Catylistic

Hey guys! Just replaced my alternator and voltage regulator on my 79 corolla wagon with a 2tc. It charges the battery but ive been having to leave it for about 2 days for when i go to school. I come back and the battery is dead. Eversince i replaced the alt and reg the chg light on the dash turns on when i turn the car off. I'm guessing the light is draining the battery. Anyone have any ideas on why this is?