EMTB power keeps cutting out an hour into my ride

Steve b

Member
Apr 11, 2021
26
6
Peak District
I have a Haibike All Mountain 7, 2 years old, approx 3000 miles. My ride starts OK, but after an hour or so I lose power suddenly and the controller turns off. I can then restart the controller but after about 3-4 minutes the power cuts out again. This continues to the end of the ride. It seems that once the power has cut off the first time I can't access anything greater than Standard/Sport assist (perhaps even Eco, hard to tell). I have cleaned the contacts points of the battery/pins with electrical cleaner and the battery is kept indoors. Any ideas - Thanks very much
 

The Hodge

Mystic Meg
Subscriber
Sep 9, 2020
3,797
7,871
North West Northumberland
Bosch motor ..just out of warranty?..get to to your LBS for a diagnostic check .pronto .
Different issue on my motor 1 month out of warranty with all sorts of error codes & Bosch had no quibble changing it .
It's got to be worth an ask ..
 

Zimmerframe

MUPPET
Subscriber
Jun 12, 2019
13,907
20,612
Brittany, France
Bosch motor ..just out of warranty?..get to to your LBS for a diagnostic check .pronto .
Different issue on my motor 1 month out of warranty with all sorts of error codes & Bosch had no quibble changing it .
It's got to be worth an ask ..
Could be a PW-X2 .... always difficult to know with the Haibikes :)
 

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,283
4,780
Weymouth
If it is Bosch/Purion controller it could be the Purion batteries running flat??
 

Steve b

Member
Apr 11, 2021
26
6
Peak District
Bosch motor ..just out of warranty?..get to to your LBS for a diagnostic check .pronto .
Different issue on my motor 1 month out of warranty with all sorts of error codes & Bosch had no quibble changing it .
It's got to be worth an ask ..
It's a Yamaha PWx2, no error codes. Its my second motor, the other one just died, this problem seems different
 

Steve b

Member
Apr 11, 2021
26
6
Peak District
If it’s always an hour into your ride it could be a thermal cut out?
Yes, roughly, the ride starts OK, no odd noises, power levels working as normal. Then suddenly mid ride the power cuts out. Having read a few articles I am beginning to think it is a battery issue. But no error codes, no overheating (as far as I can tell) and battery levels seem fine....
 

Zimmerframe

MUPPET
Subscriber
Jun 12, 2019
13,907
20,612
Brittany, France
Does it always cut off at the same battery level ? You say about an hour, but different terrain and modes would use different amounts of battery.

Does the motor feel lower or less effective before hand ?

The PW-X2 has bushings which should be greased in theory, it could be that the motor's getting tighter as it gets warmer, though you'd expect that to happen sooner than an hour if that were the issue.
 

Steve b

Member
Apr 11, 2021
26
6
Peak District
Does it always cut off at the same battery level ? You say about an hour, but different terrain and modes would use different amounts of battery.

Does the motor feel lower or less effective before hand ?

The PW-X2 has bushings which should be greased in theory, it could be that the motor's getting tighter as it gets warmer, though you'd expect that to happen sooner than an hour if that were the issue.
Hmmm, could be about the same battery level, both recent rides have been roughly the same route and the power shut off in a similar place. The motor seems to lose power immediately before shutting down. No noises from the motor, soon as I switch the controller on again I get power, just not as much. I am suspecting battery problems...
 

Stihldog

Handheld Power Tool
Subscriber
Jun 10, 2020
3,171
4,397
Coquitlam, BC
@Steve b , you’ve described, almost, what happened to me. (Bosch gen4 2020 Rail 9.7, Kiox, 625w, similar mileage).
Motor cut out 20min into my ride, usually in the same spot (gravel access road). I could count on this happening, at this stretch of gravel road, almost every time. Not too steep, not rough, but not smooth either. The cut off did happen in another area, once, while I was passing another eMTB. Never on a decent or a rock garden climb.

When I would lose power assist, I usually peddled through it until power returned. If the Kiox completely lost power then I would have to stop my bike and restart the Kiox. To me this was a mystery. I had the latest update, motor was quiet, no weird rattle, wet-ish environment, rode almost daily for 15-25kms, full charge each time, (fresh underwear each time). I was searching for anything. Everything looked fine.

All the suggestions here are possibilities and this forum is where I finally found a solution. Poor battery connection. The fix suggested was to slightly reposition the battery connection plate (1mm maybe) by loosening the plate bolts and prying it slightly closer towards the battery. Retightened and checked for battery fit.
Problem solved. Never had a vibration frequency induced cutoff again. I’m not sure if I got lucky but I could have searched other possibilities first and eventually made it to the connector issue. (I also stopped searching for a buried Flux-Capacitor in that spot 😉).
 

TQFreak

Active member
Dec 2, 2022
174
216
USA
I have a Haibike All Mountain 7, 2 years old, approx 3000 miles. My ride starts OK, but after an hour or so I lose power suddenly and the controller turns off. I can then restart the controller but after about 3-4 minutes the power cuts out again. This continues to the end of the ride. It seems that once the power has cut off the first time I can't access anything greater than Standard/Sport assist (perhaps even Eco, hard to tell). I have cleaned the contacts points of the battery/pins with electrical cleaner and the battery is kept indoors. Any ideas - Thanks very much
The display battery is low. Replace the display battery.
 

TQFreak

Active member
Dec 2, 2022
174
216
USA
There are two batteries. One is rechargeable from the downtube and one is not rechargeable sits inside the display (or controller). If the battery inside the display is low it may cause the issue you just explained. I believe even the user manual from your bicycle tells it. If it is 2 years old then the battery inside the display (or controller) is likely on the dead row and it is a good idea to replace it.
 

Steve b

Member
Apr 11, 2021
26
6
Peak District
There are two batteries. One is rechargeable from the downtube and one is not rechargeable sits inside the display (or controller). If the battery inside the display is low it may cause the issue you just explained. I believe even the user manual from your bicycle tells it. If it is 2 years old then the battery inside the display (or controller) is likely on the dead row and it is a good idea to replace it.
I have been through the manual, no mention of a separate battery for the controller. It is powered by the main battery. However, there are some self diagnostics I can run through the controller to check the speed sensor, torque sensor, motor current etc... Next job
 

Steve b

Member
Apr 11, 2021
26
6
Peak District
Ran all the self-diagnostics as per the Yamaha PW-X2 manual (very useful), all good. Checked all the wires and connections to/from the motor - all good. Has to be the bike shop now...
 

Mitchb

Member
Nov 13, 2021
56
43
San Diego
I have a Yamaha with the same motor. Until you said you have not had any error codes I thought I had answer for you.

You might try this anyway. I was having shutdown problems and would get error code 71. Took it to the shop under warranty. They applied Dielectric grease to the connections between the motor and battery and I havent had a shutdown since.

Prior to that I secured the battery better by applying dense rubber pads between the battery and cover. Also raised the battery up a millimeter with 2 sided tape under the lower rubber piece, if you have something similar.
 

Steve b

Member
Apr 11, 2021
26
6
Peak District
I have a Yamaha with the same motor. Until you said you have not had any error codes I thought I had answer for you.

You might try this anyway. I was having shutdown problems and would get error code 71. Took it to the shop under warranty. They applied Dielectric grease to the connections between the motor and battery and I havent had a shutdown since.

Prior to that I secured the battery better by applying dense rubber pads between the battery and cover. Also raised the battery up a millimeter with 2 sided tape under the lower rubber piece, if you have something similar.
Very useful. I did have a similar problem with error code 71 about a year back. Solved it by cleaning everything with electrical cleaner. This time no error codes. But - where did they put the dielectric grease? On the copper prongs that go into the battery (probably not the fight technical term)? Also pushing the battery down toward the prongs may help. I'll try it. Just ran the self diagnostics again. Last 3 errors were 71, thought this was from last time I had problems, but hopefully its a simple connection issue. thanks very much for your help
 

SteveTTT

Member
Mar 15, 2022
47
35
Hampshire, UK
A similar problem with my Giant Trance (Yamaha motor, 800 miles, no error codes) was resolved under warranty by a new battery. LBS said it’s the battery management system, which I take to be battery firmware. A mate with an identical bike had the same issue.
 

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,283
4,780
Weymouth
Just to be clear about the use of dialecric grease, you do not put it on electrical contacts, for example the pins of a main battery to battery plug connector. Dialectric grease is a waterproof insulator so totally counter productive to use on electrical contacts. The problem many bikes experience especially when the battery to plug connector is either not very secure or not well protected ( most bikes with a cutaway downtube and plastic cover) is that female part of the connection can be widened by movement of the ( males) pins when the bike is being ridden or even by constant removal/replacement of the battery from the bike. The flat surface of the 2 parts of the connection can become wet and/or contaminated with dust or mud. Together those circumstances encourage arcing from one contact to another or even ontot he frame of the bike, which will reduce current flow or result in a complete short circuit. Carefully applying a smear of dialectric grease on the flat surfaces of the 2 parts of the connector whilst ensuring the contacts themselves remain clean, will help prevent that arcing. The contacts themselves are subject to oxidisation ( as is any contact carrying an electrical current) and the way to clean the contacts and largely prevent oxidisation is to clean them with electrical contact cleaner. Ensure the contacts are wiped dry or allow time for the contact cleaner to evaporate where that is not possible before using that connection. Treament 2 or 3 times a year is sufficient.
 

Steve b

Member
Apr 11, 2021
26
6
Peak District
Just to be clear about the use of dialecric grease, you do not put it on electrical contacts, for example the pins of a main battery to battery plug connector. Dialectric grease is a waterproof insulator so totally counter productive to use on electrical contacts. The problem many bikes experience especially when the battery to plug connector is either not very secure or not well protected ( most bikes with a cutaway downtube and plastic cover) is that female part of the connection can be widened by movement of the ( males) pins when the bike is being ridden or even by constant removal/replacement of the battery from the bike. The flat surface of the 2 parts of the connection can become wet and/or contaminated with dust or mud. Together those circumstances encourage arcing from one contact to another or even ontot he frame of the bike, which will reduce current flow or result in a complete short circuit. Carefully applying a smear of dialectric grease on the flat surfaces of the 2 parts of the connector whilst ensuring the contacts themselves remain clean, will help prevent that arcing. The contacts themselves are subject to oxidisation ( as is any contact carrying an electrical current) and the way to clean the contacts and largely prevent oxidisation is to clean them with electrical contact cleaner. Ensure the contacts are wiped dry or allow time for the contact cleaner to evaporate where that is not possible before using that connection. Treament 2 or 3 times a year is sufficient.
Great, thanks. I have cleaned the pins and slots on the battery with electrical contact cleaner quite regularly. I'll do it again and apply the grease as you suggest. Having borrowed a battery and ended up with the same problem if it is an electrical contact issue its likely to be the pins.
 

Steve b

Member
Apr 11, 2021
26
6
Peak District
A similar problem with my Giant Trance (Yamaha motor, 800 miles, no error codes) was resolved under warranty by a new battery. LBS said it’s the battery management system, which I take to be battery firmware. A mate with an identical bike had the same issue.
Thanks for your post. I borrowed a battery from a friend whose Haibike is working fine and the same power loss happened. So I don't think it's the battery. More likely the connection points. My bike has done 3000 rocky miles in the Peak District so it could be wear on the pins/battery connection points
 

Rickster

Well-known member
Subscriber
Feb 19, 2022
312
370
Ok BC Canada
I have been through the manual, no mention of a separate battery for the controller. It is powered by the main battery. However, there are some self diagnostics I can run through the controller to check the speed sensor, torque sensor, motor current etc... Next job
Steve, TQfreak is right about the second battery. No Yamaha display is powered by the main battery as far as I know. Could you take a picture of your controller to see what model you have ? There is a button battery in the back of the display as per TQfreak correctly mentioned.
 

Steve b

Member
Apr 11, 2021
26
6
Peak District
Steve, TQfreak is right about the second battery. No Yamaha display is powered by the main battery as far as I know. Could you take a picture of your controller to see what model you have ? There is a button battery in the back of the display as per TQfreak correctly mentioned.
Thanks again. Whilst I am no expert I don't think they are right. I have attached a photo of the back of the Controller, called Display A by Yamaha and also and extract from the tech manual. As far as I can tell there is no battery. Perhaps you have experience of different controllers/displays by Yamaha. IMG_0758.jpeg Screenshot 2023-01-01 at 20.22.15.png
 

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,283
4,780
Weymouth
At the bottom of your photo are 2 tiny screws holding what is most likely a cover for a button battery. The only other reason for that cover would be a USB port but according to your text above it does provide the facility of USB charging and usually a USB port would be only cover with a rubber bung.
 

Steve b

Member
Apr 11, 2021
26
6
Peak District
At the bottom of your photo are 2 tiny screws holding what is most likely a cover for a button battery. The only other reason for that cover would be a USB port but according to your text above it does provide the facility of USB charging and usually a USB port would be only cover with a rubber bung.
I assume the tiny screws take the back off the controller/display. No mention of any battery in the tech specs and the display only works when connected to the main battery. Why would it need another battery? I'll stick with the dielectric grease approach. Also I rode the bike for 40 minutes yesterday and it did not cut out. Surely if the button battery (if it exists) would cause problems straight away If I ever take the back off anything it never goes back correctly. .
 

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,283
4,780
Weymouth
No...they only allow the small cover plate to be removed. Assuming the controller has its own lithium battery its primary function is to send a voltage signal to the battery to switch on and only then will the screen turn on. For the sake of 30 seconds to remove that plate you will discover if there is a battery in there or not....................in fact there has to be a battery in there...........the only question is whether it is a stand alone battery or a rechargeable battery charged by the main battery once the system is switched on. Your experience of the bike switching off after you have been riding for a while is very unlikely to be any sort of bad contact problem.............that would be far more random in terms of timing. The symptoms you describe is logically more likely to be associated with loss of power due to a battery running below a critical level.
 

andyb2

Active member
Jan 10, 2020
176
251
somerset
On my Giant Trance with the yamaha motor, one of the connectors (I'm assuming it's for the controller cable) was broken, and the bike had similar symptoms as you (the bike shop had previously replaced the main power cable)

When I put the motor back in, I covered this with liquid electrical tape (but no grease) it was fine for a while, but it's now playing up again.

Power adaptor casing.jpg
 

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