Hacking how much space is needed to backup wii

[lazyguy]

i have a spare 512mb card (483mb actual) and my wii is definitely not full, yet it always fails to backup
i put it back on my computer to check it, and it says it's full, but the .bin is 0 bytes

also, there are 2 (black) bad sectors when dumping; is that the sd card?

i'm pretty sure there's nothing wrong with it because i've used it without a problem all this time

 

[supagusti]

You need a bigger SD Card, because the dump needs 528MB (or 553 649 152 Bytes)
That's why your nand.bin's size is 0kB

Edit:
The black bad sectors are in your Wii's nand - no reason to worry about. The wii has spare sectors and use them.