Generally, it takes 2-3 hours to charge a Bluetooth headset, and a fully charged Bluetooth will have a blue indicator on.
The Bluetooth headset battery is not fully charged when it leaves the factory. To fully activate the battery, charge the first three times for 6-8 hours. After each charge 2-3 hours can be. When charging, it is generally a red light, the headset is full of blue lights or green lights, and some of the lights are long after being fully charged.