Safety testing of lithium ion batteries for navy devices

Lithium ion battery technology is being introduced into power supplies used by our armed forces for a variety of applications. In many cases, the same cells and design parameters that support commercial battery packs are being used in military battery packs. This approach is expected to result in a major decrease in the total life cycle cost of the equipment these batteries support. On June 13, 1991, NAVSEA issued INST9310.1B1, which states that all lithium battery powered equipment must undergo safety evaluation and approval prior to fleet use. This safety program governs a process whereby approvals are issued for lithium batteries to be used in specific equipment on ground facilities, surface combatants, air combatants, and/or submarines. The Naval Ordnance Safety and Security Activity (NOSSA) manages the program. The chief technical advisors are Code 644 at NSWC Carderock Division and Code 609A at NSWC Crane Division. This paper describes three battery designs that incorporate lithium ion technology, and the results of battery safety tests conducted in accordance with navy requirements.     

Evaluation of built-in test

Built-in test (BIT) provides fault finding as a means to aid in system assembly, test, and maintenance. An investigation to evaluate BIT of a particular electronics board used in the in-flight entertainment system for Boeing 777s is described. We found BIT proved useful when failure occurrences were uniquely associated with the operating environment, situations which can result in no-fault found, or could-not duplicate (CND) failures upon test. We also observed cases where the BIT failed to observe failures, and in some cases pointed to the wrong cause of failure. These and other advantages and disadvantages of BIT implementation are discussed     

Continuing challenges in lithium battery development

In these days of emphasizing standardization, Acquisition Reform, Non-Developed Items (NDI) and Commercial-Off-The-Shelf (COTS) technologies, we are facing new challenges associated with these trends. Program managers are pressured to use a standard or COTS battery, while simultaneously, the new systems being developed have increasingly complex and demanding power requirements. Hardware must be developed with shorter schedules, and policies of Acquisition Reform limit the amount of control the government has over the development of a given item. In this paper, we review battery development efforts that have resulted in unexpected problems. Relevant data from both current and past test programs are presented. Recommendations are provided concerning how to best avoid duplication of effort, while ensuring that the final product will have the best chances of succeeding