Brian Abraham:
...Photo of such in a car.
The photo seems a NiCd pack. You may see cells inside and one outside the pack at left.
The lead acid battery, when driven into thermal runaway, will fail in such a manner that the aircraft is not endangered.
These batteries gave us "Fault tolerance" and "Graceful degradation".
Essential characteristic of a good design.
In general we can say lead acid are less critical.
rudderrudderrat:
Letīs hope for the same in 787. The less damaging scenario.