I own a samsung S6 and of late the charge has been going quite insane. I will charge it while it's off, but it will take a while during the 90's charging range (say 95%) to get to 100%. But i will leave it for an hour or so to charge a bit longer, but when i turn it on it says 92%. Then it will take forever once again while not being used to reach 100 and i'm really baffled. Any help will be very appreciated and thank you.