From the Reuters article:
Boeing spokesman Marc Birtel said that the investigation has not showed that overcharging was a factor and that the 787 had quadruple-redundant protection against overcharging in any case.
The admitted wiring error or component failure that allowed the APU battery to power loads that should only have been on the bus from the main battery leads me to conjecture that in the ANA case the quadruply redundant protection may have been at most singly or doubly redundant.
