The Cheaper Home Batteries Program delivers its discount through small-scale technology certificates (STCs): the more certificates a battery creates, the bigger the point-of-sale discount an installer can pass on. Until 30 April 2026, every kilowatt-hour of usable capacity from 5 to 50 kWh earned certificates at the same rate. The program page now states it plainly:
"The STC Factor now tapers according to the amount of capacity installed: From 0 kWh up to 14 kWh (inclusive): STC Factor applied at 100%. Every kWh greater than 14 and up to 28 kWh (inclusive): STC Factor applied at 60%. Every kWh greater than 28 and up to 50 kWh (inclusive): STC Factor applied at 15%."
Batteries up to 100 kWh remain eligible for the program, but no capacity above 50 kWh earns any support. The government describes the change as recalibration rather than a cut: the stated aim is to keep the discount at "around 30%" of upfront cost at each capacity level as battery prices keep falling.
What the tiers do to a real quote
The percentage that matters to your quote is how much of your battery's capacity earns certificates, compared with the old flat treatment. That is pure arithmetic from the published tiers:
Worked example: capacity credited under the tiers
| Usable capacity | Credited capacity | Share of flat-rate treatment |
|---|---|---|
| 10 kWh | 10.0 kWh | 100% |
| 13.5 kWh (a common single unit) | 13.5 kWh | 100% |
| 20 kWh | 17.6 kWh | 88% |
| 30 kWh | 22.7 kWh | 76% |
| 45 kWh | 25.0 kWh | 55% |
| 60 kWh | 25.7 kWh | 43% |
Assumptions: credited capacity = 100% of the first 14 kWh + 60% of capacity from 14 to 28 kWh + 15% of capacity from 28 to 50 kWh, per the DCCEEW program page as at 4 July 2026; nothing above 50 kWh is credited. "Share of flat-rate treatment" = credited capacity divided by usable capacity, rounded to the nearest whole per cent. The dollar value of a certificate moves with the STC market, so we deliberately do not print a dollar figure here: convert your own system's capacity using the REC Registry's STC calculator, which the program page itself points to.
Two things follow. For the large majority of households, whose batteries fit at or under 14 kWh, nothing changed on 1 May: the discount works as it did before. For the growing number of quotes above 14 kWh, and the CER data shows the average install reached 36 kWh in April, the discount per kilowatt-hour now falls away as the system grows, and a quote that applies one flat percentage across a 30 or 40 kWh system is using last year's rules.
How to sanity-check a battery quote now
- Ask the installer to show the STC line as a separate item, with the number of certificates and the price per certificate they are crediting.
- Check the certificate count yourself with the REC Registry calculator for your battery's usable capacity and your install date.
- Remember the program requirements sit alongside the discount: the program covers batteries from 5 to 100 kWh attached to new or existing solar, and state schemes stack on top in some states (the current state-by-state position is here).
- Treat "30 per cent off" as a design aim the government states for typical systems, not a promise about your quote. The tiers above are what is actually legislated into the certificate formula.
The program has changed before: in December 2025 it was expanded from an estimated $2.3 billion to $7.2 billion over four years. We will report each further change as it lands.