Hi there,
You could have a faulty battery, get it load tested to make sure, also have a current draw test done, place am Amp meter between the battery pos and the cable, with key off and doors closed check current draw, if above around .25Amps you may have a relay or switch leaking voltage, pull each fuse and fusible link one at a time to see if this will isolate the faulty circuit, start here.
Mark (mhpautos)