[SkyMG37x]

The battery may test out fine, but what I've learned about the charging system on this car may be related to why the battery gets drained.

There's a current sensor module between the negative terminal of the battery and the ground - it's part of the Variable Voltage Control System that's mentioned in the owner's manual and detailed in the service manual. The purpose of the current sensor is to determine the amount of current draw and control the voltage generated by the generator. So if your battery is not charging properly then it's quite possible that the current sensor could be the culprit and not properly controlling the generator output. The dealer really needs to check the entire electrical system especially the current sensor module. I read at least one person on the forum had a problem with that.