It seems lithium ion batteries are everywhere these days: digital cameras, hand held ham radios, cell phones, etc.  Recent fires on aircraft have cause more concern about the safety of these batteries.  Under normal circumstances, lithium battery fires seem "rare".  But in confined spaces, such as aircraft in flight, any fire, regardless of the source, can be deadly.  Lithium battery fires are different than most fires we might encounter.

There is a free online course for the general public at http://shop.avitas.com/resources/LithiumBatteryFiresGeneralPublic/story.html

All hams are required to operate their stations in a safe and prudent manner.  As technology changes (i.e. newer battery types), we must act responsibly and learn about the fire safety of these batteries in our radios.

Best wishes to all