SAE AIR6897

This AIR provides basic background information and guidance for design and development of BMS architectures to be used in RLBs for aerospace applications. This guidance applies to batteries that are considered “installed” equipment and are intended to be part of the original or supplemental type certification or military airframe qualification. Unlike traditional aerospace batteries with aqueous-based electrolyte (lead-acid, nickel-cadmium, and nickel-metal hydride), rechargeable lithium batteries (RLBs) must incorporate a battery management system (BMS) to achieve an acceptable degree of reliability and safety as required for aerospace applications. The primary function of the BMS is to monitor the state of the cells and protect them from harmful conditions such as overvoltage, undervoltage, overcurrent, and overtemperature. Other typical functions of the BMS include cell balancing, state of charge estimation, state of health estimation, and built-in test. Optional functions that can be part of the BMS include prognostics for end of life, external communication, and data logging. The performance and reliability of the BMS is critical to successful adoption of RLBs for aerospace applications. However, at present, there are no documents that provide recommended practices or standardized requirements for the design and verification of BMS functionality in aerospace RLBs.