My sparges for ag batches take about 1 hour. If you go too long, you will extract tannins and such from the husks of the grains. Depending on the batch (starting gravity), you can also take sparging down to a gravity of about 1.010, for a normal 5-gal batch. Of course, with a stronger batch, you will take it to a higher gravity. For a normal strength batch, I will run about 4 gallons total sparge through.
need more info. fly sparging is much slower, to avoid stuck sparge and pH issues
batch sparge is faster, shouldn't get stuck in most cases, and typically won't have pH issues unless you have pretty whacky water chemistry to start with.
my batch sparges typically take less than 10 minutes, and that's with a SS braid and 5 gallon batches.
as I understand it, fly sparging is more like 30 mins for a 5 gallon batch, 45+ for 10 gallons.
but those are just averages. some people really trick out their brew systems and have fast sparges, no tannins and amazing efficiency.