Di2 battery drain issue
I've had my Di2 system for over a year(?) now, and generally, everything works well. But I've had a problem on more than one occasion where the battery will drain after working on my bike. When I'm just doing a lube refresh, what I do is just flip the bike over, wipe the chain down, and re-lube. I always shift into the big ring and little cog to do this. So, after flipping the bike over, I'll turn the cranks, and shift into this gear combo. After finishing, I'll just flip the bike over, and leave it in that gear combo. But it seems like every time I do this, the battery will drain out before the next ride. Usually I'm lubing the chain after a ride, or well before I go out again, so I'm not immediately jumping on the bike afterwards. I can alleviate this problem by simply shifting a few gears on the bike before putting it away. Not sure what I'm doing to drain the battery, has anyone ever experienced this problem?
|
Hmm, this is a longshot, but maybe one of the "shoulder" buttons is getting stuck in the down position when you flip the bike over, and that's causing the system to stay active and run the battery down? I'm talking about the buttons on the newer Di2 levers that are hidden under the hoods, sort of on the knobby part above the brake pivot.
|
Originally Posted by cthenn
(Post 20954375)
I've had my Di2 system for over a year(?) now, and generally, everything works well. But I've had a problem on more than one occasion where the battery will drain after working on my bike. When I'm just doing a lube refresh, what I do is just flip the bike over, wipe the chain down, and re-lube. I always shift into the big ring and little cog to do this. So, after flipping the bike over, I'll turn the cranks, and shift into this gear combo. After finishing, I'll just flip the bike over, and leave it in that gear combo. But it seems like every time I do this, the battery will drain out before the next ride. Usually I'm lubing the chain after a ride, or well before I go out again, so I'm not immediately jumping on the bike afterwards. I can alleviate this problem by simply shifting a few gears on the bike before putting it away. Not sure what I'm doing to drain the battery, has anyone ever experienced this problem?
|
Always do the easy and cheap thing first.
Forget about B screws and limit screws for now. Hold the bike in the air using the saddle and spin the cranks a few times after flipping the bike back over. If it shifts into a different gear then that's your problem. I'll bet the Di2 lever has been pressed when it is flipped and the bike is trying to shift into the next gear. |
Originally Posted by TimothyH
(Post 20954899)
Always do the easy and cheap thing first.
Forget about B screws and limit screws for now. Hold the bike in the air using the saddle and spin the cranks a few times after flipping the bike back over. If it shifts into a different gear then that's your problem. I'll bet the Di2 lever has been pressed when it is flipped and the bike is trying to shift into the next gear. As a PSA about using Di2, always make sure nothing is causing the shift buttons to be pressed if you transport the bike on its side in the back of a car. |
Elevators turn their own door motors off when the door fails to close. This would be a good place for that kind of logic.
|
Originally Posted by Steve B.
(Post 20954910)
As a PSA about using Di2, always make sure nothing is causing the shift buttons to be pressed if you transport the bike on its side in the back of a car.
|
Originally Posted by TimothyH
(Post 20954899)
Always do the easy and cheap thing first.
Forget about B screws and limit screws for now. Hold the bike in the air using the saddle and spin the cranks a few times after flipping the bike back over. If it shifts into a different gear then that's your problem. I'll bet the Di2 lever has been pressed when it is flipped and the bike is trying to shift into the next gear. |
Originally Posted by TimothyH
(Post 20954899)
Always do the easy and cheap thing first.
|
Originally Posted by TimothyH
(Post 20954899)
Always do the easy and cheap thing first.
Forget about B screws and limit screws for now. Hold the bike in the air using the saddle and spin the cranks a few times after flipping the bike back over. If it shifts into a different gear then that's your problem. I'll bet the Di2 lever has been pressed when it is flipped and the bike is trying to shift into the next gear. Hmm. On my Di2 bike, hitting a button while NOT pedaling will indeed move the derailleur, just like on a mechanical system. So I'm not sure that this is the issue. But I sure would like to see the OP come back to tell us if this did work. 'Course, no one suggested another obvious solution: buy a workstand and service your bike right-side up. |
Originally Posted by Koyote
(Post 20972803)
Hmm. On my Di2 bike, hitting a button while NOT pedaling will indeed move the derailleur, just like on a mechanical system. So I'm not sure that this is the issue. But I sure would like to see the OP come back to tell us if this did work. 'Course, no one suggested another obvious solution: buy a workstand and service your bike right-side up. |
Even on a work stand, he could hit the button when installing the bike on/taking it off the stand.
After reading this thread, I checked my bike because I've had this issue occasionally. Sure enough, the limit screw was just a bit too tight, and I could semi reliably make the shifting go up to the largest cog but not "give up trying", as if it thought it wasn't fully there yet. Only time will tell if this fixed it, but after seeing the behavior, I'm pretty sure it will. |
Originally Posted by Metaluna
(Post 20972837)
I think the issue is that when you don't pedal, the derailleur gets jammed by the chain so it ends up stuck between gears and continuously drawing power (which is not only bad for the battery but must be terrible for the stepper motor and various mechanical bits like pivots). Pedaling allows the chain to shift, both clearing the jam and indicating that the RD was stuck in a bad state. I suspect that there's enough slop in most chains that you could get away with one shift on the RD, but if a button is stuck it will try to do multiple shifts until it jams.
|
Originally Posted by faulker479
(Post 20956405)
He said "I can alleviate this problem by simply shifting a few gears on the bike before putting it away" It may be that a shift button is inadvertently being pushed when he flips it back over, but the problem is only while in large chainring an smallest tooth cassette cog. So yes spinning the cranks is the best way to tell if a button was pushed, but having a High Limit screw that is too tight seems to be the real issue. Never mentioned the B screw.
|
I can shift a couple of clicks without spinning the crank -- I don't think it's straining the motor, the chain is just at an angle.
The limit screw sounds like the problem. It needs a gap to allow an over shift. The low limit (largest cog) is adjusted without extra clearance. I could see this draining the battery overnight. If so, riding in the smallest cog would drain it too! OP, do you ever leave it in the smallest cog after a ride (without flipping the bike over)? (Or perhaps the hidden top of the hood buttons? but they aren't running the motors.) From the dealer manual DM-UL0001-02.pdf Shift the rear derailleur to the smallest sprocket, and then tighten the top-side stopper adjustment bolt until it touches the stopper at the position where the rear derailleur finally stopped. From this position, turn the top adjustment bolt counterclockwise one turn so that an over-stroke allowance can always be maintained. ~~~ The largest cog is adjusted closer: Shift the rear derailleur to the largest sprocket, and then tighten the low adjustment bolt until it touches against the stopper. If it is tightened too much, the motor will detect a problem and gear shifting operation will not be carried out correctly. |
All times are GMT -6. The time now is 05:28 PM. |
Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.