My battery is 1.5 years old.
Amaron Hi-Life.
I believe this battery should last >2 years
ya it can last 2 yrs if u are not using parking mode
battery will degrade as time goes by
the power in the battery will drain faster and faster even if u are not using it when the battery gets older
when power saver auto cut off, the balance power in ur battery will drain off faster than new battery
ie. power saver cut off from a new battery, balance power in the battery can last u 48 hrs before it died off
as time goes by, battery gets older and degrade, the balance power in ur battery cannot last u 48 hrs anymore
it will get lesser and lesser
same theory for handphone battery
1-2 yrs old battery will drain faster even if u off the phone