It could be one of any different things why it is not charging..
1. is the battery deformed? you may have over-charged the battery and now it won't charge. How to check: take off the battery back and the battery, feel the battery to see if you feel a bulge.
you can also try spinning the flat side of the battery on a flat smooth surface. if it spins fast it may be time to get a new battery. https://www.youtube.com/watch?v=Y9xQa60eRW4
2. is there lint or some pants pocket debris or dirt inside the charging port on the bottom of the phone? use something non metal that won't break inside, it needs to be thin enough to move around and poke around the bottom, not interfering with the chip that sticks out.
before you do that.. turn off the phone and take out the battery just in case. you don't want to short the charging port, so why risk it.
you can use a thin side wooden tooth pick (not the thick rounded ones, they won't fit), or you can use an unused plastic brush tooth pick that's available at most stores like Walgreens, CVS, Safeway, etc..
3. If nothing comes out, try using a different wall charger adapter that works for your Samsung device. Many cell phones use a 3volt charger that won't work with Samsung smartphones because non-Note Galaxy phones need a 5volt charger. Your Note 4 phone needs a more powerful charging adapter that can draw even more energy to the device. The others will just trickle charge it or may not work at all. Also, the cord itself. You can't just use any micro USB charging cable. You need to use one that can push enough electricity to your device. So it has to be a Samsung smartphone compatible one. If you have ruled this out..
4. Is the wall outlet bad? Try a different wall outlet. Example: at the airport we tried all the wall outlets in the same area, none of those charged the device. We thought it could be the charging cable or the adapter that was dead. Then we went to another area in the airport and tried again. This time we were charging the phone fine. Cable and charging adapter were apparently working great.
5. If the battery is good, but it is a non original manufacturer's battery, does it still have all parts of the battery intact? On many non-OEM batteries there is a plastic foot glued to it so that the battery fits inside the compartment snugly. If this has fallen off and you have a gap in between the battery and battery compartment, whereas the battery can shift inside.. if so, the phone can't charge the battery correctly because the battery is not set tightly inside the phone. If this is the case, slide a folded piece of paper or something in between the bottom of the battery and the battery compartment to make it a tighter fit. Then try charging it.
6. If that's not it.. what happens when you try jiggling the charging cable connected to the phone.. try angling the cable head to the left or right.. does it only charge when in a specific position? it could be the charging cable or the charging port that needs fixing..
7. If that was not the case, and everything you've tried doesn't work, it could just be the charging port on the phone is bad. Bring it to your local cellular repair shop. It should cost around $35 to $50 to fix.