Device Seplosbmsv3 Modbus Register 4099: Name bms name battery capacity

Technical Definition

The register name bms name battery capacity at address 4099 is used to monitor name bms name battery capacity on the Device Seplosbmsv3.

• 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 name_bms_name_battery_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: "name_bms_name_battery_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[Device Seplosbmsv3]

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

💡 Engineer's Insight

Analysis: The total rated energy capacity of the battery (in Ampere-hours or Watt-hours). Defines the battery's maximum energy storage.

Troubleshooting: Zero could indicate a BMS configuration error, a faulty BMS, or a data communication problem. Reconfigure BMS or check data link.