1996 Saab 900 s wont hold charge in the battery...?

[guiltyspark502]

So the other day, car was fine, this morning I went to work, the car started fine (though it was the first cold night ive had with the car @ 22 degrees), so I went to work, then I got done with work, went out to start it, turned over twice and didnt start (battery obviously dead), so I tried to jump it to no avail, then just roll started it. So whatever, drove another 60 miles, stopped back at work, tried to start the car again, battery was still dead! So I put another battery that was fully charged in it that I know is good, then drove it another 40 miles, and the car was dead again! (luckily I was smart enough to park on a hill again). So now Im getting frustrated, obviously the alternator is working (or the car wouldnt still have functioning lights/instruments not to mention the juice needed for fuel pumps/ injectors ect.) So any thoughts are appreciated, I currently know that the battery is good and the alternator is good. Tell me what you think....
And I forgot to say, no warning lights, no check engine, no battery lights, and checks all go Okay.

[tsjsaab]

Sounds like a parasitic drain. How long is the car parked before it will not start again? There is a TSB (technical service bulletin) for this car, concerning a trunk light that stays on, draining the battery. If it will not start even after sitting for a short amount of time, either the battery is bad, or there is a bad connection from the bat. to the car. Check the grounding wire first, corrosion is common at both ends. Then check the positive wire to the starter. Are you sure the starter is not the issue? You say it will not start with a jump, so it must be a bad connection, or a malfuntioning starter. Keep in mind, if it is a wiring issue, the alternator will think the battery is completely dead at all times. This will result in "full-fielding" the alternator which will steeply decrease the life of the alternator and may damage sensitive electronics.