I made a holder for my motorcycle with a car kit. I tried it out using only battery power until I can get a plug in wired. I drove for about 45 minutes with it playing with no problem, but then it shut off. After that it would shut off after playing only a few minutes at a time. The battery was only half gone, and if I took it out of the holder and put it in my pocket, it would play with no problems. Do you think that the vibration from the motorcycle was causing this? Is there an issue with the dock that makes it shut off with a battery half charged? I'd keep it in my pocket, but I can't get the satellites that way, only recorded stuff. Any suggestions?