After more than year using the Samsung Galaxy Note 4, I have notice that the battery life seems to be deteriorating. The phone shut down at around 20% of battery level. I was thinking of buying a new battery but I remember I read somewhere on the internet that the battery can be recalibrated to restore the correct reading. That would be the first thing I should do before I decided to get a new battery.
From my online research, there seems to be a built-in function in the phone that does the recalibration but there is no official documentation that stated it. I suspect it is possibly built for Samsung production factories to use it whenever they put in a new battery and it is not meant for public usage.
After I ran the recalibration, the battery life seems to improve and the readings are more accurate as in there were no sudden drops of battery life level percentage which I experienced many times and cause the phone to shut down immediately at 20% level.
Below are the steps on how to start the calibration.