[pdonis]

Read a bit further:

Chairman Hersman said that potential causes of the initiating short circuit currently being evaluated include battery charging, the design and construction of the battery, and the possibility of defects introduced during the manufacturing process.

They don't know the precise cause, but they have narrowed it down to a few possibilities.

[grecy]

Chairman Hersman said that potential causes of the initiating short circuit currently being evaluated include battery charging, the design and construction of the battery, and the possibility of defects introduced during the manufacturing process.

Paraphrase:

"The thing we built doesn't work properly, and we think it could be because of how it works, how we designed it, or how we built it".

Sounds like a useful assessment.

[HeyLaughingBoy]

Of course it's useful. It's just like debugging code: when the bug first surfaces, the cause can be anything in a large space. As you learn more of the characteristics of the bug, the problem space grows smaller until you eventually identify the root cause.

They've just learned what areas to focus on.

[maaku]

"how it works, how we designed it, or how we built it" is pretty much inclusive of every possibility and doesn't rule anything out. In other words, useless.

[pdonis]

The NTSB is not saying what you are claiming. They are only talking about those possibilities in reference to one specific failure mode: a short circuit in a single battery cell causing a fire that spreads through the entire battery. That rules out a lot.

[pdonis]

Um, the NTSB didn't build the battery. The quote I gave is from the NTSB chairman, not from Boeing. She was talking about the current state of an ongoing investigation, which has already narrowed down the possibilties greatly.