Applied ohmic battery testing in a global mobile telecommunications operator: A multi-year study

Abstract

Since the year of 2006, China Mobile had carried out field tests on hundreds of strings of batteries to verify how conductance/impedance tests could indicate the battery's health condition and its capacity, results of which has been presented in 2007 Intelec paper. With the conclusions drawn from the validation filed tests, China Mobile started to apply the ohmic testing technology in the practice of battery maintenance work, including using conductance testing on approval inspection before installation of new batteries, which has greatly improved working efficiency and more importantly, helping improving the stability of the quality of the batteries delivered, and using conductance testing in regular battery maintenance work greatly help to screen out defective batteries and to decrease failing cases compared with before. The simple fast testing method has proved to be most practical tool to be used for the patrol tests of batteries in thousands of base stations right after the snow storm calamity happened in China in the Spring of 2008 and the earthquake happened in May in Sichuan Province. This paper will then further focus on the new database software's development and its applications in Zhejiang province. With more and more ohmic testing data and load testing results of the batteries accumulated and uploaded in to the database software platform, clearer and more exact relationship between ohmic testing value and load tests data are obtained day after day. With the abundance field tests data, BHItrade (Battery Health Indextrade) was developed, which is a key part of the database software system. BHI includes 34 different parameters that have influence on the battery's condition. It is designed and developed to get relatively reliable information of the battery's current health condition with fewer cumbersome load tests. With this same database software system, a complete battery profile is set up, and health condition of each individual battery could be assessed, anytime and anywhere. Data continues accumulating from regular maintenance work and uploaded into the software system, and new study and analysis of battery condition progresses. With more understanding of ohmic testing and more confidence in the technology Chinese telecom operators will need to perform fewer discharge tests in the future, saving time and money.