Strange Di2 problem

[cyclespeed]

Yesterday out reconnoitring a route, I laid my bike down by the side of the road for 5 minutes.

When I got back on, the Di2 was totally dead. Nothing. No response from shifters, no lights on EW90, holding EW90 button did nothing, totally unresponsive.

Took seatpost out and disconnected battery. Reconnected - nothing. Same.

Just as I decided to ride home, stuck in a low gear (I'd been climbing!) it came back on just like that, and shifted perfectly the rest of the ride.

Today, 10k ride, then 40, all shifting perfectly. Then stood bike up for 1/2 hour or so and started ride with clients. Di2 dead again, nothing at all. Had no choice but to ride in 1st gear (!) for 1.5km, pressing all the buttons like crazy, nothing.

Then suddenly it starts up again, all fine for the rest of the ride.

This bike is full 9070. Battery was showing flashing green charge. No Dfly on this bike.

My idea is that it's going into 'Sleep' mode, but not waking up. If it was a loose battery connection, surely it would go on and off during the ride as the bike hit bumps?

Obviously I can't work like this, being a lottery as to whether the Di2 will work or not!

Any ideas welcome! Thanks.

[goodboyr]

The only time I've seen that symptom is from a connection that's not fully plugged in. I would check the line from junction b to the front junction. Make sure they are truly "clicked" in. Or perhaps cable damage. But never seen the "sleep mode" problem you theorize.

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[cyclespeed]

Thanks, I'll check the Junction B in the BB, but this bike has been fine for almost a year prior to this.

It has to be battery related as if any other component had a loose connection I would lose just that one component, not everything.

Or maybe EW90 is faulty?

[Delorre]

Last year, when my battery started failing, I also had a 'sleep mode' issue with the bike. When I started a ride, the FD would not do anything the first minute or so (rear was fine from the first shift), and than suddenly, everything was fine, even for multiple hour rides. Other thing, at that time, battery life began to shorten very strongly, and needed a charge every 300 or 400 km, and wile charging, went from red to green in something like 10 or 15 minutes, instead of 1 hour or more. i ended with a new warranty battery, and eveythng was fine again.

[Pokerface07]

Sounds like a loose/damaged cable, quite possibly the one that goes from the battery to junction box (b). Most other loose/damaged cables would still give you some form of function or lights on the A junction box.

[agravic]

strange indeed. any possibility of condensation inside the wiring connectors or junction boxes?

[cyclespeed]

strange indeed. any possibility of condensation inside the wiring connectors or junction boxes?

No, in Majorca, too hot and dry for that!

I gave the bike a full charge last night, it seemed to take quite a long time to go fully green, but was using a laptop. (Mac unfortunately....)

Will see how it goes today, but may buy a new battery to be on the safe side.

[eins4eins]

I had an issue with the di2 as well. charged the battery (2 months old, bought new from LBS) the evening before to 100%. the next morning I took off, wanted to shift and nothing happened. Completely dead, no lights, no nothing. went back inside, pulled all plugs, checked every connection. Didn't help.
I then plugged in the old battery I had laying around (hadn't been charged since I bought the new one) and everything was fine. Went for a 7h ride, without any problem.
Are there faulty batteries out there?

[thencameyou]

this happened to me when my old internal battery was dying. highly likely to be battery.

[BdaGhisallo]

100% it's the battery or the front junction box. I have had problems with batteries holding a charge before and it was the junction box causing the battery to drain prematurely.

[toiyuet]

IMO, 99.99% about the battery, which couldn't detect by any software or hardware by Shimano.

[Pokerface07]

It's not necessarily the battery. If it was going dead and staying dead until a recharge, then it's the battery. But this is an intermittent problem which leads me to think it's a cabling issue. My first and simplest solution would be to replace the cable from battery to junction B and see if that solves the problem. If not, it **could be the plug into the battery itself. So replacing the battery would be the next thing to do.

I've had a battery go dead/faulty but that gives different symptoms to what the OP is describing.

[deltree]

strange indeed. any possibility of condensation inside the wiring connectors or junction boxes?

No, in Majorca, too hot and dry for that!

Only time I've had this problem was watching a stage of the TdF. Bike sat in the sun for a few hours, went to ride home and Di2 was dead, same symptoms as you described. Happened to puncture a tub on the way back too, bike was in the shade while I faffed around with swapping tyres. Hopped back on and Di2 was working again

[cyclespeed]

Interesting; both times this happened, the bike was in full sun, but it's not THAT hot at the moment, only about 23'C ish.

Really busy running tours at the moment, so haven't had time to check much.

Bought new BT-DN110 today as a safeguard; this bike has the older BTR2 so it was on the cards anyway.

140km today with lots of pauses and no 'deadness'.

[TurboKoo]

Where and how have you installed battery? If it's wrapped in bubble plastic it might get too hot.