Investigators are looking into the causes of a fire that broke out in the aft electric equipment bay of a Japan Airlines Boeing 787 shortly after passengers deplaned at Boston’s Logan International Airport on Jan. 7.

The JAL 787, which was delivered to the airline on Dec. 20, had been on the ground for 25 min. when smoke was detected in the cabin. Boeing says it is “working with our customer” to understand the issue, but declines to discuss specifics. Reports elsewhere indicate the source was an exploding lithium-ion (Li-ion) battery, which provides power to start the auxiliary power unit (APU).

The incident is the latest in a series of electrical system-related issues to dog the 787 over recent weeks. Problems in a power distribution panel forced the diversion of a United Airlines 787 to Louis Armstrong New Orleans International Airport on Dec. 4, while subsequent electrical system-related issues have been reported by Qatar Airways and LAN Airlines.

The APU battery is one of two primary batteries in the 787, the other being the main battery in the forward electrical equipment bay. Both are Li-ion units provided by Japan-based battery manufacturer GS Yuasa, as part of the Thales-supplied electrical power conversion system. This marked the first commercial aviation application of Li-ion technology and was selected over contemporary nickel-cadmium because it provides 100% greater energy storage capacity and double the energy from the same sized unit.

Despite certification conditions set by the FAA in 2007 regarding the use of the technology, the unit’s manufacturer says battery management electronics “guarantees multiple levels of safety features.” In a statement made at the time of the contract award, GS Yuasa said the “prismatic sealed battery design is capable of withstanding extreme operating conditions far greater than those normally seen in commercial aircraft operation and requires absolutely no maintenance.”