Well... I have to back him up some what on the batt termanels.
When it comes to the alternator and the negative side of the batt. The more efficant your batt is translates into less wasted charge. That meens that your coil pack can genorate more of a punch. as so long as you have good sparke plug wires/cables. Then to top it off that wasted spark gets grounded via your engine block .. threw the chassie of the car . and bam back into the batt. Basicly if you create a better path of flow, The whole charging/spark/timing system will be more efficent. More of a spark meens more fuel that can/is being burnt. More air/fuel/spark more power. BUT! just changing the the termanols alone is really only 1-3ohms/and fractions of 1 volt less resistance then stock, meening nothing truly gained. what your probably feeling is the smoother oil and the fact that your fuel pump is geting the proper amount of gas through. meening yea some power/idle was gained, but nothing over stock.
But i might be wrong... only the g-tech/dyno tells