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. One charge can give between 1000 and 2000 kilometre range depending on conditions and front mech operation (as this is the main power drain)….
– Shimano Dura Ace/Ultegra Di2 Battery Unit Groupsets & Build-kits – £37.99 (RRP – £)