Clearly I'm no expert either. And you are correct about the vent. There is a link a few pages earlier in this thread to "Intelligent alternator control IGR used on 2007 models and onwards (1).pdf" that *clearly* says all cars with same have an AGM battery. The factory battery from my car (I still have it) sloshes around, and so is this a regular lead-acid battery? Huh, that would seem to contradict info in the aforementioned doc on alternator control.
Confused (just in a thirst-for-knowledge kind of way
)