Device Growatt Spf Modbus Register 17: Name inverter name battery voltage

Technical Definition

The register name inverter name battery voltage at address 17 is used to monitor name inverter name battery voltage on the Device Growatt Spf.

• Protocol: Modbus RTU
• Data Type: U WORD
• Unit: V
• Access: Read Only

How to Read (Python pymodbus)

Use this code snippet to read this specific value via RS485:

from pymodbus.client.sync import ModbusSerialClient

client = ModbusSerialClient(method='rtu', port='/dev/ttyUSB0', baudrate=9600)
client.connect()

# Read name_inverter_name_battery_voltage (Address: 17)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=17, count=2, unit=1)

if not result.isError():
    print(f"Raw Value: {result.registers}")
else:
    print("Error reading register")

client.close()

Integration (Home Assistant)

Paste this into your configuration.yaml:

- platform: modbus_controller
  name: "name_inverter_name_battery_voltage"
  address: 17
  value_type: U_WORD
  unit_of_measurement: "V"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[Device Growatt Spf]

    PLC -- "A+ (D+)" --> Device
    PLC -- "B- (D-)" --> Device
    PLC -- GND --> Device

💡 Engineer's Insight

Analysis: Battery voltage (V). Actual voltage of the connected battery bank.

Troubleshooting: Zero if battery disconnected or faulty. Low reading indicates discharged battery or connection issue.