Originally Posted by the_canuck
Ya, but if they plug the plane in while on the ground you get Japanese power on the plane.
I can see a design engineer designing the charger for balanced 3ph power and then not consider the Japanese who are one of the only countries in the world that ground one corner of a delta 3ph power. It causes all kinds of issues with 3ph power supplies. It's hard to tell what it would do to a battery charger.
Airplanes aren't plugged into the wall at the hotel! The ground power is the same volts and freqs as the system on the airplane or it won't accept the power. The airplane's battery charger is powered by the airplane's electrical power system, so it's just going to be a dead airplane electrically unless the proper ground power is present.
If there is no ground power, the airplane's own APU is used to power the airplane and the battery charger is still powered by the airplanes electrical system.