21700 battery wraps are thin plastic sleeves used to re-wrap or repair the exterior of 21700 lithium-ion batteries. The wrap acts as a protective layer for the battery, preventing it from short-circuiting and causing a potential safety hazard. A damaged battery wrap can expose the metal casing, leading to an increased risk of electrical shorts or shock hazards. With a 21700 battery wrap, users can maintain the integrity of their batteries and prevent damage to the internal components. These wraps come in different colors and designs, allowing users to personalize their batteries and differentiate between multiple cells. It is important to ensure that the new wrap is applied correctly, as any bubbles or wrinkles can affect the performance and safety of the battery.