787 Batteries and Chargers - Part 1

[Chris Scott]

Saptzae,

Thanks for your latest posts. For a layman like me, they seem to summarise the issues facing Boeing, Securaplane, Thales, and (perhaps) Yuasu very clearly; particularly your description of the cascade effect following the shorting of one cell during charging.

Could you just clarify the last sentence of this part of your penultimate post, please (my bold)?

“Shorting
It is not going to be a solid short from one moment to the next. The energy is just too great. Cell could not ever dissipate it's 200 - 300 Watt hours quietly. It would short, arc, burn out the short and do more damage along the way. There would be over pressure, relieve valves opening, electrolyte blown out. More shorting as separators fail by the heat. The whole cycle continues until energy is dissipated and some spot shortened can not be burned out.”

Also, do you think that a manganese (spinel) type of Li-ion battery would have been a safer choice than the cobalt type, and would its performance be adequate for the task? If so, could its retrofit be one of the options currently under consideration?