Deye Seplosv3 Modbus Register 4099: Bms name total capacity

Technical Definition

The register bms name total capacity at address 4099 is used to monitor bms name total capacity on the Deye Seplosv3.

• 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 bms_name total capacity (Address: 4099)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=4099, 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: "bms_name total capacity"
  address: 4099
  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[Deye Seplosv3]

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

💡 Engineer's Insight

Analysis: Total battery pack capacity in Ah. Represents the maximum charge the battery can hold when fully charged.

Troubleshooting: Inaccurate value may point to calibration issues or BMS fault. Compare with manufacturer specs and observe capacity changes over time.