Okay, just got home after a 5 month deployment on the USS John C Stennis. Right before I left, I swapped heads/gaskets due to a cracked head. After I left, my wife Dustie tried driving home Fresno to visit family and the car died on her about halfway there. Her family came and got her and the car and towed them to Fresno where they discovered a bad alternator and some blown fuses. The alternator was replaced as well as the fuses and the car seemed to run fine. After a few days of driving, the car died on her again. Once agian they towed the car to her families house in Fresno and there is sat till a couple weeks ago when they were nice enough to tow it down to San Diego so i coudl work on it when I got home. My wife has been driving it around on short trips since the car has been here without a problem until today when it wouldn't start again due to the battery being dead. Jump started the car and it ran fine after it started and we drove it home. When we gotit home, I broke out my volt meter to take some reading to check the alternator which is what I suspected was the problem. But it was putting out 15V at idle(seems a little high, but it was trying to charge a dead battery) Ran the KOEO and KOER tests using the code reader I have and except for the EGR codes due to EGR being unhooked currently, it passed the tests with no problems. Had to jump start the car to do the tests though. Luckily I have a spare battery in my garage. Put the spare battery in he trunk and went to do some shopping. Didn't have any problems for the rest of the day. Bought a cheap battery charger while I was out and am now charging the battery. I'm just stumped as to why the battery won't keep it's charge while driving even though the alternator seems to be doing it's job. Only other electrical load on the motor that wasn't normal is I had a bypass on the pusher fan hooked up so the fan ran anytime the key was turned on. Any help would be appreciated.