The battery on a PS4 controller is rated for around 8 hours of gameplay. If you start to notice the controller dying long before that 8-hour is up, the battery could be on its way out ...

The new Playstation 4 Dualshock controllers are super high-tech ... it will still be at approximately 66% battery capacity after the same amount of time. Another user on the forums quickly ...

As long as the PS4 is switched on (it can be in Rest Mode), the controller will commence charging. A complete charge takes about two hours. You should be sure to let the battery run out ...