Start by reviewing your electricity use and solar export data, then compare a battery’s usable capacity, power output, efficiency, warranty and expected lifespan—not just its headline size. Ask a licensed installer to model different options for your household, including whether the battery can provide backup during outages and whether your switchboard needs upgrades. Check where the system will be installed, how it will be ventilated and monitored, and what maintenance or replacement costs may apply. Also compare tariffs and financing carefully, as the potential savings depend on your usage, electricity prices and the final quote.