Nissan Repair: Nissan Sentra Bad battery cell, nissan sentra, auto locks

Question
I have an 08 Nissan Sentra with 18000 miles. I have owned the car for aboout 17 months. Last month my battery died and I jumped my car and everything was fine. About fifteen days later the same thing happened to me. I figured I must have left some lights on or something. I jumped the car and everything was fine again. A few weeks go by and my car is dead again. This time I take it to the dealership and they tell me I have a bad battery and they replace it. A week later I turn my car off, run into my house to grab an item for two minutes tops. I come outside and  nothing electronic works at all. My auto locks won't even turn on. I take it back to the dealership and they tell me I have another bad battery and they replace it again. Are they totally missing something here??? They checked the alternator and the cranking system and said everything was good.

Answer
Carl,

I would go to Autozone or Checker and get a free electrical inspection as a backup plan.  It could be that they have not found the problem if does not show up when they check it.  It could be the alternator or even there could be a bad batch of batteries.