Attached are some photos of the batteries. Each of these contains 48 cells.
So that a 4x12 array of the Swing cells, each of which is probably a pair of 18650 cells wrapped together and connected in parallel, so essentially an 8x12 array of 18650's... that means something greater than
65 mm tall
8 x 18 mm = 144 mm wide
12 x 18 mm = 216 mm wide
and 48 x 90 g = 4.3 kg
occupying about 2 litres
... per module
Capacity is 4400 mAh per Swing unit, so 781 Wh per module (nominal).
I was planning to connect 16 cells togther in parallel and then 80 of these batteries together in series.
So 80s16p Swing units, or 80s32p 18650 cells, for 296 volts (nominal). That's 1280 units (or 2560 18650 cells) in 27 modules each configured as 3s16p, totalling 115 kg of bare cells plus module overhead, plus enclosures.
It's actually 26 2/3 modules, so perhaps 81s16p Swing units (or 81s32p 18650 cells) for 300 volts (nominal). That's 1296 units (or 2592 18650 cells) in 27 full modules.
Total volume would be about 60 litres, which doesn't seem unreasonable at all. The challenge is that it is a lot more difficult to pack a couple dozen rigid bricks than the same volume of liquid in a tank which can be shaped to conform to the available space.
I wouldn't expect all of that to fit in the front with the motor and controller, and the space used by the fuel tank is not going to conveniently fit the modules. I'm looking forward to seeing the pack design.