Recharged, Boeing’s Dreamliner gets cleared for takeoff

<quote>

The new, improved battery system's design has been altered to prevent the sort of fault that led to the Boston fire and the failure of a battery on an All Nippon Airways 787 in January. There is added insulation between each cell to prevent a short-circuit within the lithium-ion cells from cascading to others.

Even if the battery does fail and overheat, Boeing officials said, its new sealed steel enclosure system, with cooling and venting, will prevent a fire and contain the problem to the battery itself, protecting the rest of the aircraft. As part of testing, propane was used to create a small explosion inside the enclosure, which was successfully kept contained within it. Boeing claims that the enclosure will not only isolate a possible battery failure from the rest of the aircraft's components, but that passengers won't even notice if a failure occurs.

There are some unanswered questions that remain. Boeing was never able to replicate the failure that caused the Japan Air Lines 787 to catch fire in its tests of the old design. And considering that the original reason Boeing selected lithium-ion batteries for the 787 was their relatively low weight, the additional provisions would seem to cancel out much of the benefit of the technology.

</quote>