In the case of the battery not charged enough, the power may not turn on. Charge the cradle by connecting it to the PC using the supplied USB cable Charge the earbuds using the charged charging cradle before use *Charging time Cradle : approximately 1hour *White LED of the cradle blinks during charging and it stays on when the battery is fully charged. Earbuds: approximately 1hour *White LED on earbuds stays on during charging and it turns off when the battery is fully charged. *Number of available CR5 charges using charging cradle (500 mAh): 3~4 times (with fully charged charging cradle) *Music-Playing Time: Single Mode : About 7.5 hours / Dual Mode : About 5 hours