Effect of Charging Current Variation on Internal Resistance in Lithium-Ion Batteries

Abstract

Internal resistance of a battery is affected by the amount of charging current and how many charge cycles are carried out. The value of internal resistance is also related to the State of Health (SoH) of the battery. The smaller value of internal resistance indicates a higher SoH of the battery. This paper presents a comparison of internal resistance due to variation of charging current. The current values are 500 mA, 1000 mA, and 3000 mA. Lithium-ion 18650 batteries which have capacity 1200 mAh are charged by these current values. Three batteries are used using three scenarios, namely the 500 mA for scenario 1 using the Liitokala-Lii500 charger, 1000 mA for scenario 2 using the Liitokala-Lii500 charger, and the 3000 mA for scenario 3 using the XL4016 constant current (CC) constant voltage (CV) charger. Every battery is charged 20 times. Internal resistance of each battery is measured using YAOREA YR1030 module during experimental work. The data experiments indicate that variation of current of 500 mA for scenario 1, internal resistance is increased by 1 mΩ. Scenario 2, 1000 mA, internal resistance will extend by 1.4 mΩ. Scenario 3 which uses 3000 mA, gives the highest internal resistance alteration by 2.1 mΩ. It can be concluded that the greater values of charging current will affect a higher value of internal resistance.