Description: This external battery pack works with the built-in battery pack to provide power, allowing you to use an external battery pack to extend your riding distance. Our batteries are made from high quality cells to ensure a long service life.The battery of the Kingbull e-bike is also set up with a key to keeping your battery safe. Features: Lithium-Ion cells The battery weighs 7 lbs. * Backup battery installation guide *Does not come with a charger.