Review on AIMS Power CON120AC1224DC AC Converter & Battery 12V or 24V Smart Charger 75 amps UL 458 & CSA Listed by Doug Darling

4 Trojan L16 1500W batteries discharged in 1 hour. The charger took 4.7 hours to charge the battery to a trickle state. A 1200W generator will charge at the full charge management setting, while a 1000W inverter generator will only charge at 75%. between the battery terminal and the positive terminal of the charger when connecting and disconnecting batteries. Sparks around batteries are not good. I have a question: when the charger is off, how much current does the charger draw from the batteries?