This article was written by Reefe Eleftheriou, NETCC accredited solar installer and co-founder of the Solar Guide Australia. All views are independent. Solar Guide Australia does not receive commissions from manufacturers.
Fronius has spent years as one of the premium inverter brands in Australia. Back in the solar boom ten years ago, they were the brand that took over from SMA as the go to option for anyone wanting European engineering and long term reliability. For a long time, though, batteries weren’t part of that story. Fronius inverters were mostly paired with BYD batteries, and it wasn’t until relatively recently that Fronius released its first ever battery, the Reserva.
That history matters. Fronius has built its reputation as a European manufacturer producing consistently reliable and safe products built to last, and that reputation carried straight into their first battery. The catch is that the Reserva was designed more for the European market, and its capacity reflected that. For Australian homes generating plenty of solar, a smaller capacity battery doesn’t do much to combat high electricity costs.
The new Reserva Pro, launching in October 2026, looks to fix that by expanding capacity. It will be a great option for the right homeowners, but it’s not designed to suit everyone, particularly those after simple backup power or the kind of features you’d find in similarly priced products like Sigenergy or Tesla.
Pros:
- European engineered
- Longstanding company
- Perfect fit for homes with the Fronius inverter
- Reliable and built to last
- Strong safety and data regulations
Cons:
- Price point towards high end of market
- Less features compared with Sigenergy and Tesla
The two Fronius batteries available in Australia: Fronius Reserva and Reserva Pro
Right now, homeowners have two options: the Reserva, available today, and the Reserva Pro, landing in October 2026. They’re built for genuinely different needs.
The Reserva is the obvious choice if you’re already running a Fronius Gen24 inverter, single or three phase. It slots straight in, with no extra hardware and no rewiring. It’s also refreshingly slim, at just 170mm deep, so towers can sit side by side or front to front, which helps if your garage or wall space is tight.
Its main limitation is capacity. A single tower gives you 9.45kWh on single phase or 15.75kWh on three phase, a sensible size for the European market it was originally designed for, but on the smaller side for most Australian households, who these days are after somewhere in the 20 to 30kWh range. To get there with the Reserva, you’re often looking at two or three towers, which eats into that slim profile advantage and adds to the cost. On new installations, it also tends to cost more than equivalent capacity alternatives, simply because of how the modules are sized.
The Reserva Pro is Fronius’s answer to that gap. It 3.98kWh modules can be scaled to 5 modules on single phase, around 20kWh, and 8 modules on three phase, around 32kWh. You can combine up to 4 stacks to reach circa 80kWh single phase or a genuinely commercial grade 128kWh three phase, opening the door to larger homes and light commercial applications. It also moves power in and out more quickly than the Reserva, which matters if you’re on wholesale electricity pricing or chasing free power windows, and its backup capability steps up from 35A per phase to 50A per phase, with a 63A bypass mode following shortly after release.
Manufacturing for the Pro has moved back to Austria, and its servers are based in Europe too, which means it falls under GDPR, some of the strongest data protection standards in the world. The trade off is size. At roughly 400mm deep compared to the Reserva’s 170mm, towers need to sit side by side rather than stacking front to front, so it’s worth factoring into your space planning.
A quick honesty check. At the time of writing, some final details on the Pro, most notably the battery chemistry, haven’t been confirmed publicly, though it’s expected to be LFP (lithium iron phosphate). We’ll update this once Fronius releases full specs.
Can I add a Fronius Reserva to my existing Fronius inverter?
| Feature | Fronius Reserva | Fronius Reserva Pro (Oct 2026) |
| Single phase max capacity | 9.45kWh per tower | Up to ~20kWh (5 Modules) |
| Three phase max capacity | 15.75kWh per tower | Up to ~32kWh (8 Modules) |
| With Verto Plus inverters | 15.75kWh per tower | Up to 80kWh (single) / 128kWh (three phase) |
| Depth per tower | 170mm, towers stackable front to front | ~400mm, towers stackable side by side only |
| Charge/discharge speed | Determined by the Inverter with a 32A Maximum | Determined by the Inverter with a 50A Maximum -suited to wholesale pricing and free power windows |
| Backup | Non-UPS(Instant) , essential loads focus, needs extra equipment for full backup | 50A/phase, plus 63A bypass shortly after release,extra equipment for full backup |
| Manufacturing | China | Austria |
| Data governance | Not specified | Europe based, GDPR covered |
If you already have a Fronius Gen24 inverter, this is probably the first thing you want to know, and the short answer is yes. The Reserva was designed specifically to pair with the Gen24 range, on both single and three phase, so there’s no need for extra hardware or rewiring.
The one thing worth checking first is which version of the Gen24 you have. Some homes already have a Gen24 Plus, which is battery ready out of the box. If you have the standard Gen24, you’ll likely need a software update before it can talk to a battery, which is a straightforward job for your installer but does add a small cost on top of the battery itself. It’s worth asking your installer to check this before you get a quote, so you know exactly what you’re paying for.
If you’re not sure whether your setup needs an inverter upgrade at all, our guide on do you need a new inverter to add a solar battery walks through AC and DC coupling in more detail.
This is also why the Reserva is showing up in a lot of retrofit conversations right now. A wave of Gen24 owners are upgrading to bigger battery systems as part of the current rebate period, and for anyone in that position who doesn’t want to replace a perfectly good inverter, the Reserva is often the simplest way to add storage without starting from scratch.
What does a Fronius battery cost?
As a European manufactured product, Fronius batteries sit at the premium end of the market, in similar territory to Tesla and Sigenergy rather than the more affordable Chinese brands. Exact pricing for the Reserva Pro hasn’t been released yet, and the Reserva’s price varies depending on how many towers you need to reach your target capacity, so the best way to get an accurate figure is a quote based on your own usage.
What we can say is that the federal battery rebate makes that premium price point more achievable than it used to be. The Cheaper Home Batteries Program currently takes around 30 percent off the cost of a home battery, and that applies to the Reserva the same as any other eligible system. If cost is the main thing holding you back, it’s worth getting a quote with the rebate applied before ruling Fronius out.
For the full breakdown of eligibility and how to apply, see our guide to the 2026 solar battery rebate.
One thing we can’t confirm yet: Fronius hadn’t published official Australian warranty terms for the Reserva Pro at the time of writing. We’ll update this once they’re confirmed, but it’s worth asking your installer directly for the product and labour warranty periods before you commit, particularly given how much weight Fronius’s reputation for longevity carries in this decision.
How does Fronius stack up against other solar battery brands like Tesla or SigEnergy?
Being a European manufactured product, Fronius was never going to compete on price with the Chinese battery brands, and that hasn’t changed with the Pro. What the extra capacity does is move Fronius into the same conversation as Tesla and Sigenergy, rather than sitting in its own smaller category. Whether that positioning is justified will become clearer once full Reserva Pro pricing lands, but it will likely land in the top end of the market.
On features, it’s a similar story to the inverter side of the business. Fronius has never been the most feature packed option, and it isn’t trying to be. If you want a battery that leans into flexibility, smart scheduling, and a broader feature set, a brand like Sigenergy will likely feel more geared toward that, and it’s worth reading our Sungrow vs Sigenergy battery review to see how that comparison plays out. If what you want is a battery built by a company with a long track record of reliable, well engineered equipment, Fronius holds its own against anyone in that conversation, including Tesla and Sigenergy. For a wider view of how the premium brands stack up against each other, our best home batteries in Australia guide covers the full field.
Who a Fronius battery actually suits
If you already own a Fronius Gen24 inverter, have adequate installation space, and your needs sit comfortably in the 10 to 15kWh range, the Fronius Reserva is a proven, excellent choice available right now. Planning something bigger? If you need faster charge and discharge for wholesale pricing, or you’re eyeing a light commercial setup, the Reserva Pro is worth the wait when it lands in October — just keep its deeper footprint in mind as you plan your install space.
One thing worth checking before you go further: not every Gen24 inverter is battery-ready out of the box. The Gen24 Plus comes ready to go, but other Gen24 models need a software update, typically around $1,000, to unlock battery compatibility. It’s well worth confirming which one you have before putting down a deposit on a new battery system.
Beyond the technical fit, there’s also the question of who Fronius is as a brand. If European manufacturing, strong data governance, and a genuine track record for reliability matter to you more than having the widest possible feature set, Fronius deserves a place in the conversation regardless of which model suits your capacity needs.
Where Fronius is less likely to be the right call: if you’re chasing the lowest cost per kWh, want the most feature-rich or flexible system on the market, or need a simple, fully self-contained backup solution without extra equipment.
Here’s the thing, though — the real risk in this industry was never picking the “wrong” brand. It’s skipping the process that figures out what you actually need. A good installer should be mapping your 24-hour load profile across all four seasons, thinking about where your household is heading (more people, an EV, maybe a pool), and getting clear on exactly what you want from backup power and other features — all before any product name even enters the conversation.
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