Go to where you bought your battery and alternator and have the charging system tested, should be between 13.6 and 14,4 volts. Then you will need to do a test to verify where the draw is coming from, cheap rebuilt alternators are prone for this.
By the way what CCA rating is on your new battery.
Also if the battery dies, you "MUST" recharge it, don't just figure your alternator will recharge it cause it takes days of driving to even get close.

 

While you have that meter handy, put one probe in the center of the battery connector, and one on the same battery cable lug. Switch on the head lights. You want that "voltage drop" to be as low as possible. If the connector is dirty, corroded, you can build up a lot of resistance and even a new alternator won't charge a new battery. A clean connector on the outside may have gunk inside. You can also move one of the probes down the cable to the next junction point, looking for increased voltage drop across connectors and wire joints, even terminals in the under the hood fuse box. Increased resistance shows up as more voltage drop under a constant load (like head lights). Good readings are very small fractions of a volt.

 

Yes, I did recharge the battery with a battery charger. The battery is about a month old and is an optima yellow top. The alt is a cheapo rebuild (not really cheap, more like the halfway model) but did test out at 13.9 volts yesterday at autozone. It is only a week old, and I know they can be bad out of the box. This problem happened the first time prior to the new alt. It is not every time, and I already checked the cables for a voltage drop. I am failry certain there is something that is intermittently drawing power. I was just wondering if anyone on this forum has experienced this problem, and what was the solution, because there is a lot of things that have the potential to draw current...

 

Load test the battery with a carbon pile tester.

 

Problem Found! It was the rear subwoofer amp! Even though I dod not have the factory stereo, it still got power all time. It is suppose to get a signal from the radio to turn on. Mine was intermittently turning on and killing the battery with no signal.

 

So it was getting a stray "Turn on" signal. Good to know. Wonder whaty kind of signal was doing that.

 

I think the amp was wonky, the signal wire for the amp was not hooked to anything. However the amp was still getting power, so it would just turn on for no reason at all. No more, it now resides in the trash can.

 

Probably the best place for it.