My iPhone battery seems to be very good when I am in a wifi environment. Over an 8 hour period it will drop from 100% to may 90%. Both my home and work environment are wifi, so all is good. My issue is if I use blue tooth headphones, the battery starts dropping and the thing that is disturbing is that EVEN when I turn the headphones OFF AND kill the MUSIC app, it continues to drop. It is as if once you use bluetooth for music the bluetooth radio keeps transmitting! Comments please?