Rechargeable Battery Internal Resistance Tester

With the rapid development of cell market, especially the market of Li-cell, manufacturers of cells have encounter many commercial opportunity and meanwhile has many problems to solve. The problems including single test method, the lower automation degree, inaccurate test of precision, and unstable performance hinder the development of cell in our country. The measuring instruments of internal battery ohmic discussed in this dissertation is developed under the background and is also the branch product of cell complex test instrument of our company.In recent decade, internal battery ohmic measurement has become a heated topic of cell users and cell manufactures and it also becomes a hot research topic to measure and predict the performance of cell by inner resistance test. However, internal battery ohmic contains complex and alternant components and cannot be detected by common ways. The common adopted ways such as DC internal battery ohmic measurement, AC voltage drop internal battery ohmic measurement and inductance measurement don't have a standard model and have obvious disadvantages and limited test range. And even the same measuring method has discrepancies in design and implementation. Given the disadvantages, the internal battery ohmic measurement is developed.Internal battery ohmic measurement system discussed in this dissertation is designed, referring to the international standard AC measurement and the requests of customers. This dissertation mainly introduces the system design and implementation of the measuring instruments of internal battery ohmic, and elaborates on the structure, the operational principle and the performance of system. It emphasizes the hardware and software design of system and some anti-interference methods. Meanwhile, it does some effective improvements aiming to the disadvantages mentioned above. Based on the feedback of customers, the model of machine has satisfied the civil market. The demands of cell manufacturers on inner resistance testing have further expanded the market.