Lexus would die like having bad alternator or battery. After recharge, Lexus would start only to stop short time later extending to half an hour. Local shops insisted on replacing main computer @ $1800.00. Finally, charged car and drove it home for private T/S'g.
Discovered problem was bad connection of three wire feedback connector into alternator itself. Once removing, cleaning with alcohol, charging was consistent and continues running even now months later. Hope this saves someone headaches as was unable to discover this fix on any forum.