Samsung S6 is not fast charging

[Android Central Question]

I am using a Samsung Fast Charger. I'm also using a brand new charging cable. Everything is plugged in correctly. The fast charger setting is turned on under Battery/Advanced Settings. The notification says 'Fast Charging' and in parentheses (approximately 43 minutes until fully charged) no matter what percentage of charge is on the phone. Sometimes the number of minutes varies but it almost always says 43. Also, the phone also seems to be losing its charge more quickly than before. What the heck is going on? And what can I do?

 

[Rukbat]

How low do you allow he battery to discharge before charging it? If you've been allowing it to get much below 40% for a few years (the phone came out over 3 years ago), it's amazing that the battery lasted this long. Charge to 80%, start charging when it gets down to 40%. Lithium batteries are not deep-discharge batteries. (They're light and small, that's why they're used in cellphones.)

 

[chanchan05]

At this point also the battery is over 3 years old. Batteries normally hold out 2 years or so. There's a chance that the battery is shot.