Shimano 7970 Dura-Ace / 6770 Ultegra Di2 Battery – N/A
The power house of Di2 is the long-life 7. 4V Li-Ion Shimano 7970 Dura-Ace / 6770 Ultegra Di2 Battery that is both compact and reliable, taking shifting effort away from you. Excellent sealing and reliability have been proven through repeated field tests in various riding conditions, including extreme temperatures, rain, mud, and cobble stone roads. Using a hard wired battery system which is both light weight and accurate compared to current wireless technology (as a wireless system would require 4 batteries: one for the RD, one for the FD, and one for each shift lever). The use of a single small and discreet battery is light weight, efficient and creates a robust and reliable system.