
Modbus TCP
Marstek Venus A (battery)
Marstek
Overview
The Marstek Venus A is an all-in-one AC-coupled home battery with integrated inverter, designed for balcony and residential solar installations. This Modbus TCP template connects via an RS485-to-Ethernet adapter and reads instantaneous AC power, cumulative energy, and battery state of charge. It also exposes four write registers that control RS485 enable, user work mode, force charge/discharge mode, and charge power setpoint. Using this template in your ModbusCloud portal, you can monitor and remotely control the Venus A without relying on the Marstek cloud app.
Use cases
- Monitor battery state of charge continuously to detect when the Venus A drops below your daily reserve target.
- Track cumulative energy throughput over months to verify expected cycle count against LFP degradation curves.
- Alert on unexpected charge or discharge power readings that may indicate a misconfigured work mode.
- Compare instantaneous AC power against site consumption to verify the anti feed-in mode is holding grid export near zero.





