Battery light flashes while driving
 

Hello, i am hoping to het some information about this problem i have. So about 4 months ago i replaced my alternaton because my old one gave out. I went out of town agter that and didnt drive it at all after that until about a week ago May 19 2017.
when i drove it, i notice that the battery light, the ABS light and the battery light came on while i was driving. I took my car to auto zone to have my battery and alternator checked and they all passed. Shortly after that i took my alternator out took it to auto zone to have it checked by its self and it passed. What could my problem be?