As more Australians turn to solar batteries to cut electricity costs and gain energy independence, one question always comes up: what size battery do I actually need?
The right battery size depends on your household energy use, solar system size, and lifestyle. Start by reviewing your electricity bill to find your average daily consumption. A small home might use 10–15 kWh per day, a medium home 20–25 kWh, and a large family home 30+ kWh. However, you only need to store enough energy for your night-time use, which is usually 30–50% of your daily total. If your main goal is to reduce evening electricity bills, a 5–7 kWh battery is often enough. For greater energy independence or blackout protection, aim for 10–13 kWh. Larger homes or those with EV charging might benefit from 13–20 kWh.
Your solar system size also plays a role. A 6.6 kW solar setup typically pairs well with a 10 kWh battery, ensuring it can fully charge each day. Oversizing your battery without enough solar generation can reduce efficiency and increase payback time. If you’re planning future upgrades like an EV, pool, or home office, consider a modular or expandable battery to keep up with your energy needs.
At Equity Solar, our Clean Energy Council–accredited team helps homeowners choose the right system size to maximise self-consumption and long-term savings. With expert design and honest advice, we’ll make sure your solar battery is the perfect fit for your home today and in the years to come.