I know I sound paranoid, and I know the plugs are the same. What concerns me is the voltage coming from that 12v cig lighter. What reduces it to 5v? I know the PC does it, but this thing looks just like any cig plug adapter. Thanks again.
Voltage on a USB connector is 5v no matter who makes the whatever device, it's a standard; to answer your question it's down converted inside the cigarette plug, plug-in adapter. The only real difference in these adapters and also the ones you buy for your home to convert household voltage to DC 5v USB plug, is the amount of amperage they put out, it can vary greatly. Look for output 5v DC @ 1A Max (1000ma).
5v DC @ .5A Max (500ma) would probably work. If the adapter gets really hot, then it usually means it's not supplying enough output and you then should go with a higher ampere model.
I have a Garmin one sitting right here and it says output 5V DC @ 1A MAX it runs ice cold. I also have 2 different ones from Motorola 1) 5V DC 1A MAX, ice cold & the other is 5V DC 850MA a tiny bit warm.
Most adapters also have internal fuses, IF that blows then you definitely overloaded it, rare though especially using brand name adapter like Moto. Help this helps.