You may also want to check the AC clutch fan relay in the fusebox under the hood. With AC use, a faulty one can drain your battery. If it is made by Omron, change it out to this other brand (Misuva or something like that, made in Vietnam). My daughter did it for me last weekend, and actually I realized it fixed a problem I wasn't quite sure I had because earlier this month, I used the AC and it wasn't very cold at all. After swapping out the relay, it is super cold, so the relay was failing in some way, and I thank fellow member Northof49 here for pointing it out and probably saving me a dead battery down the road.