Id say just try it.
Backup the sav file before you try.
If it doesnt work as you place the sav file you might wanna read this topic:
Its about a guy who wants to do aprox the same thing.
Only I hope you read better.
No need to convert with anything......if they are in the following format .nds.sav for the extension you just need to remove the .nds part leaving only the .sav part
In the folder of games click TOOLS in the bar across the top Click Folder Options. Click the View tab Uncheck "Hide extensions for known file types". then Click Ok.
Rename your file extension by removing the .nds part leaving it as .sav example game1.nds
.sav the part in RED
is what you need to remove leaving only game1.sav
Click anywhere in the folder away from the file your editing to complete the edit .... and repeat the process for all files named like this
Then reverse the process of hide extensions above to hide the extensions again!
If you used the AKAIO and changed the save file format to .sav then you don't have to do anything they should just work
....but as mentioned above backup all your saves before trying just in case