Lithium-ion cell data acquisition prototype of a personal mobility electric vehicle

Abstract

This article presents a prototype for the acquisition of voltage and temperature data from lithium ion cells (LIB) in a traction battery of an electric personal mobility vehicle (EPV), as well as the acquisition of data on its speed and acceleration, for diagnostic tool. All the signals are transmitted from the EPV and received wirelessly in a computer through the MODBUS TCP protocol, which enables a WIFI link between the EPV and the computer. The signals obtained from the acquisition prototype have been used to evaluate, on the one hand, its correct operation validating it using an “NI myDAQ” and, on the other hand, the variation in time of the measured quantities, in order to determine the behavior of the batteries in their discharge process. In relation to this point, the voltage variation among the cells has been obtained, reaching an value of 0.09V up to 20% of the traction battery charge and 1.10V below this percentage. Furthermore, it has been discovered that the voltage difference between cells 01 and 10 below 20% payload increases significantly, having an average of 0.17V within the normal range and 0.43V below the aforementioned percentage. This work makes it possible to identify the optimal operating conditions and preventive maintenance conditions for EPV batteries.