From our research, it seems that we need an external hard drive with ac power but not greater than 2tb. This is proving bloody hard to find!!! Has anyone had success in using something different?
Below is from Nintendo support (American site) and there's a list of drives that I can't find locally - ugh.
"To ensure maximum performance between your Wii U and an external storage device, we recommend using a hard-disc drive (HDD) with a dedicated power source (i.e., using an A/C adapter). Due to the wide range of external storage devices, usability and performance will vary."
Help!
You could probably buy an external HDD enclosure & add your own 1-2TB HDD
Example of enclosure
https://www.scorptec.com.au/product/hard-drives-&-ssds/enclo…