A sufficiently charged Controller battery is just as important to a successful flight as the main drone battery. A fully charged Controller battery lasts about six hours, but it is important to check the battery level before each flight to avoid having your flying time cut short.
To charge the Controller battery:
Insert the barrel jack plug of the Controller charger into the barrel jack receptacle on the side of the Controller. Then plug the opposite end's power adapter into an AC wall socket.
The Controller then displays a charging confirmation screen with the current charge.
While plugged in, the Controller keeps you updated on its charging status.
To check the current battery level, simply press the power button while the Controller is off.