What drives battery prices
- Usable capacity (kWh) — the biggest factor.
- Brand and chemistry — most home batteries now use lithium iron phosphate (LFP).
- Inverter — a hybrid inverter may replace your existing one; an AC-coupled battery adds its own.
- Backup — gateways, changeover and switchboard work for blackout protection.
- Installation — location, cabling, wall or floor mounting, and any required fire-safety clearances.
How the federal discount is calculated
Under the Cheaper Home Batteries Program, an eligible battery creates small-scale technology certificates (STCs) based on its usable capacity. From 1 May 2026 the calculation is tiered:
| Usable capacity band | Share of the full certificate factor |
|---|---|
| 0 – 14 kWh | 100% |
| Above 14 kWh, up to 28 kWh | 60% |
| Above 28 kWh, up to 50 kWh | 15% |
The certificate factor itself also steps down over time, and the dollar value of each certificate moves with the market. The installation date decides which rules apply.
Worked example (illustrative numbers)
To show how the tiers work, assume a full factor of 8 STCs per kWh and $38 per STC. These are round numbers for illustration — your installer will use the current factor and price.
| Battery (usable) | Certificates | Illustrative discount |
|---|---|---|
| 10 kWh | 10 × 8 = 80 | ≈ $3,040 |
| 14 kWh | 14 × 8 = 112 | ≈ $4,256 |
| 20 kWh | 112 + (6 × 8 × 60%) = 140.8 | ≈ $5,350 |
| 30 kWh | 112 + (14 × 8 × 60%) + (2 × 8 × 15%) = 181.6 | ≈ $6,900 |
Notice how the discount per extra kWh drops sharply above 14 kWh. That's why sizing to your actual evening use matters more than ever.
Sizing sensibly
Look at how much power you use from late afternoon to morning. Your smart-meter data (from your retailer or distributor) shows this. A battery that covers most of that period, with a little headroom, is usually the best value.
State incentives
NSW offers additional battery and VPP incentives through the Peak Demand Reduction Scheme. See our battery rebates guide for details.