Grading of Lithium Ion Battery Module for Public street lighting

Abstract

A module of lithium ion battery has been constructed to replace ion battery for public street lighting. The module was designed to deliver a power of minimum~120 Wh for running 10 Watt solar street llighting, with a solar panel of 80 Wp. The module consisted of 40 cylinder cells 18650 of LiFePO4. Before designing the module, all the cells have to be formatted, graded and sorted out, to obtain an optimum results. The charge-discharge testing and internal resistance were measured to every single cell using a battery analyzer. The cells grading,sorting and grouping were consecutively done to obtain an optimum LIB module. The results showed each cylinder cell delivering discharge capacity, voltage and internal resistance of ~1.2-1.4 Ah, ~ 3.2-3.3 V, and 50-70 Ω, respectively. The cells were arranged into 4 serial and 10 parallel, to produce LIB module with the power of ~130-140 Wh, which is higher than expected.The LIB module made in Indonesia, with high local content can run the public street lighting and replace the conventional Lead Acid battery.