The battery internal resistance tester adopts color resistance touch screen. The instrument is operated by finger or touch pen, which is flexible and convenient. It is a digital storage multi-function portable tester which can quickly and accurately measure the operating state parameters of batteries. The instrument can detect the voltage and internal resistance of single battery on-line, store and process the detected data, alarm the battery fault, and accurately and effectively distinguish the good condition of single battery. The instrument saves, queries, deletes and exports the test data. The upper computer software automatically generates the battery test report by analyzing and displaying the test data through various charts.