Modular and scalable storage up to 128 kWh

Fronius Reserva Pro features a modular high-voltage architecture. Each tower consists of 3.98 kWh modules with lithium iron phosphate (LFP) cells, configurable with three to eight units for usable capacities ranging from 11.9 to 31.9 kWh.

The possibility of connecting up to four towers in parallel allows the system to reach a total capacity of 128 kWh, making it particularly suitable for commercial and industrial systems, agri-solar applications, farms and apartment buildings with high or increasing energy consumption.

The high-voltage DC architecture eliminates the need for intermediate DC-DC converters, helping to reduce energy losses and increase overall system efficiency. When combined with the Fronius Verto Plus inverter, the maximum charging and discharging power can reach 28.3 kW.

Operational continuity and Black Start function

One of the most interesting features of Fronius Reserva Pro is the possibility of integrating advanced energy backup functions.

When combined with Fronius backup systems, the battery can continue supplying priority loads during grid outages, ensuring greater operational security for businesses and production facilities.

The Black Start function also allows the inverter to restart autonomously using the residual energy stored in the battery, without requiring an external power supply, enabling the system to resume operation within seconds.

LFP cells and multi-level safety

Lithium iron phosphate (LFP) cells provide greater thermal and chemical stability than NMC chemistries, reducing the risk of thermal runaway. The multi-level safety system integrated into the BMS (Battery Management System) monitors overvoltage and undervoltage, overcurrent, excessive temperatures and cell hardware faults in real time.

The IP65 protection rating allows installation both indoors and in sheltered outdoor areas, with an operating temperature range from –20°C to +50°C.

European production for a more resilient supply chain

Another distinctive feature of Fronius Reserva Pro is the European production of its cells and battery modules.

European origin represents an important advantage for projects applying for incentives or funding schemes that reward Made in EU components. It also ensures greater supply chain transparency and improved resilience.

Smart energy management with Multi Flow Technology

The system benefits from proprietary Fronius Multi Flow Technology, integrated into compatible hybrid inverters.

This solution simultaneously manages energy flows from the photovoltaic system, battery and electricity grid, optimising energy distribution in real time according to the user’s requirements.

Available functions include advanced energy management strategies such as peak shaving, maximisation of self-consumption and scheduled battery charging during periods when electricity prices are lower.

Monitoring and management via Fronius Solar.web

The entire system can be monitored through the Fronius Solar.web platform, available both via web browser and mobile app.

Users can view production and consumption data in real time, analyse battery performance, receive system notifications and manage firmware updates remotely using OTA (Over-the-Air) technology.

Communication takes place via the Modbus RS485 protocol, while the DC-side connection uses Stäubli MC4-Evo stor connectors. The system supports up to four towers connected in parallel and offers an estimated service life of 15 years at 25°C, with a self-discharge rate of less than 1% per month.

Warranty and expansion options

Fronius Reserva Pro is covered by a 10-year warranty, with the battery retaining 80% of its state of health (SOH).

Commissioning can be carried out via the Fronius Solar.start app or directly through the inverter’s web interface.

To ensure maximum consistency in system performance, Fronius recommends completing any capacity expansion within the first two years following installation. Although expansion remains technically possible at a later date, new modules will operate according to the lowest SOH level within the system.

Which applications is Fronius Reserva Pro suitable for?

Thanks to its high scalability and advanced energy management capabilities, Fronius Reserva Pro is particularly suitable for:

• commercial and industrial (C&I) photovoltaic systems;
• farms and agri-solar projects;
• renewable energy communities and apartment buildings;
• production facilities requiring operational continuity;
• systems designed to maximise self-consumption and reduce dependence on the electricity grid.

With a capacity expandable up to 128 kWh, LFP technology, backup functions and European production, Fronius Reserva Pro is positioned as one of the most comprehensive battery storage solutions for the professional photovoltaic market.