We have many solar battery charger controllers - up to 50A - but they only work on one battery bank. This unit will charge TWO house battery banks or one house bank and your motor start battery as well. Too often the motor start battery is forgotten if you are camped in the one spot for a long time. Will charge 2 completely separate battery banks at the same time Highly efficient PWM (Pulse-width modulation) charging system Electronic protection from over charging short circuit or accidental reverse battery connection Max solar input voltage: 30V (12V system), 55V (24V system) Battery input voltage range: 8-15V (12V system), 8-30V (24V system) Overnight self-consumption: 4mA Recommended solar panel to utilise output of this controller. ZM9059, 8.3A unit. (Note output of this controller is limited by the current output of the solar panel feeding it).