So I'm having some trouble with a Phantom 4 I recently purchased used off of LetGo (an app like Craigslist), and we're having some trouble with the charging of the controller. Ill plug it in, and it will be one blinking white light when I have it charging and then it will go to solid red. After leaving it for a couple hours, I go to turn it on and I have the same white blinking light but shortly after it starts beeping and then says that it is at 5% charge. Basically the controller works fine if its plugged in to something, but it doesn't seem to be able to hold a charge. Any input is much appreciated!