I am using my new Asus Zenfone 8 Flip a few days. I am disappointed. I use it normally as all my other phones, a bit of videos, a bit of photos, browsing youtube. Half a day and the battery is flat. The screen was 60 Hz. Battery settings: Optimal/Dynamic. Double checked if there is any draining app - nothing found. For its 5000 mAh, it does not perform well. I wonder how people paying that money and then walking around with power banks. All my previous phones were in the range of 5000-6000 mAh - but were much much more efficient in terms of energy consumption.
I agree with you. Phone with this big battery should easily last a day but it's really a struggle to do so. I only get about 3 to 5 hours of sot and battery is flat. I think the screen-off battery drain is main problem because when i downloaded accubattery, it showed that this phone will only last 24 hours if the screen is off all the time. On comparison my dad's motorola, which has 6000mah battery, had 56% battery left. It had 3 hours of sot at that time and it was charged 1 day and 18 hours ago.
This issue has to be adressed because the battery was a big selling point to me and it has been a really big dissapointment so far.