We're at the point where we have to decide where to dispose of the battery-packs and we shall put them here basically because we can. It unloads the centre-section, which is already carrying the weight of the passenger; it also allows for a safe approach from each corner in order to connect each power supply while remaining clear of propeller; and it avoids the need for a central bus or distribution board with the messy soldering which that would require.
The batteries in the diagram show the dimensions of a typical pair of seven-cell packs of around 22000 mAh wired in series to produce around 50 volts, together weighing in the order of six kilos (thirteen pounds) per pair.
