Note 4 battery only going to 80%

[gietek]

I had this problem a few times. The only solution was clearing cache partition via recovery mode.

 

[a-ghazal]

I have the same problem, and been solved by reverting back an older version of the firmware.
The version which has the charging issue problem is: 6.0.1, and been replaced by: 5.1.1.
I downloaded this firmware from https://www.sammobile.com and used Oden to flash the Note4 operating system.
The mobile keeps rebooting after the downgrade, but when reset the mobile to factory all problems been solved.

Samsung! I wonder how a new software update would cause major defects in your mobiles.