Minimizing the state of health degradation of Li-ion batteries onboard low earth orbit satellites

Satellites have a tangible impact on our daily lives; they provide us with many services like communication, global positioning, etc. Satellite batteries are expected to deliver the power demand at any time during the period of an eclipse, or when the power received from the onboard solar panels is not sufficient. The focus of this research is to develop an energy management mathematical model that reduces the state of health degradation of a battery in a low earth orbit (LEO) satellite. This improves the battery lifetime; thus, increasing the length of time a LEO satellite can stay in service. The developed model for a LEO satellite is solved separately for meeting three different objectives. In addition to the model, a heuristic approach is developed, and the results are compared to those obtained from the above-mentioned model. In this endeavor, data are collected for an existing LEO satellite, Nayif-1, in order to analyze the current battery behavior in space and to compare it with the developed model and heuristics. Sensitivity analysis is conducted to observe the effects of altering different parameters of the model. The results presented in this research show that minimizing the sum of products of the battery state switches and the battery current yields the best results by enhancing the lifetime of the battery by 8 days and providing 122 more cycles than that observed in the data from Nayif-1, assuming that the DOD of the battery remains constant throughout all orbits.