Battery Management System and its Applications

6 Test Results and Analysis

This chapter provides the characteristic test and degradation test results of the LiFePO₄ and Li(NiCoMn)O₂ power batteries widely used in electric vehicles and their contrasting analysis to provide a reference for BMS research and development.

6.1 Characteristic Test Results and Their Analysis

6.1.1 Actual Test Arrangement

After the sample of a new battery is obtained, the BMS developers are required to make a characteristic test for the battery sample to obtain enough parameters. The comparatively complete characteristic tests are given in Table 6.1. The test items mainly include the battery capacity, the equilibrium potential curve, and the equivalent internal resistance curve. In order to obtain the characteristics of a certain type of battery at different temperatures, a –10 to 40°C test ambient temperature range was selected and a set of data was collected every 10°C. In fact, the temperature range of the characteristic test should basically cover the actual operating temperature range of the battery. The temperature range from –10 to 40°C mentioned in this section is only applicable to the specific application of a certain battery type. In the actual work, the test temperature range can be selected according to different practical applications. The specific steps of the characteristic test have been discussed in detailed in Chapter 5 and will not be repeated in this chapter, which mainly provides the characteristics test results and their ...