Lyman:
Where I have wanted to go is to Thermal. From your background, would you have
in mind discrete heat signatures relative to Chemical decomposition as opposed
to resistance generated heat events?
It really isn't that complicated, starting from the premise that the cell will
work as advertised if not abused. I'm not a chemist and am quite happy to let
Yuasa deal with that and overall physical construction.
The cell data sheet specifies a maximum temperature, which if exceeded may lead
to thermal runaway. It's the job of the bms to limit the temperature based on the
data sheet values, with a margin of safety. Ie: if the cell is rated at 65C, then
the bms must have a hard limit below this, say 60C. For whatever reason, the
cells should be disconnected from charge or load if that limit is exceeded. The
same applies to min and max cell voltage monitoring, which did appear to work,
judging by the number of batteries that were swapped out due to excessive
discharge...