Lobster External Battery Pack The Lobster External Batter Pack allows your to get the most out of your time on the court. The external battery pack provides an additional 4-8 hours of time on the tennis court. Compatible with any of the elite series ball machines.Includes a large 18-amp sealed lead-acid battery, battery cord with connector, XLR adapter, 1-amp fast battery charger, and a canvas carrying bag. Note: Larger items like court equipment, and tennis ball machines (often made to order) may not be stocked in our Baltimore warehouse. These items are carefully assembled and shipped directly from the manufacturer. Please give us a call if youd like to pick this item up from our store so we can check availability and prepare your order. California State Tax Note: The Lobster External Battery pack is built-to-order and ships directly from California, therefore all shipments to California must pay applicable CA state sales tax.