Can a hub motor be incompatible with a controller?

[rick_p]

Having a hub motor be incompatible with a controller goes against my limited knowledge about the technology, but I'm not sure what else would cause this behavior.

Here's the situation, I have a bike that was cobbled together using used parts, and it works just fine, I have well over a thousand miles on it, but I picked up another (used) rear wheel the same size as mine with the same 9-pin Juliet waterproof cable, and just wanted to test it to make sure it works and keep it around for a spare. So, I put it on my bike for the test, and the bike turned on just fine, the display reported no errors, but when I went for a test ride, the wheel only works using the throttle, it doesn't respond at all to PAS, and the speedometer is way off too. I put my old wheel back on and everything is fine, any ideas what might cause this strange behavior?

Thanks in advance.

 

[docw009]

The difference in indicated speed could be due to LCD settings for the magnet/gearing or differences in pulses/rpm from any discrete speed sensor in the motors.

I don't see how the PAS is affected by the motor, if the PAS sensor is on the pedal axles. If it were on the motor axle as is done with some commercial ebikes, but not something you would expect on a bike made with used parts, then I would say the second motor is missing the magnets that activate that kind of sensor.

 

[rick_p]

The difference in indicated speed could be due to LCD settings for the magnet/gearing or differences in pulses/rpm from any discrete speed sensor in the motors.

This makes a lot of sense, and I'm hoping it is not related to the lack of response to PAS.

I don't see how the PAS is affected by the motor, if the PAS sensor is on the pedal axles. If it were on the motor axle as is done with some commercial ebikes, but not something you would expect on a bike made with used parts, then I would say the second motor is missing the magnets that activate that kind of sensor.

The PAS is on the pedal axis, it's one of those plastic rings with magnets on it that is pressed unto the bottom bracket with the sensor right on the inside of it. I'm happy to get confirmation that my understanding of how these things work is consistent with yours. It is very strange indeed. Not having PAS wouldn't bother me all that much, except this controller is one that limits the throttle speed to 20mph, but allows PAS to go to 24mph.

 

[rick_p]

It turns out that PAS was working on the first test ride, but it was working at such a low level I didn’t feel or hear it. I figured this out when I tested it on a stand instead of riding it. It is still very glitchy in that it doesn’t respond to changes in the PAS level, and the speedometer is still wrong, but I also tried changing the configuration settings in the display and it responded slightly to the changes. In the end, I’m not really any closer to having a fully working spare, but it’s interesting that it’s not completely unresponsive to the PAS sensor. I’m not sure what else to try.

 

[E-HP]

Are both motors direct drive or geared? Which controller are you using?

 

[rick_p]

Are both motors direct drive or geared? Which controller are you using?

Both motors are geared, one is branded Pedigo, the other eMotion.
The Pedigo branded one works correctly with the controller and display, the eMotion one does not.
I didn't notice until now that both wheels have similar model numbers painted on the hub motors, or they start out similar anyway.

Pedigo - M155 CN3612. (48V)
eMotion - M155 CN3617. (48V) 1712BH0451 (U) EM50048H28 MTOHPM155CN038K

The controller is a Lishui from 2018, my searches for the exact model number don't return anything.
Model: LSW1017-9-2F X1812082525
Rated voltage: 48V
Maximum current: 20A
Rated current: 10A
Low voltage protection: 39V
Throttle adjustment voltage: 1.2v - 4.4v

 

[d8veh]

First, you must set the LCD with the correct number of magnets for the motor speed sensor. My guess is that the first motor has 1 magnet and the second 6 magnets. If you have a max speed set for the PAS, the incorrectly calculated speed is probably too high, so power is being cut off at a very low actual speed.

Get manual for the LCD, find the setting and make it correct. Alternatively, you can open the motor and remove 5 magnets.

 

[E-HP]

First, you must set the LCD with the correct number of magnets for the motor speed sensor. My guess is that the first motor has 1 magnet and the second 6 magnets. If you have a max speed set for the PAS, the incorrectly calculated speed is probably too high, so power is being cut off at a very low actual speed.

Get manual for the LCD, find the setting and make it correct. Alternatively, you can open the motor and remove 5 magnets.

There's a post on another forum that disassembles the motor and you can clearly see the 6 magnets on the inside of the cover for the speed sensor. I looked at a few manuals for Lishui compatible displays, but the ones I looked at didn't have a magnet count setting for speed (only for PAS), so it would be helpful if the OP would provide the display model number.

 

[rick_p]

First, you must set the LCD with the correct number of magnets for the motor speed sensor. My guess is that the first motor has 1 magnet and the second 6 magnets. If you have a max speed set for the PAS, the incorrectly calculated speed is probably too high, so power is being cut off at a very low actual speed.

Get manual for the LCD, find the setting and make it correct. Alternatively, you can open the motor and remove 5 magnets.

The display is a KD58C, the early model with the M on the mode button opposed to the power symbol on the later model. Going though the settings per the manual was the first thing I tried before posting here. There is a speed setting for the magnets for the motor speed sensor, the default is 1 and it cannot be changed. I don’t actually care about the speedometer, but I do care about PAS. There is a setting for the number of magnets on the PAS sensor, the default is 12 and cannot be changed. There isn’t a max speed setting for PAS, but you can set the max speed, which I have set at the max allowed 40kph. You can also set the percentage of power for each PAS level, I have it set to five levels with 20% at level one and increasing 20% with each level, except level five, which I set to 95% instead of 100%.

There's a post on another forum that disassembles the motor and you can clearly see the 6 magnets on the inside of the cover for the speed sensor. I looked at a few manuals for Lishui compatible displays, but the ones I looked at didn't have a magnet count setting for speed (only for PAS), so it would be helpful if the OP would provide the display model number.

As noted above, it’s a KD58C, and the display and controller are a matched set, they came together on a beach cruiser style bike, the wheel on the original bike was a direct drive wheel that got destroyed. I’m not sure why they fixed the speed magnet count at 1 but I’m sure they had a reason.

I’m surprised no one finds it significant that the two wheels have similar model numbers, in my mind it makes me think if one works correctly, the other should too.

 

[d8veh]

The display is a KD58C, the early model with the M on the mode button opposed to the power symbol on the later model. Going though the settings per the manual was the first thing I tried before posting here. There is a speed setting for the magnets for the motor speed sensor, the default is 1 and it cannot be changed. I don’t actually care about the speedometer, but I do care about PAS. There is a setting for the number of magnets on the PAS sensor, the default is 12 and cannot be changed. There isn’t a max speed setting for PAS, but you can set the max speed, which I have set at the max allowed 40kph. You can also set the percentage of power for each PAS level, I have it set to five levels with 20% at level one and increasing 20% with each level, except level five, which I set to 95% instead of 100%.

As noted above, it’s a KD58C, and the display and controller are a matched set, they came together on a beach cruiser style bike, the wheel on the original bike was a direct drive wheel that got destroyed. I’m not sure why they fixed the speed magnet count at 1 but I’m sure they had a reason.

I’m surprised no one finds it significant that the two wheels have similar model numbers, in my mind it makes me think if one works correctly, the other should too.

Your settings are locked for a specific application. It might not be compatible with yours.

 

[ml4050]

I believe M155 CN3617 is a DAPU motor (Japan).

Dapu｜bicycle drive systems

Dapu delivers precision bicycle drive systems that perform at the top of their game. Enjoy the ultimate freedom to go wherever you want, whenever you want.

www.dapumotors.com

 

[rick_p]

Your settings are locked for a specific application. It might not be compatible with yours.

This does seem likely, and I guess I just got lucky that it worked so well with the first wheel. I wonder what my chances are of this wheel working with a generic controller and display.

 

[rick_p]

I believe M155 CN3617 is a DAPU motor (Japan).

Dapu｜bicycle drive systems

Dapu delivers precision bicycle drive systems that perform at the top of their game. Enjoy the ultimate freedom to go wherever you want, whenever you want.

www.dapumotors.com

Those do look exactly like mine, but since the model numbers don’t match exactly, mine must be custom an application like d8veh said.