I figured out why my battery was draining fast through trial and error. Letting the battery drain to 0% and recharging did not help me, which was one posted solution that I tried. My Samsung Note 2014 Edition tablet battery had been giving me 7 hrs. or so of service before it would drain to 0%. Then all of the sudden, like a day later I was only getting 3 hrs. off of a full charge. Here's what the problem was and how I fixed my problem: The problem was that I was initially charging my tablet with the original wall charger and USB to mini USB cord with no issues. In the meantime, I had bought some generic chargers for when I might be in a different room and want to put my tablet on charge. It was when I was using the generic chargers that my tablet began draining fast, even though the generic chargers charged the tablet to 100%. Here's how I fixed the problem? I stopped using the generic chargers and only use the charger and cable that came with my tablet. Then, I had to take the tablet apart as if I was going to change batteries. There are many youtube videos that show you how to change batteries on a tablet. Then I simply manually disconnected the power plug from the battery (I did not have to physically remove the battery), waited about 10-15 seconds and then re-connected the battery in my tablet and then put the table back together. I restarted my tablet, went in to the Settings and opened up the Battery link. There it shows you how long you have used your battery since the last charge and how much time you have left. Immediately it said I have about 7 hours left, when before I could only get 3 hours out of the battery.