung did better than the Asus device in charge up efficiency.
Charge up
Nubia RedMagic 7 Pro
Best: Nubia RedMagic 7 Pro (105)
The Asus Zenfone 8 comes in last among the three devices for charge up and charger efficiency; that said, its charger efficiency is not bad for its segment.
Discharge
Apple iPhone 13 Pro
Best: Apple iPhone 13 Pro (121)
The Zenfone 8 achieves slightly better results than the OnePlus 9 in discharge efficiency, particularly in gaming and video playback. The Samsung is a better-optimized device than either the Asus or the OnePlus.
Conclusion
The Asus Zenfone 8 struggles to provide a good autonomy and charging experience, but does a decent job managing residual power drain and power consumption at night.
DXOMARK encourages its readers to share comments on the articles. To read or post comments, Disqus cookies are required. Change your Cookies Preferences and read more about our Comment Policy.