Unexpected motor shutdowns

Dany68

New Member
Region
Europe
City
Muespach
Hello NCM community. So beautiful mountain walks, hence the interest in an electric bike. I bought myself an NCM Moscow Plus in 2021 and I was very happy with it, at the end of last year (around 2300 km) the engine started to cut out, first once or twice per outing to practically do stop and go after few weeks. I should point out that I always ride with assistance on 6 and that my average speed is 27 km/h so the engine is practically always stopped, and helps me "only" on climbs, and in this case its absence is makes you feel. It was explained to me that the fault as I described it came from the controller. Controller that I replaced and indeed the bike worked perfectly again for about 4 months (about 300 Km). Then the fault reappeared again, first the engine cut off as soon as I forced the pedals uphill and when I reached the top the engine started again, only to stop again and restart for no reason and no it doesn't matter when. The controller supplier does not want to exchange it for me under warranty and I do not want to buy a new one for 3 months. In addition, I bought an NCM Milano Plus for my wife, who following an accident can no longer use it (it had 350 km), so I put it up for sale recently and the buyer just told me that After doing 70 km the engine cut out from time to time. I'm afraid this is the start of the same breakdown. It same to be a problem of NCM bikes. Does anyone know what the defect is, and was able to repair it permanently? Is there any reason other than a controller fault? Thank you in advance for your answers and your help.
 
I’m not familiar with that bike but, on most displays, there are icons to indicate faults. If there are no faults listed (usually a letter and a number, ex, E30). Perhaps it is the normal operation of the brake sensor being induced unwillingly. A faulty brake sensor will cut out the motor. When your motor cuts out, is there any indicator on the display? Namely a brake icon? Though it is odd to have both bikes act like this.

What I would do first is, turn the bike on and activate the brake. Do you seen an icon? Then, whenever the motor cuts out, immediately check the display. Do you see the brake icon? Another test (if you are willing) would be to disconnect both brake sensors and ride the bike for a bit. Enough time for you to notice that the trouble is gone, or reappearing.

An important fact to know is, does the display turn off when the motor cuts out?
 
Hi Slaphappygamer, thank you for answering.
I've tried everything you suggest.
Disconnected the brake detectors, same fault ans No fault on the display, which continues to work perfectly (He doesn't stop).
he only indication is that the electrical aid level goes to zero, normal since the engine stops.

When the engine cuts off and does not restart, if I stop and press the starting aid (at minus for a few seconds) the display indicates 6Km/h, the engine starts and continues at 6Km/H, if I start pedaling the motor indicator goes up to 6 bars to immediately drop back to zero, and naturally the motor stops
 
You mention that you always ride around in PAS 6. As a test, what happens if you ride around in PAS 3, or 4? Does the motor still cut out?

I was thinking this might be heat related, but the fact that the bike worked for 4 months, after a controller replacement, tells me that may not be the case. I’m thinking a limit (of some sort) is being reached. Not a low voltage cutoff, since the display does not shutdown. Other than heat and low voltage cutoff, there are really only speed or power limits.

This may, or may not, be your issue. Ive had an uncomfortable experience with my bike. I had a low speed limit, but my bike can put out over 1000 watts. In the highest PAS, when the speed limit was reached, the motor stopped. Then when the speed fell below the limit, the motor would assist again until the speed limit was reached. This created an issue where the motor would “surge” while trying to maintain the speed limit. This was a predictable behavior and removing my speed limit resolved the issue.

The starting aid is a great troubleshooting tool. Thank you for mentioning. It’s good to know that the motor can still be engaged after the fault occurs. This is beginning to seem more like a power limit. I’d be hard pressed to believe you can reach a speed limit while going uphill as you mention in your first post.

I know @PCeBiker has a similar bike. Maybe he has other suggestions.
 
,.. I’m thinking a limit (of some sort) is being reached. Not a low voltage cutoff, since the display does not shutdown.

IIRC,..
When the low voltage cutoff is reached by the controller, it shuts down the motor but not the display, and you can still operate the headlight for about 2 hours after shutdown.

And, (IIRC, ) if it was voltage sag that shut down the controller, the power to the motor turns back on when the voltage bounces back after the load is removed.

@Dany68 what does your battery voltage and bar graph read just before you start going uphill, and what does it read when the motor shuts down?


Screenshot_20240602-120848_YouTube.jpg



Does it happen on a fully charged battery?

I'm thinking that your battery is old and is shutting down sooner?
Having the power to the motor turn on and off is normal operation when the battery is nearly empty.



,.. I should point out that I always ride with assistance on 6 and that my average speed is 27 km/h so the engine is practically always stopped, and helps me "only" on climbs,

If that is true, then your pedal effort would feel the same in PAS mode 6 as it does in PAS mode 0, going 27 kph on level ground,

,.. I bought an NCM Milano Plus for my wife, who following an accident can no longer use it (it had 350 km), so I put it up for sale recently and the buyer just told me that

Das-Kit says to charge the battery for two hours every 3 months during storage.

If this isn't done, the battery can become over discharged which can wreck a lithium battery. (the BMS is always drawing power)

After doing 70 km the engine cut out from time to time.

That's not a ridiculously bad range for a full charge, especially if your in PAS mode 6 and not pedaling very hard.

What size battery do you have?
Volts and Ah.

,.. Controller that I replaced and indeed the bike worked perfectly again for about 4 months (about 300 Km). Then the fault reappeared again,


That's the part that doesn't make sense to me.

Did you happen to start riding further after 4 months?
What did the battery bar graph and voltmeter say when it happened again?

Does it happen on a fully charged battery?
 
@Dany68
Your Moscow Plus is from 2021, so it might have the L6 or L7 display,..?

Screenshot_20240602-134813_DuckDuckGo.jpg
Screenshot_20240602-134636_DuckDuckGo.jpg




If your both your battery bar graph, and your power bar graph are showing 2 or 3 bars,. when you start up a hill, your power will surge which may cause the battery bar graph to drop to zero and your controller cuts power to the motor.


If this issue is happening on a fully charged battery, then something else is going on.
 
This is a link to the EBR review of the Moscow Plus,..


Screenshot_20240602-142813_DuckDuckGo.jpg




It lists the minimum range as 64 km with a maximum range of 153 km.

If you're getting 70 km on a charge, you're doing fine.
 
IIRC,..
When the low voltage cutoff is reached by the controller, it shuts down the motor but not the display, and you can still operate the headlight for about 2 hours after shutdown.
This is a very interesting fact. Riding around in the highest assist level will bring you to low voltage much sooner than say level 2 or 3. Thanks for your input. :)
 
This is what my owners manual says for my Das-Kit powered Et.Cycle T1000 with a 48V 21ah battery,..

20240506_184629.jpg



Contrary to popular belief, my manual says to run it dead every three months, so that's what I did when I got my ebike.

Keep in mind that the controller cuts out at 42 volts, which is not extremely low, and it saves a couple of volts to run your lights when you pedal home.

After my controller cut me out, I would pedal for a bit then the ebike would turn back on, but as soon as I would hit the throttle without pedaling, the voltage would drop and it would cut out again.



After I installed the KT controller and display, the same thing would happen, but I would have to turn the display off then on again to restart the motor.

The one time that I ran out of battery, I ended up restarting it several times, and each time I had to pedal harder to get up to speed before I activated the throttle to prevent the voltage sag that would cut me out again.

I could have entered my settings and turned down my cut-off voltage, but I didn't want to fry my battery.
I set my cutoff voltage to 41.5 volts to help protect my battery. I could have turned it down to 38 volts, but I didn't want to completely drain my battery, and I didn't have too far to go to get back home.
It's good to know I've got a few volts of reserve to save for an emergency.


Screenshot_20240602-165132_Adobe Acrobat.jpg
 
After reading thru all this - symptoms, etc., my (un)professional opinion is that you are reaching LVC on the battery or controller which is causing the shutdowns. This could be due to a worn out or defective battery. I'm not sure why one would ride in PAS 6 all the time.At that level, you are making little, if any contribution by pedaling and might as well be running under full throttle. Also this will draw more current which can cause the voltage sag in a weak battery,
 
Thank you all for the help you are trying to give me, it’s very nice.
After reading your answers, I realize that I must not have been very clear in my explanation.
So I start again, I ride with electric assistance on 6 but as my average speed is 27Km/H, I practically never use the engine (the bars on the display are actually at zero, yes it's true PceBiker I could ride in PAS 0, but as the region is hilly I prefer to have help immediately when my cruising speed drops) and as a result I only discharge the battery slightly during my outings.

I put a rotation detector on the pedals and I try to roll with calf force between 60 and 70 UPM.
The engine only engages on climbs, and I play with the manual gears to keep my speed.
For the moment my outings are limited to 40/50 km and I use around 1 to 1.5 volts of the charge, per outing.

Now to answer your questions, I have a European Das-Kit C7 display (electrical assistance limited to 25 Km/H)
I have the same problem with all PAS from 1 to 6.
Regarding the fact of having reached a limit this is not the case, since it happens at any time, at any speed, or uphill or on the flat.
So of course and as said, as on the flat I drive faster than the electric aid, I don't even notice the problem, it's only when I arrive on climbs that I realize that either the engine is not does not engage or that it cuts off mid-rise.
I don't think there is a speed limit either (where can I see the setting), the other day I was going up a slope with the engine assist, suddenly the engine cut out, I managed to climb by forcing and changing chainrings, with a speed of 9Km/h, while the PAS was on 6 (25Km/h), if the bike works normally, with the PAS on 6, I am still around a minimum of 22 km/h.
Concerning the display during the problem, I have to check, but the only change I remember are the bars at the top left symbolizing the electrical assistance (they drop to zero to go up to the maximum)
Concerning the battery, this happens whether it is just charged or after several outings (as said I do not use the battery much) but as my wife had the Milano Plus, I tried with its battery and I had the same problem.

Concerning my wife's bike, the new buyer did not do a 70 km ride, but several rides of 70 km in total (recharging in the meantime) and on the last ride he had the problem of the engine cutting out.

Concerning the battery it is a 48 Volt 16 Ah 768 wh, on the Moscow and on the MilanoNo

I didn't drive further after 4 months.
The whole error doesn't make sense to me.
At first the engine cut off unexpectedly once or twice during a 40 km outing, then it became more frequent, until it happened almost all the time (but not regularly).
Then I changed the controller and the bike worked correctly again with the motor which engaged immediately when it should and cut off once the speed (selected with PAS) was reached.
And this for about 4 months, and suddenly the fault reappeared, the engine cut off on climbs (normal since on the flat it is practically always off) then the engine started again when I arrived at the top of the hill. Then on the following outings (always around 40 km) the breakdowns became more frequent and also on flat ground (I drove more slowly to see).
So no change in use, battery still sufficiently charged and no other symptoms. And yes this also happens with a fully charged battery and on flat ground (so without much effort).
So we in Europe do not have the right to the accelerator, we must pedal so that the engine has the right to assist us.
How to adjust the cut-off voltage?
I have attached the photo of my display when it is switched on, so that you can see all the symbols, but of course I do not have an error message (number) when the fault occurs.

Two points for my information, what does IIRC mean and what does LVC mean.

Thank you again for your time and contribution
 

Attachments

  • Das-Kit C7.jpg
    Das-Kit C7.jpg
    287.8 KB · Views: 28
OK, you've got a different problem that I didn't encounter.
I only used my ebike for about 400 km and 3-4 months before I replaced the controller and display with a KT controller and display.
I didn't have the problem you are having.

Two points for my information, what does IIRC mean and what does LVC mean.

IIRC stands for "If I recall correctly".
I changed my controller and display over a year ago, and I forgot a lot of the details of how it operates.
LVC stands for "Lov voltage cutoff", and that's the voltage that either the battery or controller shuts down the battery.
Your ebike is shutting down with an almost fully charged battery, so it's not the LVC that is shutting you down.

Thank you again for your time and contribution


Here is another thread with what appears to be the exact same problem that you are having.



It looks like the controller is faulty and that a new controller doesn't fix the problem, or it doesn't last.

I don't know what to say?
 
LVC stands for "Lov voltage cutoff", and that's the voltage that either the battery or controller shuts down the battery.
Your ebike is shutting down with an almost fully charged battery, so it's not the LVC that is shutting you down.
I too am somewhat perplexed. It still smells a bit like battery to me. A battery can fully charge and show the 54.6V and still have some weak or defective cells. Applying enough current can cause the voltage to sag enough to trigger LVC.

A couple of thoughts (and I'm grasping here)
  1. If you can lay your hands on a fresh battery try it and see if the problem persists
  2. You can somewhat test the health of your battery off the bike, by fulling charging it, putting a wattmeter inline between the battery and a load (heater, etc - something that will draw at least 5 amps), and fully discharging. If the resultant watt-hours used is significantly less than the rated capacity, the battery is suspect.
 
I too am somewhat perplexed. It still smells a bit like battery to me. A battery can fully charge and show the 54.6V and still have some weak or defective cells. Applying enough current can cause the voltage to sag enough to trigger LVC.

A couple of thoughts (and I'm grasping here)
  1. If you can lay your hands on a fresh battery try it and see if the problem persists
  2. You can somewhat test the health of your battery off the bike, by fulling charging it, putting a wattmeter inline between the battery and a load (heater, etc - something that will draw at least 5 amps), and fully discharging. If the resultant watt-hours used is significantly less than the rated capacity, the battery is suspect.

I agree,. or maybe a bad connection on the battery terminals, or maybe a bad connection between the display and controller?
But, why would a new controller fix the problem but only last for 4 months?

The only way that makes sense is a bad controller maybe with a software glitch?

Just an FYI (for your information).
As far as I understand it, the CT5-I5 is the same controller for all the different markets.
The power and speed are limited by the display, with a different version for the European, Canadian and American markets.

The European version is limited to 15 amps max, and 25 kph.
The Canadian version is limited to 18 amps max and 32 kph.
And the American version is limited to 21 amps and 48 kph.
 
Hello everyone,
as said I tried with the battery of my wife's bike and I have the same problem, so I think is not the battery.

"The only way that makes sense is a bad controller maybe with a software glitch?"
What do you mean with this PCeBiker?
Is the software in the controller or in the display?
What should I change?

What also bothers me is that by changing the controller it worked for 4 months and I wouldn't want to change the controller every 4 months...
 
"The only way that makes sense is a bad controller maybe with a software glitch?"
What do you mean with this PCeBiker?
Is the software in the controller or in the display?
What should I change?

I was just guessing as to what the problem could be.
The problem appears to be in the controller because your display has worked with all your controllers.

What also bothers me is that by changing the controller it worked for 4 months and I wouldn't want to change the controller every 4 months...

Changing the controller again will probably fix the problem but I have no idea why it only lasts for 4 months.

I know that Amego in Canada sells the controller.
Perhaps a Controller from them is more reliable? But that's a complete guess.

Someone from the UK has recently purchased one, and they do ship to the UK.




If replacing your controller has fixed the problem before, then it will most likely fix the problem again.
Maybe a controller from a different source will be more reliable?
 
Last edited:
Is the software in the controller or in the display?
What should I change?

I'm not positive because the software is proprietary and I couldn't find much information about it.

Controller that I replaced and indeed the bike worked perfectly again for about 4 months (about 300 Km). Then the fault reappeared again,

That's the thing?
Why would it work perfectly for 4 months then fault again?
So I would assume it's the controller again.


However,..
As far as I know (after installing my KT controller and display)



There is both 48V and 5V fed to the display.
The 5V powers the display, then the display analyses the 48V (~40V-54.6V) and shows it on the screen as a numerical voltage and a bar graph.

I'm pretty sure that the cable running to the display has 9 wires in it, and one of those wires is +48V.
If the connection of that +48V wire is lost, then the display would read 0 volts and the controller would shut down, but the display would still be on because it is powered by the +5V.

Perhaps plugging the display connector into the new controller got the connection back in the plug, and it worked for a few months until the connection failed again?

Maybe unplug your display connector and look for bent pins or corrosion.

So maybe a new display, with a new plug will fix your problem?


Remember, this is all just speculation on my part, but maybe a new display is your answer?

I know that Amego is Toronto will assemble, setup and test an ebike for an extra fee.
During that setup, they disconnect every plug and put dielectric grease on the connection.
That Really helps maintain a good connection and prevents corrosion, and it Really helps to prevent electrical Gremlins from haunting your ebike.

One of the first things I did when I assembled my bike-in-a-box, was to disconnect all the connectors and grease them up good!
 
Thanks guys, I'll check this asap, lots of work over the next few days and get back to you ASAP
 
Almost the same problem on my Bafang B001, dies (turns off, all electrics) after 1-2 miles, you then turn battery off, back on switch on and go for about 20 yards then repeat, going in THIS Thursday, could be controller
 
Hello guys I'm back, so I received a new controller (under warranty) and installed it.
The bike is working perfectly again, hopefully it will last.

Before assembling the controller I examined it carefully and although it is cast in resin, there are several small holes (going through to the plate), I wonder if this is not the reason for the problems .
Especially since the same holes appear on the other 2 controllers.

And now my wife's bike (NCM Milano Plus) which only has 350 km (but 3 years old) is starting to have the same symptoms (engine does not engage when it should).

I had checked the connectors and everything seemed perfect.

I thought about putting conductive grease in the connectors but I'm afraid it might cause a short circuit?

PCeBiker, you offered me your C7 display but won't there be a problem with my bike given that the European display limits it to 15 amps while yours will limit it to 18 amps (my battery is only 16 amps?
 

Attachments

  • 20240613_083011.jpg
    20240613_083011.jpg
    286.7 KB · Views: 29
  • 20240613_083049.jpg
    20240613_083049.jpg
    346.4 KB · Views: 32
  • 20240613_083104.jpg
    20240613_083104.jpg
    345.7 KB · Views: 35
  • 20240613_083137.jpg
    20240613_083137.jpg
    277.4 KB · Views: 30
  • 20240613_083146.jpg
    20240613_083146.jpg
    291.3 KB · Views: 28
Back