Deye12 Modbus Register 591: Sun12k-Battery output current
Technical documentation for Modbus register 591 on Deye12. Data type: S WORD. Includes Python and YAML configuration examples.
January 16, 2026
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Technical Definition
The register sun12k-Battery output current at address 591 is used to monitor sun12k-battery output current on the Deye12.
- Protocol: Modbus RTU
- Data Type: S WORD
- Unit: A
- 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 sun12k-Battery output current (Address: 591)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=591, 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: "sun12k-Battery output current"
address: 591
value_type: S_WORD
unit_of_measurement: "A"
Connection Diagram
Here is the standard RS485 wiring for this configuration:
graph TD
PLC[Host Controller / Home Assistant]
Device[Deye12]
PLC -- "A+ (D+)" --> Device
PLC -- "B- (D-)" --> Device
PLC -- GND --> Device
💡 Engineer's Insight
Analysis: Instantaneous current flowing from the battery in Amperes (A). Positive for discharge, negative for charge.
Troubleshooting: Zero if battery is idle. Error if current exceeds limits or is unexpected.