My Ps4 controller keeps getting disconnected and won't charge

I've had my Ps4 for a good 9 months and have never had any problems with the controller. But recently, it's been getting disconnected every time I turn it on, I don't even have time to press any buttons. The first time it happened I left it on the charger in rest mode for a few minutes, and then it was fine. But it happened again, so I left it on the charger over night. I woke up and got a good 30 seconds out of the controller, but after that I couldn't do anything else. There appears to be nothing wrong with the charger or controller (Physically at least)