posts 820-824.
individual relays on the 8 cells would not work The real problem in thermal -runaway, is that each "cell" is, in fact a BATTERY
Another member has already pointed this out on one of the numerous therads running.
A "cell" consists of several small cells in PARALLELL this is the only way to achieve the design objectives of discharge-rate/overall capacity/fault-limitation.
I have already suggested, the way forward is to link each of these sub-cells to the "Cell" terminal with a fusible link. If you look at the photos, you will see the terminal post is rivited onto the top of the cell-casing....I'd suggest that Pos. and Neg, busbars go down the stack and the individual sub-cells are parallelled to them. so, fusible links-each cell to busbar....fusible link of the necessarily higher order , to connect the internal busbar to it's terminal.
Cheap, effective AND EVERY SINGLE CELL HAS PROTECTION FROM OVERHEAT
Irrespective of wether it's caused by cell-fault, overcurrent, overcharge or over-discharge.
Assuming Boeing refuse to lose face and ditch the technology altogether, this would majorly address the safety-issue....the charger-unit and the connection direct to a "dirty" bus (OK, via a contactor/relay) are something else.
A failsafe strategy as outlined above would be cheap and easy to integrate and be very cost-effective.
Boeing/Thales can have the benefit of my "expertise" for free!!!!
No warranty given or implied. (like the existing batteries, then ?)