2000 nisaan sentra, battery light and brake light pops on periodically, took it to dealership, they said all the reading was good on the battery and alternator, they just to change the battery cables did that still lights come on

Its a bad alternator, a bad diode, replace the alternator this will solve your problem, when these alternators go bad the dash lights come on,it sounds like it sometimes charges and other times not,the car was charging when they got it so they really couldnt find much,ive run into this alot, check the connection at the alternator and battery if connections are good then replace the alternator, good luck.