Home / Tools / Battery sizer

Battery sizer

How much battery might I need?

Get a starting point for usable capacity from how much power you use after dark, with the current federal rebate applied. A guide, not a quote.

45%
Most households use 40–60% of their power in the evening and overnight.
SUGGESTED USABLE CAPACITY
YOUR EVENING USAGE
FEDERAL BATTERY DISCOUNT
NET COST AFTER DISCOUNT
INDICATIVE ANNUAL SAVING
INDICATIVE PAYBACK

The discount applies the tiers from 1 May 2026 — full rate to 14 kWh, 60% from 14 to 28 kWh, 15% from 28 to 50 kWh. A VPP incentive may be available on top.

Your calculator result is sent with the enquiry so we can check it properly.

Assumptions used
  • Imported electricity at $0.35/kWh; feed-in credit at $0.05/kWh
  • Installed battery cost of $900 per usable kWh before rebate
  • Battery cycles roughly once per day, limited by your evening usage
  • Rebate at 6.8 STCs per usable kWh at $38, tapered by the capacity bands
  • Essential-circuit backup adds 3 kWh; whole-property backup adds 8 kWh
A guide, not a quote

These calculators work from published industry assumptions. They cannot see your roof, your shading, your tariff or your meter, so treat every number as a rough starting point rather than an answer. Talk to us and we'll go through it properly and put the real figures in writing.

Next step

Ready to find out what your place could do?

Every quote starts with a proper look at your bills, your roof and how you actually use power. No obligation, no cost.