RE: E-sky honey bee king 2
Never charge rechargeable AA batteries through the transmitter. Any transmitter, no matter what the brand is.
The Esky transmitter is not designed so to use the charging port. It is there for unknown reason...
If you want to charge rechargeable AA batteries then just take a separate charger.
One more thing. The Esky transmitter works better with alkaline AA batteries. If it is the 2.4Ghz version then the batteries last for a long time.