So i just moved everything from my 4GB SDHC to my ex-phone Micro SDHC 16gb card, got an MicroSD adapter (ADATA), put it into my 3DS and... nothing happened, but tried my old 4GB SDHC and everything seems to work fine...

So, should i forget and get a 16/32gb SDHC or try again with another Adapter (maybe another company, Kingstone, Samsung?) ? Does anyone here uses their 3DS with a micro SD ?

my micro-sd cards work.
be sure to format it to 32 or whatever it is called

I know some people can use SDXC Cards in their systems, but they need to be formatted to FAT32 and they're prone to crashing. I'd just get a 16 or 32 GB SDHC and be done with it, rather than fuss around (and probably spend even more money in the process) with Micro SD adapters.

got it to work, it was on FAT32 but decided to format it again, and now it works

EDIT: wow... 100k blocks, feels like theres no way i could fill that up lol

yeah i also have a 16gb sd.card.
still have all the demos and trailers and nes and gba games plus a few 3ds eshop games