I'm looking at Quatro 12/5000/120. to "charge" the batteries only. im looking at this device because of its high amp charge rate. I'm assuming the 200 amp charge rate is if I am inputting 120 volt 50 amp. My problem is the input to this device will only be 120 volt 30 amps. At 120/30 input what would my charge rate be? would it be cut down to 120 amps?