Avoid Buyer’s Regret: How the Battery Size Can Make or Break Your Cheaper Home Battery Program’s Payback

The new Cheaper Home Battery Program is creating a wave of excitement among Australian homeowners. But here’s the catch: picking the wrong battery size can turn a great opportunity into a costly mistake. 

Choosing the right battery size for your solar system is just as important as the rebate itself. With generous federal and state incentives now in play, the timing couldn't be better-but only if you size it smartly. 

Cheaper Home Batteries Program: A Game Changer 

Launched in 2025, the Cheaper Home Battery Program offers eligible households, and small businesses may be eligible for around a 30% discount on the upfront cost of installing a small-scale solar battery. If you're also eligible for state-level programs, your savings could grow even further. 

Here's what the program covers: 

Around 30% off the upfront cost of a solar battery system. 

Applies to battery sizes from 5kWh to 100kWh. 

STCs are calculated based on usable capacity, capped at the first 50kWh. 

This means whether you're upgrading or buying your first system, a significant portion of the cost is already covered. Incorrectly sized battery storage would mean even the best rebate won't deliver the solar battery ROI you'd expect. 

Why Battery Size Matters: Too Small, Too Soon 

Going small to save money might seem smart, but it could backfire. A battery size for a solar system that's too small for your household needs will: 

Run out of stored energy early 

Force you to rely on expensive grid power overnight. 

Deliver a longer payback period, as your savings don’t match expectations. 

To avoid regret, it’s important to consider your solar battery storage capacity to your household’s actual electricity habits—especially usage after the sun goes down. 

The Problem with Oversizing 

On the flip side, bigger isn’t always better. Oversized batteries can be a trap: 

If your solar panels can’t fully charge the battery during the day, you’d be wasting extra unused capacity. 

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