My audiologist has implied that putting the Smartlink into bluetooth mode can be a huge drain on the smartlink battery. I already know I can get about 10 hours from my smartlink battery, without recharging if the smartlink is not in bluetooth mode at all. Although I don't get a lot of calls on my cell phone I do hear on my cell phone better when calls are coming through the smartlink, especially since I now can here the calls in both ears. So if I leave bluetooth connected on the smartlink all the time I'm just wondering how much faster the battery on the smartlink will drain.