I was just wondering if it was possible to fit the 6870 Di2 on a 2012 Cannondale SuperSix ? It has no internal wiring. I think the 6870 Di2 has a new round long battery that only goes in the seat post. I don't think I could get a wire out of the top of the seat post.

Here is an internet picture of my 2012 cannodale supersix

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I was told on another forum that the battery should fit the seatpost.

I guess I could drill a hole in the frame but it would void the warranty.

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  • 2
    A 2012 frame is coming on 5 years old, depending on how much riding you do you may find that it's already up to or passed it's expected lifetime for warranty in cannondales eyes. A lifetime warranty is on the frames life, not yours!
    – DWGKNZ
    Commented Sep 25, 2016 at 17:30
  • Also is a drink bottle cage battery not an option?
    – DWGKNZ
    Commented Sep 25, 2016 at 17:32
  • Yeah bike is getting on. Maybe time for a new one and keep it for winter. They changed the battery from one that fits under bottle cage to one that fits inside seat tube.
    – Aindriú
    Commented Sep 25, 2016 at 17:43
  • 2
    FWIW, the external batteries didn't just go away. You can still use them on all the Di2 groups. Commented Sep 28, 2016 at 7:55

1 Answer 1


I wouldn't modify a carbon frame as it'd be difficult to detect the beginnings of delamination where you drill it.

Internal wiring is optional. You'll need an SM-JC40 for external wiring, a SM-BTR1 and SM-BCR1. The charger which connects to the front junction will only charge internal batteries.

  • Thanks for the post. I'm checking out if I can use the older model's battery with the newer 6870
    – Aindriú
    Commented Oct 3, 2016 at 20:57

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