The use of lithium-ion batteries has greatly expanded in the past decade, powering everything from Tesla cars to iPads, and the risk of fire is well-understood, experts said at a forum organized by the U.S. National Transportation Safety Board. 

  The fire in the battery compartment of a 787 parked on the ground in Boston in January, followed that same month by an in-flight battery malfunction over Japan, led to the grounding of the Dreamliner. 

 

While the final cause of those incidents is still under investigation, Boeing has been allowed by the U.S. Federal Aviation Administration to conduct tests of a redesigned battery unit, part of the plane's auxiliary power system.