“Boeing also want to run all of their electrical power off of the engine aswell, and not have to carry anything such as batteries on board”

The electrical power for the aircraft comes from a generator connected to the engine gearbox. If there is an engine failure, the APU can be brought online to provide some engine power… On the 777, the APU and the each engine is designed to produce the same amount of elecrical power, so if the engines fail, something is going to have to be switched off! If the APU fails, then there is a RAT, or ram air turbine which produces power like a windmill… this only produces a small amount of power, only enough to maybe power the flight instruments. If that fails, then I think there are smoe batteries somewhere… not sure if the RAT or batteries provide the last of the power! But the chances of all of these failing are very remote, so perhaps Boeing could get rid of the batteries.