Pack Modbus Register 6: Friendly name pack Design Capacity

Technical Definition

The register friendly name pack Design Capacity at address 6 is used to monitor friendly name pack design capacity on the Pack.

• Protocol: Modbus RTU
• Data Type: U WORD
• Unit: Ah
• 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 friendly_name pack Design Capacity (Address: 6)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=6, 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: "friendly_name pack Design Capacity"
  address: 6
  value_type: U_WORD
  unit_of_measurement: "Ah"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[Pack]

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

💡 Engineer's Insight

Analysis: The original or rated maximum energy capacity of the battery pack, in mAh or Wh.

Troubleshooting: Baseline for health assessment. If Full Capacity is lower, it signifies capacity fade.