Check the battery’s usable capacity, power output, warranty, expected lifespan and compatibility with your existing solar inverter. Consider how much electricity you use after sunset, whether you want backup during blackouts, and how your retailer’s tariffs and feed-in rates affect potential savings. A larger battery is not always better, and a licensed installer should assess your switchboard, wiring and system design before recommending one. Rebates and incentives may be available, but eligibility and amounts depend on current government rules and your circumstances, so check energy.gov.au and the relevant state program.