I just got a replacement RTC battery from framework after my laptop stopped booting. My first battery lasted about two years. Is it fair to assume this new battery will last about as long?
Mostly depends upon how you use the laptop i.e. how long to you have it on charge and therefore how discharged the ML 1220 gets.
It can only cope with a few dozen deep discharges. My laptop is 26 months old but is powered on and hence keeping the ML 1220 charged 99% of the time. So it may last a few more years in this case.