What size battery should you buy under the 2026 tiered rebate?
Since 1 May 2026 the federal battery rebate is tiered on usable capacity, and it changes the answer. Bigger is no longer automatically better value, and there is a cliff most quotes still do not mention. This guide is brand-neutral.
Written by Juan Flinn, Content Editor · Reviewed by the Mission Green Energy Team · Updated August 2026
Three tiers, on
usable capacity.
The rebate is calculated on usable capacity — the figure on the Clean Energy Council register — not the nominal number on the brochure. The two are usually different, and the gap matters when you compare quotes.
First 14 kWh usable — full rate
14–28 kWh usable — reduced
28–50 kWh usable — the cliff
Why 28 kWh is
the number to know.
Below 28 kWh usable, every module you add is still meaningfully rebated. Above it, you pay close to full price for capacity earning 15% of the rate. For most households the practical sweet spot sits at roughly 27–28 kWh usable — the last point where the maths still works in your favour.
Small system, ~13.75 kWh usable
Sits entirely in the full-rate tier. The best rate per kilowatt-hour you can get — but the smallest total benefit.
Mid system, ~19.25 kWh usable
Full rate on the first 14, then 60% on the rest. Still strong value.
Large system, ~27.5 kWh usable
Captures the entire full-rate tier and almost all of the 60% tier. Usually the most total rebate before the cliff.
What this means
for your home.
- Gas cooking and heating, modest evening use? A system in the 10–14 kWh usable range often covers the evening peak and sits entirely in the full-rate tier.
- All-electric, induction and heat pump? The 19–28 kWh usable band is usually where the value sits, because the 60% tier still carries most of the cost.
- All-electric with an EV charging at home? Push toward the top of the 60% tier — around 27–28 kWh usable — before the cliff makes extra capacity expensive.
- Thinking of going bigger than 28 kWh usable? Do the sums first. Above the cliff you are paying near full price. Sometimes it still makes sense; often it does not.
Rebate values move with the small-scale technology certificate price, so treat any dollar figure as indicative. What does not move is the shape of the tiers — and that is what should drive your sizing.
Two things worth reading alongside this: usable vs nominal capacity, because the rebate is paid on the smaller number, and how to check a battery brand before you buy if you are weighing an unfamiliar name. You can also check every current federal and state incentive, each linked to its official source, with our free rebate checker. If you want it modelled against your actual bill, book a free assessment.
Your questions,
answered.
From 1 May 2026 the rebate is tiered on usable capacity: 100 percent of the base rate on the first 14 kWh, 60 percent from 14 to 28 kWh, and 15 percent from 28 to 50 kWh. Eligible systems must be between 5 and 50 kWh usable. Values move with the small-scale technology certificate price.
Usable capacity, as listed on the Clean Energy Council approved battery register. This is often lower than the nominal figure quoted in brochures, so check that any quotes you are comparing use the same basis.
For most all-electric households the practical sweet spot is around 27 to 28 kWh usable — the last point before the rebate drops to 15 percent. Smaller homes with gas cooking and heating often do better in the 10 to 14 kWh range, which sits entirely in the full-rate tier.
Sometimes, but do the sums. Above 28 kWh usable the rebate falls to 15 percent of the base rate, so you pay close to full price for the extra capacity. It can still make sense for very high consumption or off-grid-leaning setups, but it is no longer the automatic value choice.
What applies
where you live.
The tiers above are federal and apply everywhere. What stacks on top of them is not: battery rebate NSW covers the VPP incentive and the Home Energy Saver loan, battery rebate QLD covers why there is no state scheme, battery rebate WA covers the Synergy/Horizon split and the mandatory VPP, and Victorian solar rebates covers Solar Victoria.