This is general information, not tax advice.
The two questions
Business owners usually ask two things about a battery: can I depreciate it, and can I write it off immediately? Both depend on the battery being installed ready for use in a business that earns assessable income.
Normal depreciation
A battery used to earn income is generally a depreciating asset, claimed over its effective life. Rules differ if the asset is partly for private use, in which case only the business portion is deductible. The harder part is the cost base. The battery was purchased partly with cash and partly by assigning STCs, and how the STC value is treated can change the amount you depreciate. Since the invoice shows the full price, the STC discount and the balance, make sure your accountant sees all three. See battery STC discount on an invoice.
Instant asset write-off
The 2026-27 Budget made the $20,000 instant asset write-off permanent for small businesses from 1 July 2026. Businesses with aggregated annual turnover under $10 million can deduct the full cost of an eligible asset costing under $20,000, first used or installed ready for use in the income year. The threshold applies per asset.
| Factor | Why it matters |
|---|---|
| Turnover under $10 million | Eligibility for the write-off |
| Cost under $20,000 per asset | Threshold test |
| Installed ready for use in the year | Timing around 30 June |
| GST treatment | Whether the cost is measured ex or inc GST depends on your GST status |
| Whether it is one asset or a system | Needs advice |
A typical small-business battery of 10 to 20 kWh often lands under the threshold after the discount, but a combined solar and battery install may not. The rebate sizes are in the battery STC calculator.
Commercial batteries and state incentives
Commercial buyers can access the federal discount as long as the battery meets the program rules. A NSW commercial battery incentive was reported to start from 1 September 2026. See battery rebate for businesses. Larger commercial solar sits under different rules; see mid-scale solar STCs.
What this means for installers
If you sell to businesses, give an itemised invoice with GST shown and the STC value on its own line. Your customer’s accountant will ask for it, and it keeps your own GST treatment tidy; see battery rebate GST treatment. The battery STCs page explains the scheme, and pricing shows what certificates are worth.
From the desk: ask the accountant before signing, not after. A purchase that tips over $20,000 by a few hundred dollars can change the year’s tax outcome.