Jk Rs485 Bms10 Modbus Register 4774: Bms10 state of charge

Technical Definition

The register bms10 state of charge at address 4774 is used to monitor bms10 state of charge on the Jk Rs485 Bms10.

• Protocol: Modbus RTU
• Data Type: U WORD
• Unit: %
• 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 bms10 state of charge (Address: 4774)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=4774, 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: "bms10 state of charge"
  address: 4774
  value_type: U_WORD
  unit_of_measurement: "%"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[Jk Rs485 Bms10]

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

💡 Engineer's Insight

Analysis: Indicates the current charge level of the battery pack as a percentage (0-100%).

Troubleshooting: A value of 0% may indicate a fully discharged battery, a sensor issue, or communication error. Verify battery state and connectivity.