There's plenty of people reporting a higher than expected battery drain on the Zenfone 8, and while we just have to assume the cost of using an 888 snapdragon, there seems to be an issue with the system itself, causing a high idle battery drain. The phone just never gets into deep doze, no matter how much times it spends turned off. This causes maybe twice the battery drain what it should use while doing nothing. I'm confident in this being an issue with ZenUI itself, since no amount of wakelocks from apps would cause a literal 0 seconds of deep doze, plus I see no wakelocks or strange behaviour from any apps in either the system battery information or GSam Battery Monitor (an app that's always worked well for me in this regard). I'm uploading to snapshots from GSam, one from the Zenfone that I just took after leaving the phone alone for 2 and a half hours, and one from my old s10e for comparison. As you can see, the Zenfone just doens't ever enter deep doze, leading, as of this moment, to a 0.7% per hour battery drain while doing nothing, a drain that's easily twice as high as it should be with a 4000 mah battery (for reference the s10e drains about 0.4-0.5% per hour with an older 3000 mah battery) If we could get a way of fixing this, it'd go a long way to stretch the battery use of the phone.
Agreed, don't think the updates helped the battery situation as i initially still had bad battery after updating only when turning off all optimisations and letting the phone run as my message above i started to see dramatic increase in battery life and standy time
With last update standby drain is much better. But the problem is a "4000mAh" battery. Meybe it is that much on paper, but not in reality. Accubattery shows 3550mAh and many people comment that it measures incorrecly. Well, i fill 58% battery in one hour with 2A charger (also enebled ultra steady charging, which limit to 2A). So, 2000mA in a hour imput filled 58%, when it should max 50%. (it should few % less because charging is not 100% efficient, that is why it heats up during charging) Some say, Asus left some reserve when battery degrades. Battery goes up to 4,45V after 85%!!! I have nevere seen so high voltages used on Lithium battery. I dont see any reserve.