a) Before measuring the battery drain make sure your device is 100% charged
b) Listening the music on higher volume will certainly affect the playtime
Ideal volume level should be 50-70%
c) Long time call and Playing game while using the device will cause more battery consumption
d) Varying BT range will affect the device playtime significantly
e) Bluetooth battery consumption varies with different mobile phone models
f) Online streaming consumes more battery than downloaded files