Issue 1: Crafting black powder (via alchemy), it puts all the crafted items in stacks of ten. You cannot stack it higher.
Issue 2: The crafted black powder, when in these stacks of 10, uses up the charges of all the Black Powder in the stacks. For instance, I have 10 charges and 10 black powder. The charge is consumed for the entire stack.
Issue 3: The stacks of black powder with the same number of charges automatically re-stack in containers. For instance, in my magic bag I have a stack of 9 black powder. If I separate all of those into individual portions of black powder and relog, they will re-stack themselves in that bag.