acid is necessary to create current flow to make a battery.
Not exactly. An electrolyte is necessary to allow current flow to make a battery (and create galvanic corrosion). The only requirement of an a electrolyte is that it be a conducting fluid. Bases work as well as acids, and you can construct neutral electrolytes.
Sea water is a basic electrolyte with a PH around 8. Distilled water and sodium chloride would yield an electrolytic solution with a neutral ph (neither acid nor base)--but it would support galvanic corrosion like no tomorrow!