Design of a Battery Pack for a Solar Power System at the Farmers' Group Hut in Guo Village, Padang City

Abstract

The utilization of lithium-ion batteries to store electrical energy generated from sunlight presents an effective solution due to its efficiency and reliability in supplying power from a Solar Power System (PLTS) to a farmers' group hut in Guo village, Padang. Lithium-ion batteries were selected as the storage medium because of their efficiency, longer lifespan, and environmentally friendly characteristics. However, these batteries require a meticulous protection management system to prevent damage from overcharging or over-discharging and to ensure that the voltage of each cell is balanced during the charging process. This research was conducted by designing and testing a lithium-ion battery pack composed of 48 INR 18650 cells. The system is integrated with a 3S 40A Battery Management System (BMS) to regulate the charging and discharging processes, along with an active balancer to equalize the battery cell voltages. Based on calculations, the required battery capacity was 96.42 Ah, which led to the assembly of a battery pack with a total capacity of 102.4 Ah. The results of the protection system testing indicate that the protection management system functions correctly. The BMS successfully cut off the charging current when the voltage reached 12.5V and stopped power delivery to the load when the voltage dropped to 7.9V, effectively preventing overcharge and over-discharge. Furthermore, the active balancer successfully equalized the voltage of each parallel cell group to 4.0V, ensuring optimal and uniform charging. This protection management system is expected to maintain the battery's health and extend its operational lifespan.