I have not been able to see any signs of anything draining when the car is running or driving. I do take the keys out of the ignition when I park it in the garage, so would that still mean that the ignition may be draining anyway when there are no keys in it? We messed for hours one day with trying to find something that was left on, and found not one thing. We locked ourselves in the trunk, unscrewed the bulb in the glove box and under the hood, but still nothing was left on.
We live in Wisconsin, so the batteries I've bought were from a local Auto Parts store, not a discount retailer. (I learned my lesson years ago regarding WalMart batteries). These batteries had 770 or so CCA, as that's what's needed in 30 below weather, so those definitely aren't the cheapie batteries that could normally be bought. I don't know the brand name though off the top of my head, but do know that this stock# is their 2nd best they sell in the store - with top battery seemingly being for high-end sports cars or heavy-hauler trucks. Even still, the brand new/high-quality battery won't last longer than 1 night unless we disconnect it from the cables after we're done using it. How would we go about testing for where a drain is? Would I use a ohm-meter for that? If so, what kind of reading should it be giving me to tell me if that is the problem? Can the fuse panel or something else help us along with the diagnosis?