NTSB playing with high tech kit to find out what many suspected
anyway and still no info as to the cause of the problem, in public
at least.
My premise is still that there's basically nothing wrong with the
batteries, despite ntsb playing with them for many, many days, almost
obsessively. Makes one wonder what the real agenda is there.
Assuming that the batteries are ok, this leaves only a few possibilities.
1) Operational conditions far outside those expected, which may have
prompted software bugs in the charger or management boards to become
exposed during fast charging.
2) Again, software bugs or insufficient monitoring of individual cells
under heavy load, say apu starting, which caused one or more cells
to be discharge beyond safe limits.
Any out of band conditions should be logged by the charger, but there
appears to be no evidence of that from what we have been told, so a
hidden / intermittent software bug does start to look likely.
From info available, the chargers and monitoring have been used
elsewhere, but the software would be different and specific for each
application. Bugs can take years to become exposed in some cases and
only under certain sequences of events or timescales of operation. The
battery subsystem is still a very new product.
If the charger hasn't logged the real time sequence of events that led
up to the failures, then that is a deficiency in itself, imho...
Last edited by syseng68k; 3rd February 2013 at 22:58.