Say I forget to charge my phone during 20% of the nights. A battery that lasts a single day will fail me very often compared to a two-day battery. Not to mentio

Say I forget to charge my phone during 20% of the nights. A battery that lasts a single day will fail me very often compared to a two-day battery. Not to mention that unlike "dumb" phones, the iPhone won't turn itself on automatically to wake me up in the morning. Also, battery life is measured for "normal use". If you are draining your phone eg. by using it for directions in a friend's car without a charger, then it's suddenly more like 4 hours of battery life.