Boeing 787 Dreamliner – A Case of Battery
The FAA recently grounded the Boeing 787 Dreamliner due to safety concerns surrounding the innovative aircraft’s lithium battery. Lithium battery technology is complex and hard for the layman to understand. Overheated batteries that cause smoke and fire alarms are all too easy to grasp.
The lithium ion battery aboard the Dreamliner is the large, muscular cousin of the regular lithium batteries found in consumer gadgets like cell phones. It packs a lot of bang for the buck, and its light weight is very attractive for aerospace applications, where extra pounds add to fuel burn.
Karl Denninger has written an intriguing analysis of the issue (marktet-ticker.org). Lithium ion batteries have extra vulnerabilities in cases of failure:
Part of the problem is that the reaction in the battery itself (like all batteries) produces heat, but in addition the cathode in many of these produce oxygen. Unfortunately chemical reactions proceed faster the hotter things get, and as a result a thermal runaway is possible, especially if there is a short-circuit that cannot be automatically interrupted before the battery gets hot enough to thermally run away. …
The fact that overcharging is not implicated in at least one of these incidents leads to some uncomfortable places, with the most-serious being a potential problem with the assembly of the battery itself (that is, an internal flaw that produced a short circuit inside the case.) This has occurred with laptop and similar batteries in the past and is extremely dangerous because the usual protective circuits are of course not effective. If this is proved to be the case here then Boeing’s supplier of that battery likely has a major problem with future orders, but more importantly Boeing may have an unsolveable problem with the use of these batteries, because it is essentially impossible to insure that no defects in the battery pack’s manufacturing will ever occur
Production flaws involving lithium batteries have already occurred with laptop computers and the Chevy Volt. But a large commercial jetliner is one of the most expensive capital assets on the planet, and the Dreamliner’s battery issue is potentially a huge business risk for Boeing.
There are some other interesting twists to this story. A number of governments restrict the transport of lithium batteries by passengers on commercial aircraft or as freight. On the political front, the affair raises more questions on the efficacy of government regulation. The Dreamliner had to be deemed airworthy by the FAA before it could go into commercial production, and the question naturally arises: “What did they miss and how did they miss it?” The speculation appears to be in full swing (Flight Aware).
Photo courtesy of Tennen-Gas via Wikipedia