Just throwing a thought out there...
If I am reading this correctly and the main battery IS supposed to be the last chance saloon if all other electrical power fails on-board, could the battery circuit design have been 'compromised' to allow the battery to be able to deliver 100% power in that particular scenario and be able operate outside the 'safe' operating limits ?
Or put another way, could the charging/conditioning/regulating circuits that are required to keep these batteries operating safely within their exacting operating environment, hinder the ability to allow the battery to provide the higher sustained current that is required in such a critical situation?
With a more direct (high current) connection from the batteries to the DCbuses in these emergency/failsafe situations, it now lacks the finesse needed to keep these batteries operating within safe working limits. Or due to the connection, the control circuitry isn't up to protecting the batteries from the higher running voltages that are present on the buses when the aircraft is powered up? I know someone further back has mentioned a blocking diode in one of the 787 threads – can’t remember if something similar is fitted or not 
As Lyman mentions above, could the certification tick box requirements by playing some part ?
Last edited by E_S_P; 28th January 2013 at 14:52.
Reason: FatFingers