Shimano Di2 SM-BCR2 Battery Charger This is the Di2 battery charger for Dura-Ace 7970 and Ultegra 6770 Di2 systems. Di2 Battery, battery charger, and power cable are universal between Dura-Ace 7970 and Ultegra 6770 Di2 systems. Battery charge for 7970 and 6770 Di2 systems. Manufacture Part Number: ISMBCR2 Please Note: All Di2 components on the bicycle require the same firmware version. Using Di2 components with different firmware versions may cause malfunctions. To update the firmware on your components, use the Di2 system checker from Shimano by clicking here. | Shimano | Di2 Sm-Bcr2 Battery Charger Smbcr2 Charger For Internal Battery Btr2