Plenty available at Target Sefton park SA.
Also available 2600mah $10
"Aircraft-grade anodized aluminum alloy makes the Mipow Powertube heat-sinking, durable, wearproof and corrosion-resistant. Just connect your device to the built-in female USB output port and then charge automatically. One LED indicator lets you clearly know the battery level, charging status and recharging status."
Output Voltage: Current 5V / 2.1A.
Input Voltage: Current 5V / 1A.
Battery Type: Li-ion battery.
Battery Capacity: 5200mAh / 3.7V / 19.2wh.