787 battery question
 

When the 787s were grounded there had been sufficient "fires" in the small fleet to cause concern. The solution that was widely reported was to put a box around the battery so that in the event it did catch fire it would be contained.

Since the planes were released back into service, having had their box fitted, I haven't heard of a single fire (related to the battery). I find it difficult to believe that simply putting the battery in a box stopped the fires so what else happened? What did I miss?

While the steel box got all the attention, they also redesigned the battery. Basically they increased the space between cells and added more insulation such that, if a cell faulted and started to overheat it wouldn't propagate to the surrounding cells. There were other changes as part of the fix but I don't recall details.
Since return to service, there has been one report of a battery problem where a single cell overheated, but it didn't propagate.

Thank you, tdracer. I find it especially reassuring that there has been one case of an overheating cell recorded, because it's in the nature of the technology that this will happen, and evidently the redesign worked.

This matters to me, because Air New Zealand are pretty much committed to the 787, and they're my preferred airline, and I had been a bit concerned about the battery problem.

Exactly my sentiments Flightless. Thanks tdracer.