Note: This is a high-quality compatible MPPT + PWM solar charge controller, not a 100% true MPPT. The controller automatically detects 12/24/36/48V battery systems. However, the required photovoltaic panel voltage varies depending on the battery voltage. For a 12V battery, use approximately 18V solar panels; for a 24V battery, use 30-37V solar panels; for a 48V battery, use 60-72V solar panels. Always connect the battery to the controller first, then connect the solar panel. When disconnecting, reverse the order—disconnect the solar panel first, then the battery—to avoid potential damage to the controller. Charging Protection Description: For 12V batteries, boost charging activates when battery voltage exceeds 14.8V, switching to float charge at 13.8V. For 24V batteries, boost charging activates when battery voltage exceeds 29.6V, switching to float charge at 27.6V. For 36V batteries, boost charging activates when battery voltage exceeds 44.4V, switching to float charge at 41.4V. For 48V batteries, boost charging activates when battery voltage exceeds 59.2V, switching to float charge at 55.2V. Important: Always connect the battery to the controller before connecting the solar panel. Ensure the battery voltage is above the minimum detection level (12V battery >10V; 24V battery >20V; 36V battery >30V; 48V battery >40V) to prevent voltage identification errors. Color: Black Material: Plastic Type: 100A Package Contents: 1 x Solar MPPT Controller Note: The package includes only the items listed above. Other accessories are not included. Lighting and monitor differences may cause slight variations in color between the product image and actual item. Measurement error allowance is +/- 1-3 cm.