Di2 internal battery draining (6870)

londoncommuter

Apologies if this has been posted elsewhere but I'm having an issue with my brand new 6870 build.

I built the bike up and charged the battery a couple of months ago and checked everything was properly working on a quick ride (which it was) and the bikes been sat inside since then waiting for a nice dry weekend.

On checking on Friday, the battery had completely drained in the intervening time despite not having been used.

I charged it fully on Saturday morning and have just checked and it's again completely flat with the battery light on the junction box not even coming on at all when I hold a lever in to test.

I've seen mention of shorts in junction box A causing this. Does this sound likely?

I really don't want to start taking everything to bits as it's all internally wired so please please please can someone wise tell me exactly what the cause is and how I can fix it with no grief!

Thanks for any advice.

JonCarpenter

Same thing happened to me a couple of months ago. Shop did a diagnostic which said there was nothing wrong. Only thing that worked for me was to replace the battery. Since then everything has been fine. Two months of riding and new battery has not moved from full charge.

pippi_langsamer-2

Id send it back from whence it came and get them to replace the obviously faulty battery.

Mine stood idle for nearly six months from new, and since using it this season hasn't required charging yet...

bernithebiker

How are you charging it? (It makes a difference).

CiB

Check that the limit screws and indexing are absolutely spot on. If they're not and you leave it in the lowest gear (biggest cog on the cassette) it continues to try to complete the change into 1st, which discharges the battery. The best way to check this is to hook it up to the Etube s/w and run the full diagnostics - it'll report that and any other errors.

londoncommuter

Thanks for all of the tips so far. Still not sure completely what's going on with it so I'll check again tonight if it's working after charging yesterday.

Maybe a stupid question but I don't seem to be able to access the error checking function on etube as I only have the SM-BCR2 charger/interface rather than the all singing all dancing SM-PCE1. Is that right?

Also, when you press and hold a lever for 0.5s to check the battery level on junction box A, is it really any of the four levers you can press or do only some of the work depending on where the derailleurs are (sorry that even sounds stupid as I type it)?

bernithebiker

londoncommuter wrote:

Thanks for all of the tips so far. Still not sure completely what's going on with it so I'll check again tonight if it's working after charging yesterday.

Maybe a stupid question but I don't seem to be able to access the error checking function on etube as I only have the SM-BCR2 charger/interface rather than the all singing all dancing SM-PCE1. Is that right?

Also, when you press and hold a lever for 0.5s to check the battery level on junction box A, is it really any of the four levers you can press or do only some of the work depending on where the derailleurs are (sorry that even sounds stupid as I type it)?

londoncommuter wrote:

Thanks for all of the tips so far. Still not sure completely what's going on with it so I'll check again tonight if it's working after charging yesterday.

Maybe a stupid question but I don't seem to be able to access the error checking function on etube as I only have the SM-BCR2 charger/interface rather than the all singing all dancing SM-PCE1. Is that right?

Also, when you press and hold a lever for 0.5s to check the battery level on junction box A, is it really any of the four levers you can press or do only some of the work depending on where the derailleurs are (sorry that even sounds stupid as I type it)?

Correct re. the charger. You need the other one to access the error checking function - I borrowed one from my LBS when my 9070 froze up.

For battery check I press and hold the large left lever, haven't tried the others, doesn't matter what gear you're in.

Don't forget to check how you are charging - is your USB plugged into a transformer in the wall or into a computer? It is not the same thing.

Bar Shaker

I would also check you are using the latest OS. Although your problem sounds like hardware failure, the 3.x series includes enhancements on battery usage.

Holding any shift buttons will display the battery status on the junction box.