> <i>The biggest motivation for US adult smartphone owners to upgrade their devices is longer battery life (61%)...</i><p>Battery replacements are a thing. They're apparently not a common thing, unfortunately, because that might impact new phone sales... and even on devices where it's trivial, people don't seem to do it. A decade ago or so I was doing a lot of Nexus 5 battery swaps for people because one of the battery OEMs was shipping junk and the batteries were shot in a year.<p>I really wish OEMs would put bigger batteries in phones. It improves everything. Not only do you get longer initial battery life, you can handle far more "battery aging" before things stop working right. You still have a day's battery life (which I expect is what most people actually mean - they want their phone to last the day without thinking about it) even with capacity loss, and a larger battery can have more internal resistance increase (another factor of battery aging) before it sags too badly under the load to keep voltage up.<p>Based on the fact that easily 90+% of phones I see in the wild have cases on them, physical size and thickness isn't a big factor (and those newer folding screen devices are massive when folded). Another few mm doesn't matter when phones live in purses, men's pockets, or jackets.<p>... or just go back to a modern flip phone sort of device, get a week and a half battery life, and stop worrying about remembering to charge your phone. ;)