According to Jon-Don, baking soda can be used to clean up a battery acid spill. Applying baking soda to the spill location neutralizes the acid, which can then be cleaned up safely.
If the battery acid has dried on the spot, it may be necessary to add some water to moisten the spot before adding baking soda. The baking soda should stay on the spot for about an hour to ensure that the spill is completely neutralized. The baking soda forms a paste. Jon-Don warns that it is important to test all materials for colorfastness, follow label directions and never mix products unless specified in the label directions.