If you pour out all the acid from a battery and replace it with a new one, the battery will not function properly. The acid in a battery, typically sulfuric acid, plays a crucial role in the electrochemical reactions that generate electrical energy.
In a lead-acid battery, which is a common type of battery used in vehicles, the acid reacts with lead plates and lead dioxide plates to produce a chemical reaction that generates electricity. When the acid is removed and replaced, the necessary electrolyte for the chemical reaction is lost, rendering the battery inoperable.
Moreover, battery acid can be hazardous and corrosive, so it's important to handle it with care and follow proper safety procedures. If you need to replace the acid in a battery, it's recommended to consult a professional or refer to the manufacturer's guidelines for safe and appropriate procedures.