As a battery ages it's capacity decreases. That's noticeable in that it will carry a load for less time, and the voltage it can sustain decreases. On most pho

As a battery ages it's capacity decreases. That's noticeable in that it will carry a load for less time, and the voltage it can sustain decreases. On most phones you realize that when an old phone goes from 15%, you do something CPU intensive and the phone dies seconds later. So it's reasonable to lower the peak power use on older batteries to lengthen battery life and make it more stable. Generally battery life increases when you are gentle. Charge slowly (which results in lower temps), avoid charging over 90% or discharging below 10%, and decrease the peak loads.