Fronius Battery Review: An Independent Assessment by Solar Choice

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Note: Solar Choice is not affiliated with Fronius or any other battery manufacturer. Our reviews are independently written using technical documentation and industry analysis.

At a Glance: Fronius Batteries score 3.6 out of 5

Scoring is based on our solar battery scorecard, which is consistently applied to each brand and battery available on the Australian market. This scoring reflects Fronius’ upcoming Fronius Reserva battery system.

$$$ Price: Pricing for Fronius’ Reserva battery remains to be seen when the battery launches in October 2025, however we expect it to be a premium priced solution.

  • Company Backing and Trustworthiness (5 out of 5): Fronius has had a strong presence in Australia since 2010, with a local office in Melbourne and an extensive installer network. The brand is globally respected, and its reputation in the solar inverter space contributes to a perfect trust score.
  • Warranty Offer (2.5 out of 5): Fronius batteries offer a throughput warranty of 3.1MWh per usable kWh, a 10-year product warranty, and a minimum capacity guarantee of 70% at the end of the warranty period. While reliable, this offering is not class-leading compared to some alternatives.
  • Customer Reviews (5 out of 5): Fronius batteries have received outstanding early feedback, with a perfect score of 5.00 from 2 verified reviews on Solar Choice’s independent platform. This earns the maximum score in our customer satisfaction category.
  • Functionality (2 out of 5): Fronius batteries are IP65 rated, modular, and include AFCI technology for added safety. However, they lack AC coupling, built-in fire suppression, and module-level balancing, meaning new batteries added to a system may be affected by older ones. These limitations impact long-term flexibility.

Overview of Fronius – Company History

Fronius is an Austrian technology company with over 75 years of history in power electronics and renewable energy systems. Globally, the company is best known for its high-performance solar inverters and strong engineering standards, and it remains a family-owned business with a reputation for durability and customer support. In Australia, Fronius has been active since the early 2000s and has built a strong local presence, including a technical support hub and a wide network of accredited installers, particularly for their inverter range which is often recommended by Australian solar professionals.

In 2016, Fronius first launched a home battery solution which didn’t make much of a mark and it was ultimately discontinued. The new Fronius Reserva battery—expected to launch in October 2025—marks a fresh start for the company in the storage sector, featuring a redesigned system focused on performance, integration, and long-term reliability for residential users.

Fronius Battery Range and Options

Fronius Reserva

The Fronius Reserva is a high-voltage, DC-coupled modular battery designed exclusively for use with Fronius’s hybrid inverters—specifically the Primo GEN24 Plus and Symo GEN24 Plus series which first launched in Australian in around 2021.

Fronius Reserva Battery with Fronius Gen24 hybrid inverter

Each battery tower consists of 2 to 5 stackable modules, each rated at 3.15 kWh of usable capacity. That means each tower can range between 6.31 kWh and 15.79 kWh, and 4 towers can be combined together for larger requirements reaching a maximum capacity of 63 kWh.

Key features include:

  • LiFePO₄ battery chemistry with high thermal stability
  • IP65 rating, allowing for outdoor installation in sheltered areas
  • Backup power support with black-start capability when paired with Fronius inverters and accessories
  • Full integration with the Fronius Solar.web monitoring platform

The battery is intended for use in new installations or with existing Fronius GEN24 inverters, and is not suitable to retrofit with other brands of solar inverters.

How Much Does a Fronius Battery Cost?

The Fronius Reserva is expected to launch in October 2025. At the time of writing, there is no published pricing, but based on Fronius’s historical positioning, it is expected to be a premium-priced product.

For reference, comparable premium batteries (e.g., Enphase, Tesla Powerwall, Sonnen) typically cost $1,200–$1,500 per usable kWh installed prior to any rebates being applied. Pricing for Fronius Reserva will also depend on system size, number of modules, and specific installation requirements.

Federal & State Battery Rebate Applies to Fronius Batteries

As of 1st of July 2025, there is a federal battery rebate which can reduce the cost of installing a battery by around 30%. You can check out our federal battery rebate calculator to see how this would apply to similar batteries to the Fronius Reserva and we will add their pricing in once release in October.

This rebate can be paired with the state battery rebate in WA and the NSW VPP Rebate.


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Fronius’s Warranty Offer For Australian Customers

Fronius offers a 10-year product and performance warranty on the Reserva battery. The performance warranty guarantees:

  • Minimum retained capacity: 70% of usable energy after 10 years (on par with mid-range solutions)
  • Minimum throughput per usable kWh: 3.1 MWh/kWh (on par with mid-range solutions)

Customers perhaps would have hoped for Fronius to go beyond the average for their warranty and back the longevity of their product given their reputation for premium solutions. The same Reserva batteries are guaranteed to 80% in Europe and other countries and it is unclear why they have lowered that for the Australian and New Zealand market.

Conditions:

  • Must be installed and commissioned by a certified Fronius installer
  • System must be registered and monitored via Fronius Solar.web
  • Battery must be operated within environmental and usage limits (e.g., temperature and charge cycles)

To make any warranty claims or seek technical support, Fronius are one of the brands with the strongest local Australian presence to help you out.

See Fronius’ full warranty T&Cs here.

Fronius Battery Technical Specifications Table

FeatureFronius Reserva 6.3Fronius Reserva 15.8
Usable Capacity6.31 kWh15.79 kWh
Battery Modules25
ChemistryLithium Iron PhosphateLithium Iron Phosphate
Round-Trip Efficiency>90% (DC-coupled)>90% (DC-coupled)
Max Continuous Output~5–10 kW (inverter-limited)~5–10 kW (inverter-limited)
IP RatingIP65IP65
Dimensions (H × W × D)860 × 780 × 176 mm1610 × 780 × 176 mm
Weight86.6 kg187 kg

Pros and Cons of Fronius Batteries

ProsCons
Seamless integration with Fronius hybrid inverters and their app and monitoringOnly compatible with Fronius GEN24 series – older Fronius inverters (installed from around 2021 and before) would need to be upgraded
Fronius are a well-established global brand with a very proven track record in high quality productsWarranty terms are mediocre and offers less than customers would expect from a premium offer
Modular and stackable solution in 3.15kWh increments offering customers flexibility in system size and designNew product with no long-term performance track record in-market

Conclusion: Our Verdict on Fronius Batteries

The Fronius Reserva battery is a well-engineered, high-end storage solution best suited to homeowners planning to install a complete Fronius solar system. Its modular design, tight inverter integration, and black-start backup support offer a robust and user-friendly experience.

However, it will only appeal to a niche audience due to its expected premium cost and Fronius-only inverter compatibility. While its performance in the field remains to be seen, the company’s strong Australian track record suggests it will be a dependable choice for those seeking a reliable, all in one solar and battery package.

Read more product reviews from Solar Choice


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Jeff Sykes

Reviews from Australians who have installed Fronius Batteries

Rated 5.00 from 2 reviews
5 star
2
4 star
0
3 star
0
2 star
0
1 star
0

Showing 2 of 2 Reviews

2nd November 2024
Glenn
-
10-15kW system
5.00

So far so good. Again, I left it up to the Solar installer to recommend, but I am very happy so far

3rd January 2025
Harsh
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10kW system

Review left 5 years after system installed

5.00

Batteries are completely working fine

Showing 2 of 2 Reviews