This is the extended range removable second battery for the Cooler Kub 250S.
It’s a bit bigger than the standard battery, giving you even more miles, so cannot be fitted in the upper 'fuel tank', but clipped in on the lower part of the frame and is compatible with the original charger.
It's lockable and comes with keys!
36v - 20aH - extended range
Ride Cool, for farther.