How the Fronius Reserva works
The Reserva is a high-voltage, DC-coupled battery that connects to a compatible Fronius hybrid inverter. The inverter manages the solar array and the battery together: during the day, surplus solar charges the battery; at night or on cloudy days, the battery discharges to the house. Everything is visible in the Fronius Solar.web app, from the battery’s state of charge to how much solar you’re generating and using.
Inside the cabinet, the battery uses lithium iron phosphate (LFP) cells. Each Reserva is built from stackable modules: 2 modules give 6.31 kWh usable, 3 give 9.47 kWh, 4 give 12.63 kWh and 5 give 15.79 kWh. If one battery isn’t enough, up to 4 Reservas can run in parallel on a single compatible inverter. The enclosure is IP65-rated and the operating range is -20 to +55°C, so it can be installed outside on a shaded wall, or indoors in a garage or plant room.
Which Reserva size suits your home
Start with how much power your home uses between sunset and sunrise, because that’s the gap the battery fills. Your Synergy bill or the My Account app will show it. Add a margin for cloudy days and for anything you plan to add later, such as an EV or a second air-conditioner.
For example, a home using around 9 kWh overnight sits comfortably on the Reserva 9.47 kWh (3 modules) with a little headroom. Smaller households who mainly want to store surplus solar they’d otherwise export often start with the 6.31 kWh unit (2 modules) and add a second Reserva later if needs grow.
- Your inverter. The Reserva only works with the Fronius Primo GEN24 Plus SC, Symo GEN24 Plus SC or Verto Plus. If you already have a GEN24 Plus SC, you can add a Reserva to it; if not, factor in an inverter change.
- Where it goes. We check wall support, floor space and airflow at the site visit.
Reserva sizes
Reserva 6.3
Reserva 9.5
Reserva 12.6
Reserva 15.8
Fronius Reserva at a glance
Rebates on a Fronius Reserva in Perth
The Reserva is listed by Fronius as qualifying for the federal Cheaper Home Batteries Program. The main points to know:
- Federal Cheaper Home Batteries Program: applied up front, reducing the installed cost per kWh of usable storage. Your install date sets the rate that applies.
- WA Residential Battery Scheme: for Synergy customers, the rebate scales with usable capacity up to 10 kWh, and any Reserva size reaches that cap. It requires a Virtual Power Plant (VPP) commitment with Synergy.
- Synergy Supported Solutions List: the WA rebate requires the product to be on this list. Fronius does not currently publish the Reserva’s entry status, so we confirm this with you before you sign.
Works with
What installation involves
Site and switchboard assessment
We inspect your existing solar system, switchboard and the proposed location. We then recommend a capacity and a position that stays accessible and within the manufacturer temperature guidelines. Any switchboard change needed is raised at this visit.
Inverter compatibility check
We check whether your existing inverter works with the battery directly or needs changing. You receive a clear outline of the battery, any inverter changes and how the parts work together before any work begins.
Choose your backup circuits
A battery only supplies power in a blackout if it is set up for backup. You choose between essential circuits only or a wider set, and what stays powered depends on battery capacity and wiring.
Installation day
Technicians mount the unit in a shaded, ventilated position, install isolators, and route cabling between the array, inverter, battery and switchboard. They integrate the battery with your solar set-up and test every connection before commissioning.
Network approval and documentation
The installation is documented and connected to meet Australian standards and the requirements of Western Power, the network operator in the Perth metropolitan area. Isolators, testing and documentation are provided for meter approval.
Commissioning to AS/NZS 5139
We commission the system to the relevant Australian standards, including AS/NZS 5139. We set the charge and discharge settings, connect monitoring and confirm the battery stores and releases energy correctly.
For how this kind of job is planned, wired and commissioned, see our home battery installation service.
Things to know before you buy
Pros
LFP chemistry with a strong safety profile. The lithium iron phosphate cells are well-suited to home storage and have a long operating life.
Choose from 6.31, 9.47, 12.63 or 15.79 kWh, and stack up to 4 batteries in parallel if your needs change later.
Rated for outdoor install. An IP65 enclosure and a -20 to +55°C operating range suit a shaded Perth wall or garage exterior.
Rebate-eligible. Fronius lists it for the federal Cheaper Home Batteries Program, which lowers the upfront cost per kWh.
One app for the whole system. The Fronius Solar.web app shows solar, battery and household use in the one view.
Things to consider
Inverter compatibility is the first thing to check. The Reserva only works with a Fronius GEN24 Plus SC or Verto Plus inverter. If you have an older Fronius inverter (or another brand), budget for an inverter change as part of the battery job.
Backup isn’t automatic. A battery only supplies power during a blackout if it’s set up for backup, with selected circuits wired through the inverter’s backup output. Decide at quote stage which circuits you want to keep running, not after install.
The larger units are heavy. We check this on site.
The manufacturer doesn’t publish a headline warranty term. Warranty length, round-trip efficiency and cycle-life figures aren’t stated on the Fronius Reserva material. We go through the current warranty document with you before you sign, and warranty support runs through your installer.
Internet connection matters for monitoring. The Solar.web app and remote diagnostics rely on the inverter staying connected to your home network. We set it up on install day; keep it online so performance can be tracked.
Fronius Reserva questions Perth homeowners ask
How much does the Fronius Reserva battery cost?
The Reserva is priced as a complete system, which includes the battery, a compatible Fronius GEN24 Plus SC or Verto Plus inverter and installation. Perth pricing for your home comes with a written quote after a site visit.
What capacity is the Fronius Reserva?
It comes in four sizes: 6.31 kWh (2 modules), 9.47 kWh (3 modules), 12.63 kWh (4 modules) or 15.79 kWh (5 modules) of usable capacity. You can also run up to 4 batteries in parallel if you need more.
Is the Fronius Reserva eligible for the battery rebate?
Yes. Fronius lists the Reserva as qualifying for the federal Cheaper Home Batteries Program, which reduces the upfront cost. We confirm your exact model and configuration before you sign.
What inverter does the Fronius Reserva work with?
The Reserva only pairs with a Fronius Primo GEN24 Plus SC, Symo GEN24 Plus SC or Verto Plus inverter. Homes with an older Fronius inverter will need an inverter upgrade as part of the battery install.
How many Fronius Reserva batteries can I install?
Up to 4 batteries can run in parallel. With the largest 15.79 kWh unit that gives you a meaningful amount of usable storage, enough for most homes planning for an EV or significant overnight loads.
Get a Fronius Reserva quote
Sources
Last updated November 2026.