Yes, you can purchase a replacement battery for the VL-Z1 camcorder here: http://www.zbattery.com/Lenmar-replacement-battery-for-the-Sharp-BT-L226U
Our policy, listed below, would not allow for us to send a single battery to Australia. So if you want only 1 battery you would have to find a seller in Australia that sells a similar battery, or if you have a friend in the US we would send it to them and they would send it to you.
Here is our policy for international orders taken from our shipping and handling policies page (http://www.zbattery.com/Shipping-Handling-Policy
): INTERNATIONAL ORDERS
We have an order minimum of $150 for International orders. All International orders MUST be insured. We are not responsible for any brokerage, duties or taxes your country may charge you before releasing your order. We may require a wire transfer for International orders over $300. Wire transfer fees may apply. If you would like to order for International shipping, please contact us at 1-800-624-8681. Please provide your billing and shipping address and what you'd like to order. We will send you a credit card charge authorization form for you to fill out and return or we will send you the details for the wire transfer if your order is over $300 USD. We reserve the right to reject any International orders.
Karl - Zbattery.com