You should have the battery load tested to be sure it's not defective. Also have the alternator output checked to be sure it's properly charging the battery.
I have seen behavior in my '03 like you mentioned when my battery was near the end of its life. The battery charge was just marginal enough to drop overnight and lose my settings, even though it still had enough power to start and run in the morning. The tip was it turning over slower than normal -- it you car cranking healthily in the morning?
I have seen behavior in my '03 like you mentioned when my battery was near the end of its life. The battery charge was just marginal enough to drop overnight and lose my settings, even though it still had enough power to start and run in the morning. The tip was it turning over slower than normal -- it you car cranking healthily in the morning?