Solar Battery Storage: What Size Do You Really Need?
If you’re thinking of adding battery storage to your solar setup, one of the most important questions to answer is: what size do I really need? Choosing the right solar battery capacity can help you maximise your energy savings, increase your energy independence, and ensure your home stays powered when the grid goes down.
In this blog, I’ll help you understand how to estimate your battery needs — and how iStore’s scalable battery solutions make it easy to build the system that fits your lifestyle.
Why Battery Storage Matters
Solar panels generate power during the day, often producing more electricity than you use in real time. Without a battery, that excess energy is usually sent back to the grid. But with a battery, you can store that unused solar power and use it later — in the evening, during a blackout, or on cloudy days.
The right battery size ensures:
You don’t waste your solar energy
You reduce your reliance on the grid
You have power when you need it most
How to Estimate the Right Battery Size
There’s no one-size-fits-all answer when it comes to battery storage. The ideal size depends on a few key factors:
1. Your Daily Energy Usage
Look at your electricity bills to find your average daily consumption in kilowatt-hours (kWh). A typical Australian household uses between 15–25 kWh per day, but this can vary widely depending on your appliances, air conditioning, and lifestyle.
2. Your Solar System Size
If your solar panels generate more energy than you use during the day, a battery allows you to store the excess. For example, if your 6.6 kW system generates 25 kWh a day and you only use 15 kWh, you could store the remaining 10 kWh.
3. Your Energy Goals
Do you want to:
Lower your electricity bills?
Keep the lights on during outages?
Achieve full energy independence?
Each goal may require a different level of storage. For basic backup or evening use, a 5–10 kWh battery may be enough. But for larger households or off-grid setups, 20–30 kWh may be more appropriate.
Scalable Solutions with iStore
The great news is that you don’t have to get it perfect from day one. iStore’s modular battery system gives you the flexibility to start with what you need now and expand later.
Each unit is compact and stackable, with storage options that scale up to 30 kWh. This makes it ideal for:
Growing families
Changing energy usage patterns
Businesses with evolving power needs
Whether you start with 10 kWh or go all-in with 30 kWh, iStore lets you build a system that fits your home today — and grows with you tomorrow.
Choosing the right solar battery size comes down to understanding your energy usage and goals. With iStore’s scalable battery storage, you have the freedom to customise a solution that suits your lifestyle — and the peace of mind that your home will stay powered when it matters most.
Get in touch today to start our journey together.
Stay committed!
Damien Frearson
