A solar battery stores excess electricity from your panels so you can use more of your own solar after sunset, potentially reducing grid purchases. Key factors include your evening energy use, battery capacity, usable capacity, warranty, system compatibility and whether you want backup power during outages. A battery may not be financially suitable for every home, so compare its installed cost with expected savings and ask an accredited installer about sizing and installation requirements. Check current incentives through energy.gov.au and confirm any offer with the relevant government department or provider.