787 Batteries and Chargers - Part 1

[RR_NDB]

An inflight fire inside FWD EE bay was going to happen

Hi,

A simple analysis (equivalent circuit) reveal ANA at TAK case was benign because battery (very probably) destructed an aircraft cable and was (due heat in cell # 3 plus terminal region) destroyed internally (opening) preventing it to continue the thermal runaway like happened in BOS.

The (probable) short circuit was:



Battery was bound to caught fire (like in BOS) but:

1) A short to ground created generated a thousand Amps current to ground from cell # 3 plus terminal, region.

2) This huge current "opened" the circuit.

PS

There is one point in TAK different from BOS:

JAL APU battery probably was at maximum charge level or approaching it.

ANA MAIN battery certainly lost energy during the short circuit.

Question:

This could explain why a fire (external) didn´t happen in TAK? Lower charge after intense discharge?