M Class display

[Joodeee]

I am looking for a replacement display. Possibly from an unused bike? AR could not locate an original replacement and so sent me something off market which did not work. I'm hoping this is the issue with the fact that my bike's motor cuts out randomly, usually in higher PAS levels, going up hills and/or pedaling hard. Otherwise my bike is perfect still at 2.5 years and 3500 miles.

 

[RollinRollinRollin]

I have to ask...I assume AR checked the brake cut-out switch, correct?

 

[Joodeee]

I don't know the answer to that. We got a new motor from AR, did some Zoom calls...then took the bike to a local ebike mechanic, who had it for over 3 months. They communicated with AR, got a new display and tree cable. The new display did not work at all for them, saying they couldn't get it to go over 15mph. I picked it up and it ran fine for 2 days (on old display), all PAS and gear levels, no problem getting up to speed. And then on a longer ride, at mile 13, the motor cut out again. On the 13-mile ride home it cut out 2 more times. Would have been more but I babied it, not going over PAS 3 and keeping heavy pressure off the pedals as much as possible. We are stumped.

 

[Slaphappygamer]

Not sure about the speed limit. Could be related to display settings/limit.

The motor cut out, seems like that might related to the battery. Do you have a volt meter on your display? Under heavy load, you might see 4 volt drop. If you have a bad cell, then the drop may be more sever. This would trip the low voltage cut off and the bike will shut off.

Is it just the motor that shuts down, or the entire bike?

 

[Joodeee]

The entire bike shuts down but I can turn it off (on battery) and back on, whereupon I can ride until the same thing happens. I have tried the battery from my friends' identical bike and believe the batteries are fine. Unfortunately, I rode my friends bike a couple days ago and the same thing happened for the first time.

 

[EMGX]

Were you riding your friend's bike with your battery or theirs when the fault occurred? When your friend rides their bike do they have the same issue? How about if your friend rides your bike with your battery, same issue?

 

[Joodeee]

We've done it all. The friend barely rides his...he bought it from my bf last year but probably never put more than 5 miles on at a time so it never happened to him. When it happened while I was riding his bike the other day, it was particularly disappointing as I been going to buy his and then have both bikes for parts and hope to get a couple more years. From the beginning, we had changed batteries back and forth and when mine started acting up, I had borrowed his friends bike and tried it with both batteries...that was not the problem. My bf, who is much more bike mechanic savvy, has ridden mine with the same problems.

Even tho my new bike is more powerful and goes longer distances, the M bike is my favorite for comfort and ease as it is mid-drive with torque sensor. My new bike is mid-drive but with cadence and I found I far prefer the torque. My hope was to leave one bike at my bf's and one at home as we live an hour apart and ride both places...a lot.

 

[EMGX]

Strange that two bikes exhibit the same fault unless it is normal battery voltage slump related. It does sort of sound like the battery voltage is dropping below the low voltage cut out when you are on longer rides using more power and the bike works again after the battery is rested a bit when you turn the bike off then turn it on again then ridden with less assist. See slaphappygamer post.

PS
when the bike shop installed the replacement display and were limited to 15mph that might have been due to the replacement display being programmed to limit to 15mph as is the requirement in some countries and not a malfunction. Again see slaphappygamer post.

 

[Slaphappygamer]

I'm not familiar with that bike. For both bikes to have similar issues with both batteries. Could there be a heat issue? Strange it would happen with both bikes. If you can, feel the motor, motor wire, or controller after the shutdown. Are they hot? Could be maybe the controller, or motor, reach max heat and shutdown. There are really only a few reasons the bike would completely shutoff, but then come back on. Battery issue, heat, or the random, just barely loose, wire that looses connection under heavy vibration, but then reconnects itself. Most likely not the latter but, it could happen. Maybe @AHicks, @PCeBiker, or @PedalUma have other ideas?

 

[PCeBiker]

The entire bike shuts down but I can turn it off (on battery) and back on, whereupon I can ride until the same thing happens. I have tried the battery from my friends' identical bike and believe the batteries are fine.

The same thing happens on my e-bike when the battery is getting low.
The first few times my controller cuts me out, then finally the battery's BMS shuts me down and I can't restart the e-bike.

The motor cut out, seems like that might related to the battery. Do you have a volt meter on your display? Under heavy load, you might see 4 volt drop. If you have a bad cell, then the drop may be more sever. This would trip the low voltage cut off and the bike will shut off.

That's what I think is happening.

See if you can get the voltmeter to show the voltage if your display has one.

How many Volts/Amp hours/Watt hours is your battery?
The smaller the battery, the greater the voltage sag and the sooner it will shut down on you.

 

[Joodeee]

Ok, I will chk these things asap and post result. However, I'm away from my bike for about 10 days now. Crossed fingers for success! I am sharing this with my bf (where my bike is). Thank you all for your help and stay tuned!

 

[Joodeee]

I'm back working on my bike and hoping for solutions. I've put the new display on from AR but it is not functioning properly (also shows a flashing motor icon). Have sent a video of the screen to AR to see if there are any settings to be changed. My display does not show the voltage other than to be sure it is set to the correct 48 volt. I have tried 2 different batteries with the same motor cutout result. Again, I am able to restart it immediately after
My battery is 12 Amp hours, 576 watt hours.