
Modbus RTU
Sunway wattsonic (battery)
Sunway
Overview
The Sunway wattsonic is a hybrid PV inverter with integrated battery storage, sold in residential and light-commercial installations across Europe. This ModbusCloud template targets the battery subsystem over Modbus RTU and reads battery power flow and state of charge from holding registers 40258 and 43000. It also exposes the on-grid minimum SOC setpoint at register 52503, letting your portal enforce a discharge floor without opening the inverter app. Together these three registers give installers a compact, actionable view of battery behaviour in any wattsonic-equipped site.
Use cases
- Monitor battery charge and discharge power in real time to verify the system follows its configured energy strategy.
- Track state of charge over days and weeks to detect gradual capacity loss across the battery modules.
- Alert on SOC dropping below a threshold during peak-demand evenings to catch unexpected overnight discharge.
- Write the minimum SOC setpoint remotely to reserve battery capacity before a forecast grid outage.




