Shimano BT-DN300 Built-In DI2 Battery - For Dura-Ace 9150 and Ultegra R8150 Systems, Compatible with SD300 WiresShimano Di2 Batteries. Must purchase battery, charger, and power cable to complete the system. All Di2 components on the bicycle require the same firmware version. Using Di2 components with different firmware versions may cause malfunctions Use Di2 system checker to update component firmware from http: e tubeproject. shimano. com Product Specifics Today's Stock Status 10+ Available to ship in 2 4 Business Days UPC: 192790894720 EAN: Not available