Hi All, I just had a new electric thruster installed. My old on needed the motor rebuilt & it was just more cost effective to replace entire unit. The old unit would not rev very high and would quickly drop the volt meter below 10 volts. The new unit really is powerful and moves the bow strongly. Problem is this unit after 3-4 short bursts of power drops the voltage to 10volt & runs very slow, just like the old one. I had the wiring & batteries checked & all checked out well. I have 2 group 31s on 2 banks. I am going to replace the alternator, as it is getting weak. My question is should not 2 new group 31 batteries be able to power the unit with out the help of the alternator? Nominal thruster amp draw is 350 cca and my batteries far exceed this.