Lithium Battery Health and Capacity Estimation Techniques Using Embedded Electronics
This report details work at Sandia National Laboratories in development of a lithium-ion battery management system (BMS) designed to detect the state of charge (SOC) and state of health (SOH) of a battery. The goal was to create a BMS that provides advanced SOH information without adding complexity to the hardware already required for monitoring battery safety. The hardware is designed to have low processor requirements and relatively low cost components, while offering several high end battery management options like communication, automatic SOC detection, capacity tracking, and multiple SOH characteristics. The methods for detecting capacity include coulomb counting and resistance-compensated voltage calculations. Several methods for assessing the SOH were also considered, including deviations in capacity using coulomb counting, DC resistance analysis, and time domain resistance analysis.