The "risk vs rewards" game is underway. NASA has most likely analyzed the risk vs rewards situation, and still allows very expensive satellites to be powered by lithium - as Ron says, so the risk must be very low - even with full exposure to cosmic rays.
The percentage of lithium failures on commercial flights may be equally low, but there are enough actual failures to raise safety concerns. This is especially problematic since the risk of any lithium fire and its toxicity onboard an airplane at altitude is multiplied by the close confinement and the possibility that the flight crew will be harmed by the smoke. This is said to be the only incident reported in Australia, but due to stories like this: http://www.ainonline.com/aviation-news/aviation-international-news/2012-02-0 1/battery-fires-keeping-li-ion-caged . there appears to be a push to ban all lithium batteries, even in cell phones - or at least to require "hot bags" which may cost more than the phone. How long before a terrorist rigs his iPhone to catch fire? A satellite goes down and NASA is out say $50 million but a 747 goes down and United is out $500 million. From: Teslaalset On every intercontinental flight there are hundreds of portable device Lithium Ion batteries of passengers... if it would be a structual effect every flight would be causing disasters, wouldn't?
