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Esphome Web 51C8D0 Modbus Register 516: Device type-Total charge of the battery

Technical documentation for Modbus register 516 on Esphome Web 51C8D0. Data type: U DWORD R. Includes Python and YAML configuration examples.

January 16, 2026 1 min read

Technical Definition

The register device type-Total charge of the battery at address 516 is used to monitor device type-total charge of the battery on the Esphome Web 51C8D0.

  • Protocol: Modbus RTU
  • Data Type: U DWORD R
  • Unit: kWh
  • 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 device_type-Total charge of the battery (Address: 516)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=516, 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: "device_type-Total charge of the battery"
  address: 516
  value_type: U_DWORD_R
  unit_of_measurement: "kWh"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[Esphome Web 51C8D0]

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


💡 Engineer's Insight

Analysis: Represents the cumulative energy delivered to the battery for charging, typically in Wh or kWh.

Troubleshooting: Zero indicates no charging has occurred since reset or initialization.