Jk Rs485 Bms10 Modbus Register 4788: Bms10 total charging cycle capacity

Technical Definition

The register bms10 total charging cycle capacity at address 4788 is used to monitor bms10 total charging cycle capacity on the Jk Rs485 Bms10.

• Protocol: Modbus RTU
• Data Type: U DWORD
• 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 bms10 total charging cycle capacity (Address: 4788)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=4788, 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 total charging cycle capacity"
  address: 4788
  value_type: U_DWORD
  unit_of_measurement: "Ah"

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: Accumulated capacity that has passed through the battery over its lifetime. Units are typically Ampere-hours (Ah).

Troubleshooting: A value of 0 indicates no capacity has passed. If the battery has cycled, check BMS logging and potential overflow or reset issues.