I'm not sure I or really anyone actually wants a 2 day battery life.
Like, we can do that on smartphones right now but users have signaled that the 1 day device is fine for them, notably because of the human gap.
You know the gap.
If you charge your phone every night it becomes a habit tied to your daily routine.
If you were to charge your phone every other night, you might lose track of what day you are on, not charge it and then the perceived battery life experience is worse. This is why smart watches with 3-4 days of battery have not prevailed over those with one heavy day of battery. They are annoying to know what day you are on so you might just charge it every night and if you do, the platform is trading off so much power that the experience is worse.
Plus, then you have to carry 2 days worth of battery or have half the power envelope as a laptop with one day. the concept all sounds great but the reality of people using things really has honed in on the fact that these things need to fit into habit and use cases that make sense.
Why are you assuming you need to charge a 2-day device every other day? You charge it every night, and in exchange you make it through heavy use days, late nights, and the times you forget to charge it. I had a 2-day phone and downgraded to a 1-day phone and my phone now dies on me much more often, including in each of those scenarios, and looking at the battery level and charging have become a bigger part of my life.
You know the gap.
If you charge your phone every night it becomes a habit tied to your daily routine.
If you were to charge your phone every other night, you might lose track of what day you are on, not charge it and then the perceived battery life experience is worse. This is why smart watches with 3-4 days of battery have not prevailed over those with one heavy day of battery. They are annoying to know what day you are on so you might just charge it every night and if you do, the platform is trading off so much power that the experience is worse.
Plus, then you have to carry 2 days worth of battery or have half the power envelope as a laptop with one day. the concept all sounds great but the reality of people using things really has honed in on the fact that these things need to fit into habit and use cases that make sense.