1. Before measuring the battery draining time make sure your device is 100% charged 

a) Charge the device to full

b) Listening to the music at higher volume will certainly affect the playtime Ideal volume level should be 50-70%"

c) Listening to music at 50-70% is recommended to have better playtime

2. Long time calls and Playing games while using the device will cause more battery consumption

3. Varying BT range will affect the device playtime significantly

4. Bluetooth battery consumption varies with different mobile phone models

5. Online streaming consumes more battery than downloaded files