How long does it take the battery to die? It sounds like you have a parasitic draw on the battery. Charge the battery first. Then disconnect the negative battery cable from the battery and install a draw tester inline on the negative battery cable. One end of the tester connects to the Negative battery post, and the other end connects to the negative battery cable. Close the tester so it is part of the battery cable first. Drive the vehicle and use EVERY accessory during the drive (radio, wipers, headlamps, flashers, defroster, A/C, etc.). Park the vehicle and open the hood, then hook up a DVOM with the AMP setting (every meter is different, but use the setting between that says "A" not "mA") selected. Wait at least 3-5 minutes before doing the next step so that all the accessories and modules in the car have a chance to go to sleep (and make sure all the door are closed so the dome light doesn't give you a false reading). Then open up the Draw Tester and see what the meter reads. If the reading is high, start pulling fuses one at a time (you may have to have someone in the vehicle to do this as I don't remember if you can reach the fuse box from outside without opening the door) until the reading drops within the acceptable range. You then know what circuit to check for loads causing the draw. You will have to check on the battery itself or get specs from a service book or the battery manufacturer's website to know how much of a mAh (mili-amp hour) draw the battery is designed for. If you are unsure about how to do any of this, seek help from a qualified professional in your area.