Trouble transferring save file from R4DS to R4i 3DS

I'm very new to all of this, and I expect (and hope) that my issue has an easy solution. However, after spending all day researching (and even asking in another forum), I just can't seem to figure this out.I'm trying to transfer my Pokemon Black save file from my old R4 to the R4i 3DS (r4ids.cn). The file size is 512kb, and the extensions match (.nds.sav). But every time I start the game, I'm only given the option to start a new save. I can see my save file there in the menu, but it just doesn't seem like the game is reading it.I've tried using .sav, and changing the settings several times. I've tried starting a new game and overwriting that save, with the exact same name, etc. I've tried reformatting my SD card.I'm on the NDSLite, so hopefully updates aren't an issue here. I bought the same cart for my boyfriend, who is on a DS, and I couldn't get his Pokemon White save to work on his new card, either.Any help is greatly appreciated! I've been pulling my hair out over this one all day. I'd hate to have to start my Nuzlocke over from the beginning ;)

you need to convert the save file. there's an online converter mentioned on these forums somewhere.

Thank you for the reply. I've seen the converter, and even played around with it and tried a few things, but I don't understand what I'm converting or why. There is no option for R4i, or anything other than "R4". So the only option listed would be for me to convert from R4 to R4... doesn't seem like that'd do anything. In fact, when I try it, I just get an error saying I don't need to convert.As I stated, the files (old save and new saves that get generated every time I start the game) are already the same size (512kb). The completely blank new saves (when I quit without saving) are 512 bytes, so I even tried converting my old save to that size, and that didn't work. So if converting it really is what I need to do, I need more specific options/instructions, if possible :/