Scientific and technological innovation serve as the wellspring of human social progress and the cornerstone for the evolution of China's renewable energy technology and equipment from weakness to a strong position of global leadership. Battery energy storage functions as a "super stabilizer" for the secure renewable energy operation. Testing instruments, consequently, are the key national assets across the entire lifecycle—including research and development, production, manufacturing, and deployment—of battery energy storage and the wider renewable energy systems. This article presents a case study on battery testing technology and instruments to systematically review the evolutionary path of China's battery testing instruments from import dependency to independent technological innovation. Specifically, create an integrated testing methodology of "fast and accurate excitation-intelligent modeling and estimation" for high-voltage batteries, which fills the gap in theoretical methods in the field of battery testing; Promote the localization of high-voltage and high-power testing instruments as well as create many international top technical metrices, such as charge-discharge conversion time < 3 ms, Energy conversion efficiency 95%, which seizes the commanding heights of science and technology in the field of international battery testing. Finally, this article analyzes the coordinated development relationship between the progress of battery testing technology and China's renewable energy industry. It summarizes practical experiences and lessons learned through the independent development of testing instruments: Chinese researchers defy international technological blockades, courageously undertake formidable tasks with resolve, and adhere firmly to confidence in academia and development path. Through close alignment with key national strategies and market demand, they overcome tough challenges, integrate industry, academia, and research, accelerate the deployment of innovative technologies to the industrial front line, and achieve self-reliance and strength of battery energy storage testing instruments in science and technology.