What are the dimensions of the actual battery before you put it in a bag (could get a bag / modify an existing bag to fit )
My bag battery is the smaller 36V 10AH. The OP wanted something bigger, 36V15AH.
Dimensions:
36V10AH 17cm x 7cm x 7.5cm
36V15AH 21cm x 8.5cm x 7.5cm
My bag houses also the 85TS controller. There isn't much excess wires, they are also tucked in the bag. The LCD is built into the stem. I did not bother with the throttle as starting off on the 85TS is instantaneous. The overall result is pretty neat and pleasing.