How to save with a home battery: what to check before buying

A home battery stores energy for later use. Whether it reduces costs enough to justify the investment depends on your property and electricity plan. Start with evidence from your bills and monitoring rather than choosing the largest advertised capacity.

Five inputs for a useful assessment

• How much surplus solar is available to charge the battery?
• How much electricity do you normally import after solar generation falls?
• Which import rate would stored energy avoid, and which export credit would you give up?
• What usable capacity and charge/discharge power does the selected system provide?
• What installation costs, operating losses, reserve settings and warranty conditions apply?

Capacity and power answer different questions

Capacity in kWh describes an amount of stored energy. Power in kW describes how quickly energy can be delivered. A system can have enough capacity for the evening but still be unable to run every large appliance simultaneously.

Ask for the assumptions in writing

Request a comparison showing your existing situation, the proposed setup and sensitivity to changing tariffs. Ask how cloudy weather, seasonal loads and battery degradation are considered. Keep estimated savings separate from any guaranteed contractual performance.

Understand optional arrangements

Grid charging, time-based export and virtual power plant participation may change the economics. Check your retailer’s terms, export approvals, battery warranty and how much control an operator has before signing up.

Plan for compatibility

Discuss the exact inverter, battery model, usable capacity and whether your existing solar is suitable. Backup is a separate design question. Ask which circuits would be supported and what additional equipment is included.

Australian Government: solar and battery bill savings

Request a battery assessment · Battery installation information · Warranty Q and A

Reviewed 2 October 2026. General information; financial outcomes depend on the system, usage and tariff.