A Victron SmartSolar charge controller. An MPPT controller adjusts to the panels so more of their power reaches the battery. You can check it from your phone over Bluetooth. In Victron’s naming, 75/15 means up to 75 V of panel voltage and 15 A of charge current.
Used in our systems: System 1: RV 200W and System 6: Fridge and internet backup.
