Grintech's modular LiGo battery was born in response to the massive transportation restrictions placed on large lithium ebike packs. Properly certified batteries under 100 watt-hours are even allowed aboard passenger aircraft with your carry-on luggage. Why not use this as the building block that can be easily re-assembled into a large battery?
After much design consideration LiGo decided to implement this as a flat 10s x1p 18650 cell layout, with every battery having its own independent BMS circuit and each pack being potted to protect against the elements.