Also, the Airbus 330/340's have a hydraulic motor generator that run off the green system. There is a green EDP on each eng/wing. If one eng can turn you don't run out of electrons.
If the eng stops (ie. gliding) you can drop the RAT. It will also run the emeg gen.
You only need the batts (2) below 50Kts when the RAT gives out.
Of course, after all that you are down to the magnetic compass, torch and mobile phone (and a prayer).