Solar Battery Size Calculator
Work out what size solar battery you need. Answer a few questions about your evening power use and what you want the battery to do, and the calculator returns a recommended size in watt-hours (10,000Wh is a 10kWh battery), then prices it.
Your solar battery size details
A battery mainly covers the power you use after the sun goes down.
A bigger solar system generates more surplus to charge a bigger battery.
Your estimate sits within the typical range.
Size the battery to the solar surplus you actually have and the power you use after dark. An oversized battery that never fills, or that sits empty by morning, wastes money.
Where the money goes
Estimated breakdown for your configuration
💰 Ways to save
- Match the battery to your evening usage and your solar surplus, not the biggest unit on offer.
- Check for state battery rebates and interest-free loans, which can cut the cost sharply.
or from $52/week over 5 years , indicative finance
How we estimate this
Most Australian homes suit a 10kWh to 13kWh solar battery in 2026, costing roughly $6,000 to $20,000 installed depending on size and brand. Size it to your evening usage and your solar surplus.
Pricing reviewed: October 2026.
Doing more than just solar battery size?
Build a combined estimate across every part of your project in one place.
Pricing reviewed October 2026. Indicative Australian costs, not a quote.
Understanding solar battery sizes in Australia
Most Australian homes suit a 10kWh to 13kWh solar battery in 2026, costing roughly $6,000 to $20,000 installed depending on size and brand. Size it to your evening usage and your solar surplus.
A battery stores daytime solar for use after dark. Size it to the power you use in the evening and the surplus your panels generate, an oversized battery that never fills is wasted money.
Frequently asked questions
What size solar battery do I need?
Most homes suit 10kWh to 13kWh, sized to evening power use and solar surplus. A small efficient home may need 6.5kWh; a large home with a pool or EV may suit 15kWh.
How much does a solar battery cost in Australia?
Roughly $6,000 to $20,000 installed in 2026 depending on size and brand. State rebates and interest-free loans can reduce the cost in some states.
Are you a solar / trades business?
Everyone on this page is working out what solar battery size costs because they are ready to hire. Put your business right beneath the calculator, in your state, so you are who they find. From $50/mo.