A single cell (blade) failure can be contained. A multi cell failure (hub) is hard to contain.
Thus am I most concerned about fixing the Primary cause and preventing the Secondary and Tertiary cascading failures.
@Lyman
As to Monitor.... Secureaplane has their patent
From #590
http://www.pprune.org/7685780-post590.html
It is one of those patents one gets to get a patent for making life harder for the competition to sue one. Well, and a little for marketing hype too. As to its merit, inflection, prediction, assumption is IMHO a demerit.
Edit: I do not believe that the patent, which was developed for Pb type cells, is applied here, other than in the marketing documentation.
As we see, it is not possible to control (manage) charging in an eight battery (cell) series.
It has been discussed many times. It is common practice for more than 100 years. It can be managed.
Rather, by what we see, all boils down to inadequate management, on all levels.
- Primarily, of the cells, so they short.
- Secondarily, of the cell short, leading to the conflagration
- That 100+ batteries got line replaced
The containment box worked pretty well!
For a serviceable cell to short circuit, internally, the separation Anode/Cathode must be breached. As far as I can determine, that means a break down of the separator, and/or, the presence of metallic Lithium dendrites, spanning the borders of the connectors at either end.
Concur, but we do not know which, less so why, and the evidence is all but destroyed after subjected to heat sufficient to melt aluminum.
Dendrites far and away are the more troublesome of the two, separator issues are related to diffusion of the Ions, dendrites are a mechanical connector....
Yes, Examining other serviceable cells from the fleet for deterioration is my best hope.
The hearings are open to the Public. Are you considering being present?
Interesting question. I wont be present, but will consider to make a submission.
@HighWind
Welcome!
Yes, two hall sensors would be good.
Yes, two pole contactor would be better.
A bistable contactor would be possible.
@syseng68k
Fusible links would not be practical. Cells should be insulated more reliably (heat resistantly) from the case (edit: and each other).