1. Your bills are under $400/quarter
If your quarterly electricity bill is under $400 (so about $1,600/year), the absolute dollar savings from a battery won't justify the install cost even with the rebate. A typical 10 kWh battery saves around $600/year in this scenario, and that's before considering you may not have the consumption pattern to fully use it. Payback stretches to 8–10 years, which lands you on the edge of the warranty period.
Do this instead: Run an electricity retailer comparison first. Many WA households on Synergy can save $200–$300/year just by switching to Smart Home Plan if they have evening-heavy usage. That's free money before you spend on hardware.
2. You don't own the home and the landlord won't budge
The rebate is owner-only. Tenants can't claim it, even with the landlord's written permission. If the landlord refuses to install, your options run out - a battery you pay for and walk away from is worth zero to you.
Do this instead: Send them our renters and landlords article. Sometimes the maths convinces. If not, focus on reducing your own bill via retailer switching and time-of-use behaviour.
3. You're moving in the next 12 months
Battery payback is 3–6 years for most setups. Moving in under 12 months means you don't capture the savings, and the property buyer probably won't pay you a premium that fully reflects the install cost. You'd be installing for the next owner's benefit.
Do this instead: Wait until you've moved and install in the new home. If you're selling, mention "wired for battery install" as a feature - it's a real value-add without you outlaying the capital.
4. Your roof or wiring is failing
A battery install often involves significant electrical work. If your switchboard is old (asbestos-backed, fuses instead of breakers), or your roof is due for replacement, the battery install will get messy and expensive. You'll either delay the battery while you fix those, or pay much more for a workaround.
Do this instead: Sort the underlying infrastructure first. Get a switchboard inspection. Replace the roof if needed. Then install the battery - and you can do a bigger system on stronger wiring.
5. Your current solar is undersized and you're rushed
If you have a 2–3 kW solar system from 2014, a 13.5 kWh battery is too big. The solar can't fill it efficiently. You'd be exporting too little from solar and pulling from grid to charge - defeating the point.
Do this instead: Quote the solar upgrade and battery as one combined job. Most WA installers will do this and the labour overlap saves you $1,000–$1,500. Going through the whole battery process with undersized solar locks you into mediocre payback.
6. You can't be home during peak hours
Batteries work hardest by powering your evening consumption. If your whole household is consistently out from 6am to 9pm (long commutes, frequent travel, FIFO patterns), evening kWh is low. Then a battery becomes a DEBS-arbitrage device, not a consumption shifter - which still works but with much slower payback.
Do this instead: Wait until your lifestyle changes. Or install a smaller battery (8–10 kWh) sized for whatever evening load you do have, rather than chasing the rebate cap.
The honest summary
About 70% of WA homeowners running our calculator land in the "install soon" bucket. About 30% would benefit from waiting, switching retailers first, or skipping the battery entirely. We're happy with both outcomes - if 30% of visitors don't install, the 70% who do are the ones who genuinely benefit, and the site builds a reputation for being honest about it.
If you're not sure which bucket you're in, run the calculator with your actual postcode, bill and solar. The numbers will be clear.