
Modbus TCP
Siemens Junelight Smart Battery (grid)
Siemens
Overview
The Siemens Junelight Smart Battery is a modular residential lithium-ion storage system designed to pair with rooftop PV installations. This Modbus TCP template reads the grid-side power register, capturing the real-time power flow between the battery system and the public grid. Positive values indicate import; negative values indicate export. With the ModbusCloud Gateway connected to the same network as the Junelight, you can log grid power continuously, build historical trend charts, and trigger alerts, giving installers and building owners a clear picture of household energy autonomy.
Use cases
- Monitor real-time grid power flow to verify the Junelight Smart Battery is charging and discharging as expected.
- Track grid import and export patterns over weeks to identify periods of excessive grid dependency.
- Alert on sustained grid import during daylight hours, indicating possible battery or PV underperformance.
- Compare logged grid power data before and after battery capacity expansions to confirm expected improvement.








