Atom S3 Lite Rs485 Modbus Register 35011: Min Cell Temperature

Technical Definition

The register Min Cell Temperature at address 35011 is used to monitor min cell Temperature on the Atom S3 Lite Rs485.

• Protocol: Modbus RTU
• Data Type: S WORD
• Unit: °C
• 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 Min Cell Temperature (Address: 35011)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=35011, 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: "Min Cell Temperature"
  address: 35011
  value_type: S_WORD
  unit_of_measurement: "°C"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[Atom S3 Lite Rs485]

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

💡 Engineer's Insight

Analysis: Minimum recorded cell Temperature in degrees Celsius. Indicates the lowest Temperature experienced by any battery cell.

Troubleshooting: Exposure to extreme cold, sensor malfunction, or potential issue with cell self-heating.