Are the front and rear derailleur batteries interchangeable? August 14, 2015 18:49 Yes. Additionally, shifters use one CR2032 coin type battery each. Related articles What happens when an eTap® 2x11 battery is low? Will the shifts slow down? Will the shifter work intermittently? Will the parts stay “on” when the bike is on my car rack? How far can I ride on a fully charged derailleur eTap® 2x11 battery? How do I know when to charge the eTap® 2x11 derailleur or replace the shifter batteries? How long does it take to remove 2x11 eTap® shifter batteries? Comments 0 comments Article is closed for comments.