Question 1.

Why the original attached ESC can't operation normally ?

 

Ans :
 

The original attached ESC for H550 helicopter that hasn't with  "BEC function" on it, that is just for controlling the motor speeds. Users need to add an external BEC to provide the current for the electronic parts (servos, gyro, and receiver), and also an additional battery is necessary for this external BEC (the original attached external BEC, we suggest to use a two-cell 7.4V Li-po battery on it).