Flagship phone drains by mid afternoon despite all day battery claim.

[AdamYW]

I recently upgraded to a flagship smartphone, and despite the manufacturer's claims of all-day battery life, I'm finding I need to recharge by mid-afternoon under my normal usage, which involves a lot of mobile data, GPS, and video calls. I've already turned down screen brightness and disabled unnecessary background refresh, but the drain is still significant. For other power users, what specific settings or habits have you found most effective for genuinely extending battery life on modern phones, and are there any reliable external battery packs or charging technologies you'd recommend for topping up quickly without degrading the internal battery over time?