starts the songs automatically on the USB stick and play the loop continues. 500 watts is of course a huge nonsense, because only what goes in to power can also come out again. with a 12V / 2A power supply an external hard disk that is then a maximum of 24 watts. what it looks like with a car battery like someone testing. all grunts when it set too low, which seems to come from the RCA connectors, you should not touch. possibly you could lay their mass to the mass of the power supply and then maybe go quietly also. FM and remote control I have not tested. for the price spike.