In my, admittedly anecdotal opinion, this buildup of sulfuric acid salts is the result of electrolyte leakage around the terminal. I start to notice it on older batteries that are nearing the end of their service life. I am "guessing" that the leakage is caused by pressure buildup inside the battery as the electrolyte "bubbles", when the battery is experiencing a recharge. I generally start thinking about replacing any battery when I see this, or a drop in the electrolyte level in any of the cells.
And yup, electron flow is from negative to positive - I learned that in college physics too. Electrons ARE negatively charged, aren't they? Makes sense they'd flow to the positive side. (Not that anyone cares.)
- Jack
