Broken down college kid

Just a quick question for those of you out there. After I replaced the ECU and put in a new coil the car starts up no problem now. BUT I noticed while increasing acceleration or RPMs the ammeter shifts to the right quite a bit on the + side of the gauge. Would this be due to the battery losing some charge throughout our whole attempt at getting the car started and cranking the engine, so the gauge needle showing an increase in + would indicate the battery charging from the new alternator after running on the bad alternator for a little bit before my issues started ?