That's a good point mike, but I let the boat run bc it literally will play for hours. On Tuesday night when the alternator let go, the boat ran the entire time the stereo played probably about 6 hours and it pulled the batteries down and the 70 amps max that that thing could put out was not enough to keep them charged. before, the voltage while running and playing the boat would start out at about 14 Volts, then once played for a while. The voltage would start to come down And hang around 12 so I'd turn the stereo down and let the alternator charge them back up. Now that thing is a monster. It can hold a solid 13.5 volts on my digital voltage gauge and it never fell off last night.