Advanced Li-Ion Battery Balancing Solution Using Commercial Off-The-Shelf Components for MicroSatellites

Li-Ion batteries have become essential for space missions as secondary powersources due to their high performance and power density over the past twodecades. However, variations in cells’ characteristics of a battery pack can leadto reduced overall capacity over time. To address this issue, various battery balancingmethods have been developed to extend battery life. This article presentsa space-qualified passive battery balancer that utilizes commercial off-the-shelf (COTS) components. Its design is particularly suited for space applications,emphasizing low power consumption, high efficiency, and tolerating harsh spaceradiation environment. A battery pack incorporating the proposed passive cellbalancer has been successfully deployed in a microsatellite recently launched intolow Earth orbit (LEO). The satellite’s housekeeping data demonstrate the effectivenessof the balancer, maintaining cell voltages within specified limits up toone year after launch. Notably, the suggested balancer can reduce the state ofcharge (SOC) by 1% per orbit, contributing to enhanced battery longevity.