Due to the rise in EV adoption in Australia, there needs to be a policy to deal with spent EV batteries in a sustainable and environmentally friendly manner. Australia has no established EV battery recycling industry, as the industry considers the volume too "low" for investment. This study shows the growth of the battery waste volume on an annual basis until 2050. It uses the growth model of both BEV and PHEV to understand when a "sizeable" volume would arrive in Australia. By 2050, the modelling suggests an annual outflow of spent batteries between 500,000 and 900,000 tonnes. The model demonstrated that features like battery chemistry type, size, and lifetime significantly affected the potential values that could be extracted from recycling these batteries. The results of this study can used by stakeholders to further policymaking and inform investment.