investigators fail to find the root cause of the battery fires, the technology could be deemed insufficiently mature for onboard aviation. The safety circuit at the connector end of the battery is unable to stop a thermal runaway once in progress.Ĭourtesy of the National Transportation Safety Board, Investigative update of battery fire on Japan Airlines B-787, 7 January 2013. The charred remains of the failed B-787 main battery featuring 8 GS Yuasa LVP10 lithium-ion cells. Figure 2 illustrates the damaged main aircraft battery. For consumer product wanting optimal runtime, Li-cobalt works well, but large formats have additional challenges. Lithium Cobalt Oxide (Li-cobalt) is known to be less stable than other lithium-based systems. It is the same chemistry that triggered a major recall of computer and mobile phone batteries in 2006 when one-in-200,000 cells caused a breakdown.ĬT scans done on the failed main battery of the B-787 reveal a similar breakdown that prompted the 2006 recall: a damaged electrode in one of the eight Li-ion cells apparently caused an electrical short that triggered a thermal runaway with fire. When the Li-ion battery was selected in 2005, the choices were limited and what we know today, the picked Lithium Cobalt Oxide (LiCoC2) may not be the best technology for onboard aviation. Hybrid vehicles only switched to Li-ion around 2010 with more stable chemistries. The Boeing 787 is the first commercial aircraft to use Li-ion as its main battery, and there are risks associated with this. Li-ion requires fewer scheduled services than NiCd, which needs regular full discharges to remove memory, adjustment of electrolyte and cleaning corrosion buildup. Another reason for selecting Li-ion is low maintenance. The Dreamliner needs the extra capacity to run additional electrical systems, including hydraulic functions that have been electrified. The main battery is composed of eight GS Yuasa LVP10 cells and provides roughly twice the energy density compared to the traditional flooded nickel-cadmium (NiCd) that other aircraft use. Image courtesy of the National Transportation Safety Board, Investigative update of battery fire on Japan Airlines B-787, 7 January 2013.īoeing chose lithium-ion to store more capacity at the same weight. The fire was difficult to extinguish smoke and flames didn’t break with the dry chemical of a fire extinguisher and airport firefighters used liquid Halotron. The incident happened after arriving at the gates in Boston from a flight from Narita, Japan. The Federal Aviation Administration (FAA) grounded the entire fleet of B-787 as a result.įigure 1: Damage in aft electronics bay caused by a burning battery in a Boeing 787 More than a smoke event occurred, and one battery disintegrated in a thermal runaway with fire and the spewing of electrolyte that caused damage to the electronics bay (Figure 1). This contradicts Boeing’s estimate as part of certification that a smoke event involving the new Li-ion battery should only occur once in 10 million flight hours. After fewer than 100,000 flight hours, two main batteries in the Boeing 787 Dreamliner failed.
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