I expected better from goped!
1. I think its very very dangerous to have exposed (male) connectors on the battery side, its really basic.
2. Another problem I can see with this setup is not having LVC per cell.
3. The use of DB8 is not the best choice here - once the cells voltage diff (I think it start at 5 or 10 mV) the DB8 will try to balance the cells. 38120S LifePo4 cells have a very flat discharge curve, however, think what will happen if one cell's nominal voltage is 20 mv lower than all other... this happens, and it meens the DB8 will empty the pack when standing and unbalance the whole pack. the DB8 should be active only when charging!
I own and love a hoverboard, but this solution looks like something a kid hacked at home (except for the plastics - I like the black spacer).