Yesterday while waiting in line after a drag car leaked all over the track for it to be reopened i noticed my battery gauge moving around a lot, it would dip down low like 10 and then bounce up to 13. then when i put it into park it seemed to stay at 13 ( not sure if that was just by chance or what) today while im driving i notice it bounces around as well. except for it drops and then goes high like 14. any clue on what this could be ? i just replaced the battery no less than a month ago

 

If none of your lights "bounce" along with the gauge then it's just the gauge itself going on the fritz.