Lithium 40V 6AH Battery with USB PortThe StrikeMaster 40V Lithium Replacement Battery is 40V, 5 AMP Hour Lithium Ion Battery. The battery also features an internal battery management system for long life, 4 LED battery status indicators, and a 2-year warranty.WARNING: This product can expose you to chemicals which are known to the State of California to cause cancer, birth defects or other reproductive harm. For more information go to P65Warnings.ca.gov.