Thanks for the replies so far and the style of connector !
Here is some more info
Currently shooting at 330 FPS
Motor Turbo 3000 middle pin motor (MC-128)
Version 3 gearbox ( steel bushings and gears )
It will fit nunchuck style battery with a lot of patience , Iv'e been told.
From what Iv'e seen on line - Stick style may be the best option.
I don't know enough about the different battery types ( Ni-cad, Ni-mah , Lithuim , and even mAH ratings and voltage )