While disconnecting the battery for a few minutes is fine it isn't really neccesary as the PCM automatically makes ajustments according to your driving style.
I recently changed sparks plugs, lowered the gap in the new plugs to .040, added Magnecor ignition cables and a 2.5-inch Mopar/Borla dual exhaust system without ever disconnecting the battery as I had done previously. I experienced absolutely no issues or concerns. After driving a couple hundread miles my car's performance was the
BEST 
it has ever been in 16K miles.
Just my two cents. [8]