Abstract: To address low monitoring accuracy and delayed control response in lithium battery energy storage during renewable power generation, a system based on high-precision digital acquisition is developed. Using a 16-bit high-speed multi-channel ADC with signal conditioning, digital filtering, and dynamic calibration, it achieves ≤2 mV voltage error, ≤0.1% current accuracy, ≤0.1 ℃ temperature accuracy, and a 200 ms acquisition cycle. Six-month application in a 10 MW wind–PV–storage plant shows improved efficiency and reliability, meeting industry standards.