Battery Life

The Zenfone 8 features a contemporary 4000mAh battery, which considering the size and 169g weight of the phone is actually quite respectable and competes well with other alternatives in the market.

The features that might impact the battery life of the phone are the Snapdragon 888 SoC, less efficient than its predecessor, as well as the 120Hz display which lacks any more advanced power management. The latter aspect of the phone can be quite negative – while the 60Hz mode of the phone has an underperforming base power consumption of 615mW, the 120Hz mode raises this to a rather eye-watering 783mW on a full black screen at minimum brightness.

Anecdotally speaking, I’ve seen vast power regressions on almost all Snapdragon 888 flagship devices this year, all except for Samsung’s S21 Ultra. The Mi 11, Mi 11 Ultra, OnePlus 9 Pro, ROG Phone 5 all exhibit quite bad base power behaviour, and the only difference to the S21 series is that Samsung employs Maxim PMICs and Broadcom WiFi solutions rather than Qualcomm’s own chips. I don’t know if there’s a correlation there or not, but the Zenfone 8 shows similar lacklustre efficiency.

Web Browsing Battery Life 2016 (WiFi)

In the web-browsing test in Auto mode which switches to 90Hz inside of the browser, the Zenfone 8 tracks rather closely to the Zenfone 7. The predecessor has a 25% larger battery, but also has a much larger display. The contemporary comparison to make is the smaller Galaxy S21 which lands ahead of the ZF8 even though it runs at 120Hz mode, and far ahead at 60Hz.

I’ll be updating the article with fixed 120Hz and 60Hz results for the ZF8 in the coming days.

PCMark Work 2.0 - Battery Life 

As noted in the performance section, “Auto” mode actually fixes itself to 60Hz in various applications, such as PCMark. The ZF8 here in its best-case scenario lands actually quite well in the relative positioning, meaning battery life in this mode is relatively competitive.

Again, I’ll be completing the result set with other refresh rate modes in the comings days.

Generally speaking, the Zenfone 8 finds itself in a tough situation when it comes to battery life. The 90Hz and 120Hz modes are really inefficient due to extremely lacklustre base power consumption behaviours. If you were to use your phone at very high brightness levels, the luminance power would vastly overcome that disadvantage and one probably wouldn’t notice the deficit as much, but at lower brightness levels, the phone would last much less than comparative devices.

The conundrum with this situation is that while 60Hz seems to be efficient for the Zenfone 8, it’s also not an as quite good experience when it comes to performance and responsiveness. So either you’ll have to deal with a responsive and inefficient device, or with an adequate battery life but sluggish feeling phone.

GPU Performance Camera - First Impressions


View All Comments

  • Tams80 - Tuesday, May 18, 2021 - link

    The XZ2 isn't really compact. Reply
  • Tams80 - Tuesday, May 18, 2021 - link


    You do realise there are people happy to make that trade-off, even if they are only a small group? And the XZ1 has pretty decent battery life.

    The market is absolutely saturated with large phones, which are popular. That doesn't mean only large phones should exist.

    People like you really grate my gears.
  • Findecanor - Thursday, May 13, 2021 - link

    Agreed. Smartphones do keep getting bigger, but people's hands do not.

    It is also not "the smallest flagship by far". It is about the same size as the iPhone 12/Pro, and weight-wise in-between. And if we compare to flagships from last spring, we got the Samsung Galaxy S20.
  • haukionkannel - Thursday, May 13, 2021 - link

    True… only iPhone 12 mini seems to be allmost compact and no Android versions have been around for years… Reply
  • Linustechtips12#6900xt - Thursday, May 13, 2021 - link

    12 mini or se 2020 Reply
  • Linustechtips12#6900xt - Thursday, May 13, 2021 - link

    as an s10e user, the s10e without a case does very well fit in a single hand thank you very much especially when used with the one-handed feature or just on one ui, in general, that's what one UI was made for to be better on bigger phone and make them easier to use even though s10e is compact it is a very decent phone. Reply
  • inperfectdarkness - Sunday, May 16, 2021 - link

    XZ2 Compact > XZ1 Compact, imho. Damn shame Sony doesn't care diddly squat to make another 5" phone. Everything is 6" now. Reply
  • prophet001 - Thursday, May 13, 2021 - link

    Anybody know a good 4g phone that's like the size of a Blackberry Bold. I like having it in my pocket and can't find anything that is that size and still has email, web etc.

  • hemedans - Thursday, May 13, 2021 - link

    sony xperia xz1 compact
    bold 115cm
    xz1c 128cm

    bold 66cm
    xz1c 65cm

    bold 10.5cm
    xz1c 9.3 cm

    xz1c will be narrow and compact but a little bit taller.
  • inperfectdarkness - Sunday, May 16, 2021 - link

    Bold: 115 x 66 x 10.5 mm (4.53 x 2.60 x 0.41 in)
    XZ1 Compact: 129 x 65 x 9.3 mm (5.08 x 2.56 x 0.37 in)
    XZ2 Compact: 135 x 65 x 12.1 mm (5.31 x 2.56 x 0.48 in)

    Those are the closest you'll find outside of something pitifully small and unusable--which is pretty much every phone in the < 4" size.

    The XZ2 Compact - international version - can handle dual SIM cards or SIM + SD.

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