Design a battery management system (BMS) with an automatic cut off system on LFP (LiFePO4) battery type for powerbank application

Abstract

A battery is a cell device that can store energy and be converted into a constant voltage. Overcharging and over-discharging conditions on the battery are often a problem. This research designed a Battery Management System (BMS) to monitor battery performance with an automatic Cut Off system. The prototype system uses a voltage divider circuit in the voltage measurement process, one channel relay as the process of cutting off the electric current and Arduino UNO microcontroller as a data processor. Testing on five cell LiFePO4 (LFP) 3.2 volt battery with 1200 mAh capacity using the charging and discharging method in measuring the battery voltage. The results of measuring the voltage in the charging process take 2 hours 25 minutes to reach a voltage of 3.26 V obtained an average error value of each cell measurement of 0.44%. While the discharging process, to reach the voltage of 2.00 V, required an emptying time of 7 hours 15 minutes for output without step-up and 2 hours 46 minutes for the output with step-up obtained an average measurement error value of each cell 1.11% and 1.39%.