if you disconnect the battery with the car running and the car stops running the problem can be isolated to the voltage regulator or the alternator(generator).Replace the voltage regulator first (it is inexpensive). If it does not remidy the problem the alternator is likley in need of a rebuild. If the car runs the same with the battery disconnected as it did with the battery connected then you are likely to have a power leak. You can check for the power leak with a voltmeter or a bulb as described by Bob...Have the local fire company on stand by and put on an asbestos suit just incase Don is right..good luck