{
  "spec_version": 1,
  "slug": "marstek-jupiter-c-plus",
  "manufacturer": "Marstek",
  "model": "Jupiter C Plus battery storage",
  "category": "Home battery",
  "supplier_url": "https://marstekenergy.com/",
  "default_configuration": {
    "protocol": "modbus_tcp",
    "port": 502,
    "unit_id": 1,
    "addressing": "zero_based",
    "byte_order": "BigEndian",
    "word_order": "HighFirst",
    "native_interface": "rs485",
    "serial": {
      "parity": "None",
      "baud_rate": 115200,
      "data_bits": 8,
      "stop_bits": 1
    }
  },
  "coils": [],
  "discrete_inputs": [],
  "input_registers": [],
  "holding_registers": [
    {
      "address": 3,
      "count": 1,
      "name": "PV1 power",
      "data_type": "UInt16",
      "units": "W",
      "scale_factor": 1,
      "offset": 0,
      "access": "R"
    },
    {
      "address": 6,
      "count": 1,
      "name": "PV2 power",
      "data_type": "UInt16",
      "units": "W",
      "scale_factor": 1,
      "offset": 0,
      "access": "R"
    },
    {
      "address": 9,
      "count": 1,
      "name": "PV3 power",
      "data_type": "UInt16",
      "units": "W",
      "scale_factor": 1,
      "offset": 0,
      "access": "R"
    },
    {
      "address": 12,
      "count": 1,
      "name": "PV4 power",
      "data_type": "UInt16",
      "units": "W",
      "scale_factor": 1,
      "offset": 0,
      "access": "R"
    },
    {
      "address": 13,
      "count": 1,
      "name": "AC output power",
      "data_type": "UInt16",
      "units": "W",
      "scale_factor": 1,
      "offset": 0,
      "access": "R"
    },
    {
      "address": 16,
      "count": 1,
      "name": "Battery state of charge",
      "data_type": "UInt16",
      "units": "%",
      "scale_factor": 1,
      "offset": 0,
      "access": "R"
    }
  ],
  "combined_registers": [],
  "notes": "Marstek Jupiter C Plus is a balcony/home storage unit with four PV inputs; the base unit is 2.56 kWh and each extension adds 2.56 kWh (the cited template's capacity help text). Source: the evcc meter template https://raw.githubusercontent.com/evcc-io/evcc/master/templates/definition/meter/marstek-jupiterc-plus.yaml, used as a secondary source; no Marstek register document was retrieved. RS-485 device: the template states 115200 baud and 8N1 framing and leaves evcc's default unit ID 1 in place, so reach it through a Modbus RTU-to-TCP gateway with those settings. All rows are holding registers. Battery power is not a register of its own: the template computes it as AC output power (13) minus the sum of the four PV powers (3, 6, 9, 12), so the app can build the same calculated row from this map. The template publishes nothing else - no grid meter, no temperatures, no battery voltage/current - and that is why this seed is short rather than padded with guessed addresses. Marstek's Venus A/D and Venus E Gen 3 lines have their own seeds and a different map."
}