What Size Solar Battery Do I Need in Australia?
Find the Right Solar Battery Size for Your Home (2025 Guide)
If you’re thinking about adding a solar battery, one of the first questions is:
“What size battery do I actually need?”
The answer depends on how much power you use, when you use it, and how much solar your panels generate.
Here’s a simple guide to help you choose the right size and get the best value for your home.
Why Battery Size Matters
Getting the right size battery means:
- You use more of your own solar power instead of sending it back to the grid.
- You save more money on electricity bills.
- Your battery pays for itself faster.
A battery that’s too small won’t store enough energy for the night.
A battery that’s too big may never fully charge — so you’re paying for extra capacity you don’t need.
Typical Battery Sizes for Australian Homes
Most households in Australia install batteries around 10–13 kWh — big enough to cover the evening and early morning when solar panels aren’t producing power.
What Affects the Size You Need
How a Battery Works Day and Night
- Daytime: Your panels generate power.
- Surplus energy: Once the home is supplied, extra power charges your battery.
- Evening: When the sun sets, your home runs on stored solar energy.
- Night: If the battery runs out, the grid steps in automatically.
With the right size battery, you can power your home for most of the night and cut your electricity bill significantly.
Typical Savings by Battery Size
These savings can increase further if you join a Virtual Power Plant (VPP) or use time-of-use electricity plans.
What Happens If You Oversize or Undersize
- Too Small: You’ll still need to buy some grid electricity at night.
- Too Big: Your battery might not charge fully every day, stretching your payback period.
- Just Right: Fully charges on sunny days, powers your home overnight, and saves you the most money.
How to Pick the Perfect Size (Made Easy)
You don’t need to do the maths – Our team will model your usage and suggest the ideal capacity. At Evitech, we:
- Look at your power bills or smart-meter data.
- Check your solar system’s generation.
- Recommend the best battery size and expected savings.
- Apply all federal and state rebates for you.
Get a Free Quote and Check Your Eligibility
Call 1300 137 974 or visit www.evitech.com.au to book your assessment or request a quote.