I am stumped witht this, 1 day my car dies so i go to try and get the battery charged and then i was told the battery was bad so i bought a new 1. Drove on it for about 3 weeks then it died so i replaced the alternator and drove on that for 2 weeks. Now the car slowly dies out when driving. Could this be something wrong with the grounding or no charging between the 2?

 

i would definitely check grounding and the charging system! check all the wires to the alternator and even to the battery both positive and negative. hopefully you dont have a short hope this helps.

 

I dealt with the same thing and it ended up being that my passenger power seat was stuck in the 'on' position so it was constantly draining the battery

 

Bring it to your local Auto store, they will diagnose it if you have not done so.