600 watts is about 60 amps if you are drawing off the house batteries 5 amps if on 120 volts. but the Stereo draws more than that (Likely 2x) at full output
Another thing. You are not likely ever to hit Full Output with that device and thus ower consumption is reduced even farther
The only way to be sure is to plug in a Kill-a-watt meter plug the stereo into that and let it run for an hour or two.. Then by pushing buttons you get the total KWH used, total KW's used, and finally the Up Time of the meter.
Do the math and you have averages. Then we can do the math or you can do it, either way.
