MM43:
Charger faults - Fan speed, CPU Temperature, Voltage, Current, Power, Stored fault history.
Battery faults - Abnormal temperature, Temperature sensor circuit, Cell unbalance sensor unit.
LED display - Eight-character alpha-numeric.
Diagnostics - Self test, Output voltage, Output current, Operating hours, Temperatures, Power.
Time - Date, Software revision.
Charge mode - Bulk charge mode, Topping charge mode, Trickle charge mode.
The likelihood of their flagship B787 charger providing less data than
above would IMHO be highly unlikely.
Ideally, yes, but the devil's in the detail. It doesn't say, for example, if
temperature is sensed for each cell, nor does it say what the sample frequency
is, ie: how often data is logged and under what conditions; singly on a
significant event, or continuously in the background, much as an fdr would
during flight.
Some systems log all the data at fixed intervals or sample rates, with each data
log entry timestamped, so that faults that develop over time can be traced back
by reviewing all the records. If the charger only logs a subset of available data,
or logs at too infrequent intervals, then it's quite possible that events that
lead up to a serious failure will be missed in the log. .
Supposing that the JTSB and NTSB examined the charger records straight up and
found nothing untoward except the battery fail event, then it would be reasonable
for them to dissect battery cells in order to deduce a reason for that failure.
Possibly, but it's also possible that there's not enough data being logged in the
first place for an accurate assessment...