" 100 % " is a matter of definition. It's planned obsolescence, simply put. What is generally agreed upon as " 100 % " is the voltage that makes the capacity dr

" 100 % " is a matter of definition. It's planned obsolescence, simply put. What is generally agreed upon as " 100 % " is the voltage that makes the capacity drop to ~ 80 % after 300~350 full charge cycles. This means your device battery is at end-of-life after a full year of daily full charge cycles. Why we've defined it as such, I don't know. If we wanted our batteries to live longer we could simply change the definition of " 100 % " indicate 600 full charge cycles. In practice it would mean something like dropping the peak capacity voltage from 4.20 Volts to 4.10 Volts.