WHILL Model Ci Li-ion BatteryDouble the effective range of the Model Ci with a spare second battery. This spare battery is small enough to fit in the space under the seat and only 8 pounds, making it easy to carry along anywhere your Model Ci takes you. Easy and quick to swap out when you're out taking on the world, and helpful to have on hand when your main device battery is charging. The perfect accessory to step up your riding experience. *This is for use with the WHILL Model