
Modbus TCP
Marstek Venus E Gen 3.0 (battery)
Marstek
Overview
The Marstek Venus E Gen 3.0 is an AC-coupled residential battery storage system with a 5.12 kWh LiFePO4 pack, designed to maximise solar self-consumption alongside an existing grid-tied inverter. This ModbusCloud template reads AC power flow (charge and discharge direction) and battery state of charge via Modbus TCP, and exposes four write registers that control operating mode, force charge/discharge direction, and charge power setpoint. Integrators can monitor live energy balance and push remote mode changes through the ModbusCloud Gateway without relying on the Marstek app.
Use cases
- Monitor battery state of charge in real time to verify the system charges fully during peak solar hours.
- Track the power register to confirm the battery is discharging into the home during evening demand peaks.
- Alert on sustained zero power readings after a forced charge command to detect communication or RS485 control-mode failures.
- Compare cumulative energy throughput over time to estimate battery cycle consumption across multiple sites.



