If I plug my phone into my car's USB port it won't charge. The car (Infiniti) looks at it for a minute and then decides it doesn't know what it is and nothing happens. I have used it in various rental cars on my travels, and some work and some don't. I remember it worked in a Ford Fusion, but not in a Honda Accord. Is there some kind of electronic compatiibilty issue? Oh, I have an AT&T 1520.