The remote controller I use for the Phantom 4 keeps beeping with a red light and says it is low battery even though I know the controller is fully charged. It may have been a firmware update problem but I can't rollback the firmware and I'm not sure what to do. Can anyone help?

Happened to me last night. Plugged in to charger for 10 seconds and problem went away for good.

Please try to charge your RC longer. If it doesn't help, you can try to calibrate your remote by moving the stick. The RC sounds when the control stick is not in the central position. You can check if there is an error message from app and tell us for further analysis. Thanks for your cooperation.