Di2 Battery losing charge

[rigged]

Wondering if anyone can offer some wisdom on how to solve a Di2 battery losing charge overnight issue. The group is Dura Ace, about 2 years old with limited use. The issue started happening recently for no apparent reason. Any feedback is appreciated. Thanks!

[oldpotatoe]

Wondering if anyone can offer some wisdom on how to solve a Di2 battery losing charge overnight issue. The group is Dura Ace, about 2 years old with limited use. The issue started happening recently for no apparent reason. Any feedback is appreciated. Thanks!

Did you do a firmware/software check of the system? Battery? On a PC?

Recent micro adjust of the front or rear der?

[rigged]

Did you do a firmware/software check of the system? Battery? On a PC?

Recent micro adjust of the front or rear der?

I have not done a firmware/software check of either. Are you suggesting that they may need to be updated?

As for micro adjust, I did have it adjusted at a LBS prior to the issue. Any ideas what that problem could be? Thanks

[oldpotatoe]

I have not done a firmware/software check of either. Are you suggesting that they may need to be updated?

As for micro adjust, I did have it adjusted at a LBS prior to the issue. Any ideas what that problem could be? Thanks

Perhaps but it should tell you if the battery has failed somehow.

If the der is trying to shift all the time, against a limit screw, it may drain battery.. Shift it to the extremes, cogset and fder wise and listen to see if the ders are trying to shift/move.

[zmalwo]

check your low limit screw on your rear derailleur. di2 RD is perfectly indexed so theres no need to limit the cage movement like mechanical group. when your rd is on 11t and if the screw doesn't let the rd go to the indexed limit the motor will keep trying to go the limit. That will spend your battery in a few hours and ruin the motor inside your RD as well.

[peanutgallery]

Back off like a 16th on the limit screws and get a firmware update. Shimano adjusted the battery software sometime in the last year or so

If the problem persists, your LBS can call it in. Replacement might be an option, shimano has been pretty good about doing solids when it comes to Di2

[rigged]

Thanks peanutgallery and zmalwo for your help. If the chain is not on the outer sprocket when it is not being used, then I would assume the motor it is not trying to get to the indexed limit. So I can test it in that scenario (I guess).

I was also thinking that it could be a faulty battery, so I charged the battery and unplugged it from the bike. I am thinking that if I plug the battery back into the bike after a few days and it has still lost its charge then the issue is with the battery. Does this make sense?

[BdaGhisallo]

I have had two DI2 front junction boxes that have gone rogue and caused the battery to drain very rapidly. If the limit screw adjustments and a firmware update don't fix it, find a spare junction box to swap out and try.

[rigged]

I have had two DI2 front junction boxes that have gone rogue and caused the battery to drain very rapidly. If the limit screw adjustments and a firmware update don't fix it, find a spare junction box to swap out and try.

Ok will keep that in mind BdaGhisallo thanks. Forgive my ignorance, but is there an application I need to download to my PC to perform the firmware update?

[stien]

It's the etube program, you can find it online from Shimano.

An easy check would be to check the battery level an hour after charge up with a multimeter. Or you can see if it's solid green on the bike. If it's flashing green already, old battery needs replacing.

[rigged]

It's the etube program, you can find it online from Shimano.

An easy check would be to check the battery level an hour after charge up with a multimeter. Or you can see if it's solid green on the bike. If it's flashing green already, old battery needs replacing.

Great, thanks very much for your help. Hopefully I can get to the bottom of this. Nothing worse than finding a window for a ride only to find that the battery is dead. Makes me think that the simplicity of mechanical shifting is preferable.

[rigged]

Closing the loop on this one: I made a minor adjustment to the limit screw and that appears to have done the trick. Battery is still fully charged one week later. Thanks again for the help.