Syseng68k, #911
Yes, wind energy systems.
There's stiil the problem of >1 cell shorting to case, but I guess
that scenario could be covered by fusable links between the cells, rather than the existing copper straps.
This can be mitigated by ensuring the system can detect and isolate the first fault, and prevent further fault.
However, my point would still be that if the cells are properly managed and run within data sheet limits, the problem won't arise in the first place.
The high number of failing batteries could indicate that either the cells are having quality issues, or the cells are operating outside limits.
I'm not sure that number of thermal runaways would be zero, even if the cells are perfect and running under perfect conditions.
Each cell has many square meter of foil, in multiple layers separated with a tin layer of metal oxide.
An imperfection in the metal oxide layer could result in a short.
If the cell is large (or multiple cells are connected in parallel), then the amount of energy that can be dissipated in a fault area is higher, and may reach the combustion/runaway temperature.
Measures sufficient for small cells, might be insufficient for large cells.