Originally Posted by JFNM
I believe the question is as follows, perhaps it is me that is mis-understanding.
No... you are not misunderstanding. It was me that made the blunder. The difference between AH@120 volts and AH@12 volts is crucial, and I had simply ignored/omitted it.
If I had followed my own advice about paying attention to units, I would have caught the error. My bad.