Originally Posted by
Psimet2001
Those batteries are backwards compatible to every etube generation though aren't they? meaning everything but first gen Dura Ace di2
The external batteries MUST have the proper external battery mount. This suggests that external battery brains are in the mount and not the battery. It took me three tries to get the proper external battery mount. Finally broke down and actually asked a mechanic familiar with the stuff. He print me out the Shimano interchangeability chart. If you don't have the proper battery mount the system won't even turn on. Seems as dead as a doornail.