Fronius Reserva Pro BMS 4,240,391 with base is the control, connection and mechanical foundation for one modular Reserva Pro high-voltage battery tower. It calculates state of charge, monitors the modules, handles safety functions and communicates with the inverter. It contains no battery cells and stores no energy. A working tower requires three to eight separately purchased matching 3.98 kWh Reserva Pro modules, a compatible Fronius hybrid inverter, project protection, cabling and professional commissioning.

Exact sold assembly

• Sold item: 1 × Fronius Reserva Pro BMS with base, article 4,240,391
• Compatible tower size: 3–8 matching Reserva Pro modules
• System usable energy after adding modules: 11.9–31.9 kWh
• BMS: 225 × 570 × 440 mm, 10 kg
• Base: 70 × 579 × 449 mm, 8 kg
• Combined BMS/base dimensions before modules: approximately 295 × 579 × 449 mm, 18 kg
• BMS-to-inverter communication: CAN / Modbus (RS485)
• BMS-to-module communication: ISO-SPI
• Complete correctly assembled system: IP65, −20 to +50 °C, indoor or protected outdoor installation

Battery management and compatibility

The BMS calculates state of charge, monitors overvoltage, undervoltage, overcurrent, temperature and cell or hardware faults, supports dark start, exchanges operating data over RS485 and receives battery firmware updates through the inverter interface. Automatic state-of-charge balancing is available for correctly replaced or added modules. The current Fronius compatibility table covers selected Primo GEN24 Plus, Symo GEN24 Plus and Verto Plus models; Fronius Symo Hybrid is excluded. Up to four equal-capacity towers may be operated in parallel, subject to current design rules.

Official package contents

The documented package contains one BMS, one L-shaped mounting bracket, two fastening clips, one cable lug, four Stäubli MC4 EVO STO 6 mm² (+/−) connectors, four 10 mm² (+/−) connectors, three RJ45 screw connections, one M4×10 TX20 screw, two M5×10 TX20 screws, one quick-start guide and one base plate. Matching battery modules are not included.

Project limits and installation

Battery modules, inverter, backup switching, meter, external protection, project cables, wall and floor preparation, installation and commissioning are separate. This is high-voltage equipment for qualified installation. The supporting structure, anti-tip fixing, clearances, cable routing, inverter firmware and exact permitted configuration must be checked against the current Fronius documentation before assembly. Fronius states a ten-year system warranty with 80% state of health; the applicable current terms and exact sealed article are confirmed before dispatch.

and . Pair it with the Fronius Reserva Pro 3.98 kWh module, browse battery accessories or the Fronius energy-storage range.