After parking a while my car will not start

I have to jump start it. I replaced the alternator yesterday but it did the same thing today.I had taken it to Autozone and they said that the alternator was only giving enough charge to drive the car but was not charging the battery, so I replaced the alternator and today went to start it gave me the same problem and I had to jump start the car and only then it started. The watch resets to nothing, the ac will not turn on until I jump start the car.