Fronius - Battery Reviews

About Fronius

Fronius is one of the world's longest established solar brands and the company's inverters are widely regarded as among the best, if not the best, in the world. The company also put its toes in the water in relation to manufacturing energy storage products with the Fronius Solar Battery, which has since been discontinued - but a new battery called the Reserva is on its way.

Australian Office Contact Details

Address: 90-92 Lambeck Drive Tullamarine VIC 3043
Tel.: 03 8340 2900
Email: [email protected]
Australian Website

Company Info

Fronius was founded in 1945 in Pettenbach, Austria, and originally produced battery chargers and welding transformers; which it continues to manufacture today. The company has also been producing solar components since 1992 - well before the PV revolution as we know it began.

The Fronius Solar Battery (Discontinued)

The Fronius Solar Battery was the company's first contribution to the home energy storage arena. It used lithium-iron phosphate storage technology - generally considered the safest of currently commercially available lithium-ion chemistries. 

The base model was 4.5kWh, but could be expanded to as much as 12kWh capacity (9.6kWh usable) using 1.5kWh modules. The power rating was good at 4kW steady for the 12kWh configuration. The battery could be purchased as part of the Fronius Energy Package, which also included the Fronius Symo hybrid inverter and smart meter.

Among some of the disadvantages of the Fronius battery was its rather high price, it could only be installed indoors, it had a comparatively short warranty (even though it had a long expected design life) and it could only be used in three-phase homes.

Also, the smart meter included as part of the Fronius Energy Package didn't compare well against the features and capabilities offered by Solar Analytics.

Fronius stopped offering this battery in 2023.

Fronius Reserva

Launched in March 2025, the Fronius Reserva battery should be available in Australia towards the end of this year. Some product highlights:

• A modular system with capacities of between 6.3 kWh and 15.8 kWh in 3.15 kWh increments.
• Lithium-iron phosphate (LFP/LiFePO4) chemistry.
• Can be used with Symo/Primo GEN24 Plus hybrid inverters.
• Can be installed outside with appropriate protection.
• Can be used with single-phase homes.
• Backup power and black start capable.
• A maximum of four battery towers can be connected in parallel, for a maximum storage capacity of 63 kWh.
• Integrates with Solar.web.

With a depth of 176 mm, the Reserva is quite a slim battery.  

Warranty Information

The Fronius solar battery warranty wasn't much chop given this was a quality product from a quality company - it was just 5 years if the battery purchase was registered with Fronius within 30 days, otherwise only 2 years. It was certainly good incentive to register quick-smart.

The Reserva warranty is 10 years. Fronius guarantees that the Reserva will still deliver at least 80 percent of its usable energy after ten years.

If you're one of the Australians to install a Fronius energy storage system, contribute your opinion by leaving a rating and review here and let others know how it has been performing.