Gamesir x4 Aileron Charging?

Hi, I want to know if my Gamesir x4 Alieron have been 100% charged ? Is there any indication to know? Because whenever the white light became solid, i would assume it had been charged completely but when using for 6 hours , it would be orange light and even red, the Gamersir x4 alieron was advertise to last for 20 hours but I find it hard to believe. Therefore would appreciate if anyone could tell me how to know if its fully charged.