Great! Rsync is your beast and is is well worth the learning curve, (there are many options). I wouldn't bother with worrying about your find modified last 2 days requirement either, since rsync will check for modification (which achieves more or less the the same, cuts down on what is transfered and only copies files that have been updated compared to destination).
rsync -va srcdir destdir
I added the -v for verbosity only so you can see what's going on. if your were copying remotely (over internet to a remote computer) then --progress will show progress during the copy of each individual file.
If you want to exactly match your directory, ie. if you want rsync to remove files on destination that are no longer on source (because they've been deleted) this is possible as well with
--delete, but I think you are creating an archive so I didn't use that in the example.
Further options depend on your specific requirements (follow links ? etc). I'll leave that to you to choose
You can give it include lists, exclude lists, as well in case you're copying a development area which might contain backup files from editors.
Summary of archive options
-a, --archive archive mode; equals -rlptgoD (no -H,-A,-X)
-l copy symbolic links as symbolic links
-p preserve attributes
-t preserve times
-g preserve group
-o preserve owner
-D preserver devices (must be super user to work)
If you are copying between machiens then your need to consider time synchronisation or fuzzy time matching but you are copying onto sd card on one computer so no need to worry.
If you really want to use
rsync can take a list of files from a file with
--files-from in which case the -r (recursive) option of archive mode is not respected.
find . -mtime 2 | rsync -av --files-from - srcdir destdir
But please read the manual page since
--files-from has side affects, and I thought there was too much to copy into this answer.
If your destination might be updated somewhere else you can add,
-u, --update skip files that are newer on the receiver