That white stuff may be battery acid that leached out around the positive post (very common). This causes sulfates with the lead and slowly eats away the lead terminals. You can check it very easily, take 1 tablespoon full of baking soda and two tablespoons of water and mix together into a slurry, apply some to the "white" area. If it foams up it is acid. The baking soda will neutralize it so this is a good thing. Rinse the batery off with clean water