Sonnen is a premium German home storage brand: the sonnenBatterie focuses on finish, software intelligence and a shared-energy logic. wendows is an installer: advice, installation and after-sales by our own teams, with subsidies and reduced VAT handled when the home is eligible.
Sonnen offers its battery in several modular capacities to match your installation and your energy ambitions. Here are the configurations we install most often in Belgium.
The premium entry point for storing the surplus of a small installation and covering the evenings, with Sonnen's finish and software intelligence.
The common sizing for a family home: you store the day's production to consume in the evening, finely controlled by the Sonnen software.
For heavy consumers, you extend the capacity by modules to aim for broad autonomy, depending on your consumption profile and your ambitions.
Sonnen pushes a community energy logic: optimising and, depending on the markets, sharing energy. A premium approach to explore depending on your profile.
Beyond capacity, it's the premium finish and the software intelligence that make the difference. The brand-specific benchmarks, installed by our teams.
The sonnenBatterie relies on a lithium iron phosphate chemistry, valued for its stability and longevity. A safe basis, in keeping with the top-of-the-range positioning.
The sonnenBatterie is assembled from modules: you tailor the capacity to your installation. The exact sizing depends on your production and your consumption.
Manufacturer warranty on the cycles and capacity retention, depending on the range. wendows acts as your relay for any work carried out under warranty.
Careful German manufacturing, a design built for the living space. Sonnen aims for the top of the range, from the hardware to the user experience.
The Sonnen software optimises charge and discharge according to your consumption and, depending on the markets, shared-energy logics. Control is at the heart of the brand.
With a suitable module, the sonnenBatterie can power certain circuits during an outage. The option and its scope are confirmed at sizing.
* Valeurs indicatives selon la gamme et la configuration. Les performances et garanties exactes dépendent du modèle, du vitrage et des dimensions — confirmées lors du métré.
Buying a premium battery isn't enough: its intelligence only pays off if it's well sized and configured. Our installers fit it to the manufacturer's rules, and we handle the warranty and after-sales directly.
Sonnen isn't our only string. Depending on your budget and your expectations, other brands may suit you better. Compare them, then we decide together at sizing.
An overview of the storage brands we install in Belgium: premium, LiFePO4 and all-in-one, by capacity and by budget.
See all battery brands → vs SonnenAll-in-one 13.5 kWh pack with built-in backup and the Tesla app. The other premium reference, with native grid backup.
Compare with Powerwall → vs SonnenStackable modular LiFePO4 battery, often more affordable. Worth comparing if budget comes before finish.
Compare with BYD → the guideBefore the brand, the principle: understand how a battery stores your solar surplus and cuts your bill.
All about home storage → to combineA battery only makes sense with good production. Check the sizing of your panels before adding storage.
See solar panels → the chemistryLithium iron phosphate chemistry explains the safety and longevity of the sonnenBatterie. Understand its strengths before choosing.
Understand the lithium battery →When you add a battery to your panels, you're choosing two things: a storage brand and an installer. Sonnen answers the first with the sonnenBatterie, a premium German solution: you store the day's surplus to consume it in the evening, with a finish and a software intelligence that aim for the top of the range.
The brand stands out for its energy software: fine optimisation of charge and discharge and, depending on the markets, a community energy logic where you share electricity. It's an approach that goes beyond mere storage, for those who want to control their energy precisely.
"Sonnen doesn't just sell a battery, but a way to manage your energy: that's the whole point — and the premium positioning — of the brand.
That's where our role as an installer matters. We size the usable capacity, set the optimisation modes according to your real consumption, fit it to the manufacturer's requirements and remain your single point of contact for the warranty, the commissioning and the after-sales. No buck-passing between the seller, the manufacturer and the fitter.
One contract, one person in charge. Advice, sizing, ordering the sonnenBatterie, installation, subsidies and after-sales: everything goes through wendows, from the first call until after the warranty.
On the budget side, Sonnen sits in the premium segment: the gap is justified by the finish, the software and the user experience. To get a sense of your project, start from our storage pricing page, then ask for a costed quote: it's the only way to get a fair price, sized to your installation.
The price depends mainly on the capacity, the control options and your existing installation — not just the brand. Here are starting ranges for a Sonnen installed by our teams, with subsidies deductible afterwards.
See the detailed storage price grid →* Indicative ranges for an installed sonnenBatterie, excluding specific configurations. Precise, costed estimate with your free quote.
It's a premium German brand recognised for its finish and its software intelligence, on a safe LiFePO4 chemistry. The appeal: fine control of energy. As with any storage, the result depends on the sizing and the configuration — hence the importance of an installer.
It's a logic specific to Sonnen aimed at optimising and, depending on the markets, sharing energy within a community. Availability depends on the local context: we tell you what's relevant to your situation during the study.
Sonnen sits in the premium segment: the difference is justified by the German finish, the optimisation software and the user experience. If budget comes first, more affordable LiFePO4 brands may suit you better — we discuss it at sizing.
It depends on your production and your evening consumption. Generally, ~5 kWh for a small household, ~10 kWh for a family home, and ~15 kWh or more for heavy consumers. The exact figure is set at sizing, depending on configuration.
Depending on the range, the manufacturer warranty can run up to 10 years and covers the cycles and capacity retention. wendows acts as your relay and handles the intervention. The exact terms are specified on your quote.
Reckon from around €5,500 for ~5 kWh and from ~€8,500 for ~10 kWh installed, depending on the options and your installation. Subsidies and reduced VAT deducted afterwards, depending on your region and your eligibility.
Free on-site survey, recommended range, grants calculated, a single point of contact. Describe your project in under a minute.