@kenneth house
those three incidents plus the battery pack that Secura burned up in 2006--do you suppose that overcharging just might possibly be involved here, considering the charred remains of a battery thermal runaway, even though supposedly the FDR did not show evidence of overcharge and thus thermal runaway did not occur.
There was no charge monitoring system attached to the battery that caught fire in 2006 at the Securaplane facility. This improper test set-up was determined to be the cause of the fire, not the design of the battery itself.
Both the JTSB and the NTSB have stated that they could find no faults with the charging system aboard JA829J (JL8) or JA804A (NH692) and both have ruled out overcharging as a possible cause.