Probably doesn't apply directly to aircraft, but interesting nonetheless.
Our Lithium-ion Batteries journal covers four key subjects that
demonstrate how UL is working to enhance the safety of lithium-ion
batteries. Fault Tree Analysis is the foundation of how we approach
lithium-ion battery safety — by identifying and understanding the root
causes of failures. We found that one of the leading causes of failure is
an internal short circuit (ISC), so we developed a simple and repeatable
way to induce ISCs. The Indentation Induced ISC test enables us to
study battery behaviors when an ISC occurs. This and related research
has given us insights that we’ve used to update existing standards and
create new ones to address the most recent applications of lithiumion batteries.
Finally, a new area of potential concern, Aging Effects, is
a significant area we are focusing on, given the trend toward longer
battery life and second-use applications for lithium-ion batteries.
http://www.ul.com/global/documents/n...al_Issue_2.pdf