Same Capacity, More Power – The Surprising Trend in Battery Size - SunWiz

When it comes to batteries, size matters — but the ideal size depends heavily on location, system configuration, and subsidy parameters.

Unlike PV systems, which have steadily grown larger over time, battery capacity has fluctuated, shaped by a mix of market forces, policies, and price sensitivity. For manufacturers and retailers, this makes product-market fit more nuanced than ever.

📊 What the Data Shows: Average Battery Sizes

The 2025 SunWiz Annual Australian Battery Market Report reveals that average battery capacity in 2024 remained close to 2023 levels. But that stability masks important variation beneath the surface:

Retrofit systems typically use smaller batteries, especially when space, price, or compatibility are constraints
Some states buck this trend, influenced by local program design and subsidy tiers
Meanwhile, the “one-shot” nature of the federal battery subsidy is expected to push many customers to maximise capacity in a single purchase, whereas affordability-driven buyers tend toward the lowest sticker price, often opting for smaller capacities

⚡ Battery Power Is Climbing

While energy capacity has remained relatively flat, battery output power has steadily increased:

Most batteries in the market now deliver 5kW of continuous power
7kW and 10kW models are gaining popularity
11kW systems are beginning to emerge

This trend reflects growing consumer expectations around load coverage and backup performance — and presents a strategic opportunity for brands that can offer higher output systems without sacrificing cost competitiveness.

🧭 Why This Matters for Your Strategy

Understanding battery size preferences by market segment and state is critical for:

Product design and positioning
Stocking and logistics planning
Installer training and commissioning procedures
Pricing and marketing strategies tied to local subsidies

Brands that align their product mix with the reality of regional incentives and customer behaviour will win more deals — and grow their share in a fast-changing market.

📘 Go Deeper with SunWiz

The 2025 SunWiz Annual Australian Battery Market Report offers a detailed breakdown of battery sizes, including how they vary by:

Installation type (retrofit vs new build)
Geography
Output power
Popular configurations

SunWiz’s Battery Market Subscription also includes monthly updates on evolving trends in battery power, voltage, capacity, and warranty periods.

👉 Purchase the Annual Report or subscribe to our monthly battery market updates

Interval Meter Data Tool Disclaimer

The Interval Meter Data Tool is designed to convert standard form meter data for the OpenSolar platform.

Users are responsible for meeting the requirements of the data that needs to be uploaded to the tool, which extends to but is not limited to

The completeness and accuracy of the data
Ensuring that there are no missing records
Uploading the data in one of the compatible intervals (15m, 30m or 1h).

Data uploaded to the Interval Meter Data Tool should not contain multiple datasets. In the case an excel file is uploaded, only the first sheet will be considered.

The accuracy of the output is dependent on the user’s dataset, therefore SunWiz does not guarantee the accuracy of the output.

The user must acknowledge that the output of the tool is beyond the control of SunWiz, and they must ensure that the data is accurate on their own behalf.

In the event that the program runs into an issue, the user will be issued with warnings or solutions to address or resolve the issue.

If the user requires additional support, they can avail it as a separate service from SunWiz

Warranties on performance

The Interval Meter Data tool from SunWiz attempts to convert most frequently occurring types of standard meter data file types in specific formats for the purpose of being used on the OpenSolar platform. Unless mentioned otherwise, SunWiz does not extend any guarantee of any kind, either expressed or implied, on the limited success of the Interval Meter Data Tool and the extent of it’s automation. Depending on the user’s upload, the program may require additional inputs, the training for which is not included in the purchase of this service and can be purchased separately.

Input requirements

The Interval Meter Data Tool accepts data in the 15-minute, 30-minute and 60-minute(hourly) intervals. In case the file is uploaded in an excel format (*.xls, *.xlsx, *.xlsm), only the first sheet of the file will be considered. Our tool is required to accept raw meter data, usually highlighted as ‘E’ data in its standard format; and therefore SunWiz does not guarantee that all data formats will be accepted.

For complete automation, the file must adhere to an acceptable standard format. In the case of an issue, the user will be provided with instructions by the tool on how it can be resolved. Warnings will be issued if the data is incompatible, incomplete with missing records and if multiple datasets are uploaded at once.

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Same Capacity, More Power – The Surprising Trend in Battery Size