Car dies must be jumped

Car has done this 3 times 3 months ago 2 weeks ago and the other day, pull into parking spot battery is dead jumped it and drove and it died while driving got jump start and got it parked battery dead ago towed to shop charged battery the battery and alternator are chargin mechanic said no loose wires battery is fairly new radio installed 6 months ago they checked draw on it interminate problem we are lost I cant keep towing in how about start valve or could it be computer runs great any other time