Di2 Failure - Help!

parkwalter
parkwalter Posts: 4
edited June 2020 in Workshop
I have a full Shimano Ultegra di2 8070 groupset on my Trek Emonda that until this week was working flawlessly for the past 2 years.

I was on a road ride with a friend and suddenly the di2 died; no shifting, no lights on my junction box, just nothing. I came home and plugged it in to charge thinking my battery was dead; got the flashing red "battery error" light on my charger.

I plugged the junction into my computer and opened e-tube which identified all of the components including the battery.

I disassembled the bike and tried my spare junction B, along with trying all of my replacement di2 wires I have as spares. After changing all of these, the di2 is still completely unresponsive.

My thought it that it's a faulty battery but just wondering what you all think this could be?

Comments

  • paulwood
    paulwood Posts: 231
    i've had a couple of batteries die for no apparent reason. Both under warranty luckily. Since then no issues
  • The interesting part; when I connect my bike to e-tube it recognizes all of the components, including the battery.

    Tried to go out on a ride today and shifting completely died, no lights, nothing.

    Then when I plug into computer for e-tube, shifting starts working again.

    I'm almost positive this is a faulty battery. I figure if it was a faulty wire the e-tube wouldn't detect that component. Any ideas?
  • lincolndave
    lincolndave Posts: 9,441
    Do any of you friends run di2, if they do ask if you can try their battery , or charge your battery , remove it and check the voltage , that’s if you have a voltmeter or fluke
  • StillGoing
    StillGoing Posts: 5,211

    The interesting part; when I connect my bike to e-tube it recognizes all of the components, including the battery.

    Tried to go out on a ride today and shifting completely died, no lights, nothing.

    Then when I plug into computer for e-tube, shifting starts working again.

    I'm almost positive this is a faulty battery. I figure if it was a faulty wire the e-tube wouldn't detect that component. Any ideas?

    Is that not power from the wall or PC that's making it work though. Definitely sounds like the battery.
    I ride a bike. Doesn't make me green or a tree hugger. I drive a car too.
  • @StillGoing I think you're right. I'm pretty sure what happens is that the battery is disconnecting completely from the system for some reason, and when I use e-tube it forces the battery to reconnect. I have a new battery arriving this week so hopefully that fixes the issue. I tested my spare wire set for both Junction A to Junction B and Junction B to battery and in both cases it did not fix the issue so I'm assuming it's the battery itself that is causing problems.