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.