The fully automatic vacuum acid filling system is used in lead-acid battery assembly to inject electrolyte accurately under vacuum. This allows electrolyte to penetrate the plate and separator structure evenly, improving battery performance and product consistency. The system integrates filling volume control, automatic container loading, vacuum control, water cooling, and inspection functions for real-time monitoring and precise filling quality. Battery scanning, weight inspection, automatic rejection, and data logging can be combined to reduce process variation and support production traceability.