merlinextraligh

The Di2 on our gravel tandem just stopped working dead as a door nail. It wouldn’t shift, wouldn’t link to Garmin; wouldn’t display any lights on the junction box; wouldn’t charge, or even register that it was on the charger. I checked all the connections and they were all good.

it had randomly stopped shifting once before, but started working again.

It appears to be a battery failure. I swapped out a battery from another bike and it works fine again. Odd thing is the battery is only 1 year old, was well charged, and never showed any signs of aging, such as draining fast, or not holding a charge. Any one else expereince a sudden random battery failure?

Makes me think on an extended trip that carrying a spare wouldn’t be a bad idea.

Steve B.

They are generally pretty reliable for a few years. Mine is 3 now and not showing any issues of premature discharge. I expected to need to replace about now, am not going to. I also wouldn't bother with a spare. You might contact Shimano, it could be a bad battery, who knows maybe they'll replace it.

tempocyclist

Sounds like a failure of the battery. Very rare. I've got an original 10-speed Di2 bike that's going on 6 or so years of use and the battery is fine.

But more importantly, WE NEED TO SEE PHOTOS OF THIS GRAVEL TANDEM! 😃

jaxgtr

A buddy of mine had this happen on a new bike last year that was only 3 months old. Shimano has 2 yr warranty on the batteries.

Iride01 

Do you have a SM-BCR2 or whatever came with it? If you load eTube project on your computer and hook everything up then it will tell you what Di2 stuff it sees. Whatever is missing might be bad, or the last show component in the daisy chain of components might be a bad connection to the next.

You've had this long enough to have gone through several battery charges and know that you are doing it right? Di2 doesn't like low amperage chargers.

blakcloud

Sorry to hear about your dead battery but thank you for reminding me to charge mine. I haven't worked this task into my individual consciousness when working on my bike. New habit to incorporate.

merlinextraligh

Haven’t checked it on the computer, but it went from 40% charge to dead as a door nail, and it works fine when I switched out the battery. So pretty sure it’s a battery failure.

it does appear to be a fairly low likelihood event. I’ve got 3 bikes with Di2. First one I replaced the battery at 5 years, not because it was failing, but to get a new battery capable of a firmware upgrade. Second bike is 3 years old and going strong. Ironically, the newest battery failed at 1 year, just luck of the draw.

BHG6

I have 2 11 speed Di2 bikes and have never had an issue either. One battery is 3+ years old and the other 5+. Both bikes are stored in the garage which routinely hits 115 degrees durning the summer. They’ve held surprisingly well for me, at least.

Sy Reene

With 12s Di2 on the horizon, is it time to stock up on the 11s parts? Though perhaps the battery will be the same?

popeye

We have 2 DI2 bikes and the Ultegra battery failed at just over a year. For some reason the DA has better battery life even after replacing the bad battery.

look566 rider

Sorry about battery issues...

Further confirmation (for me) that a bike should be totally mechanical without reliance on electricity to do simple tasks. Not trying to start any garbage.

rm -rf

I charge mine once it gets to blinking green. That's under 50% charge. I used to wait until solid red, 25% charge. But I don't check every ride, and twice ran it down enough to stop the front derailleur from shifting.
I got a new battery after 5 years. The old one still worked, but I had to charge it weekly, and decided it was time.

I didn't push in the connector all the way, so nothing worked at first. There's a slight click with no electric connection yet, then a stronger second click after using a bit more force.
~~~~
Longevity!
I got the bike in Sept 2014, Ultegra Di2 with the seatpost battery. It's now been at least 31,000 miles.
Both derailleurs are still precise, with no pivot wear to make it sloppy shifting.
The shifter buttons still work perfectly.

I'm actually surprised it still runs like new.

Atlas Shrugged

Then why post this?

Andy Somnifac 

Because he wants to start some garbage?

Psimet2001 

12s batteries are different as they also act as a junction box but I would "guess" they would be compatible with older systems... but the specifics are to be determined.

Psimet2001 

Generally - unplug the battery from the system for 5-10 minutes. Plug it back into the system then attach the cable to a computer and run etube for a system check. See if it recognizes the battery and if so if there is a firmware update. Sometimes when those batteries fall too low the charger won't even recognize them or charge.

IIRC there was a "bad" batch - meaning I have heard of some from a particular point in time that seemed to have issues and were replaced. That said I have no specific data on that. Batteries with them don't really fail often . Bring a spare on your trip as insurance if it makes you feel better. Have your shop call shimano. They will most likely warranty it but the problem now is availability.

prj71

I agree with this.

eduskator

Not on my end.

It's the first time I hear of a DI2 battery failure. These things are built like tanks and usually last for a long time. Have you tried calling shimano to see if they can do something about it?