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Esphome Shoto Smartli Modbus Register 271: Cell Count

Technical documentation for Modbus register 271 on Esphome Shoto Smartli. Data type: U WORD. Includes Python and YAML configuration examples.

January 16, 2026 3 read

Technical Definition

The register Cell Count at address 271 is used to monitor cell count on the Esphome Shoto Smartli.

  • 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 Cell Count (Address: 271)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=271, 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: "Cell Count"
  address: 271
  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[Esphome Shoto Smartli]

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


💡 Engineer's Insight

Analysis: Number of battery cells detected and configured in the system. Dictates battery pack configuration.

Troubleshooting: 0 might mean no cells are detected, a configuration error, or a problem with the cell sensing mechanism. Verify cell connections and configuration settings.