How do I select a correct replacement motor controller?

[rotarypower101]

Don't know about that battery specifically.
Try pushing and holding the button in for a few seconds and see if the light shuts off.

That LED would cause an energy drain so plugging the battery for half an hour would be a good idea, but don't fully charge the battery then let it sit.

If you can check the voltage of the battery, it should be between 30% and 60% (I don't remember the actual voltage for that off hand?)

They are Lithium Ion, so probably around 3.7-3.8Vdc for storage voltage per cell, but I am not even sure what the S or P count of that pack is...it doesn't exactly have a label either... chinese hardware documentation, the bane of DIY repair.

While you are 100% correct, I dont have a easy way to drain it to storage voltage accurately, and until it is actually operational Im personally not too concerned about it. Thats how I recieved it, so dont feel too bad about any damage accrued while in my possession trying to fix this thing as a "Free Family Favor" Fortunatly she is a really good aunt, and has been a fantastic person to me my whole life despite being long distance, so if I can, I will fix it happily for her


I did try pressing it with diferent frequencies and holding, never saw any difference in operation.

 

[rotarypower101]

Yeah, that's probably it?

View attachment 168941

I don't have any personal experience with it, but my neighbor and others had e-bikes where they simply "unplugged the yellow wire" and their e-bikes went really really fast.

Then they cooked their SLA batteries or tore up their plastic gears in their motor.

The bikes went fast for a few months then they were discarded.

Maybe it was just the single yellow wire that was cut or removed from the plug?


You wouldn't have to deal with any of that mess with a clean install of a new controller and display.

Assuming that your motor isn't the problem of course.

Assuming that your motor isn't the problem of course.

Is there a quick and dirty protocol to test the motor?
I did test it the way the above video guy outlined, but because of the way the poles are wired, I believe a basic test can be deceiving?

Is there a easy way to definitively test the motors?
I have RC car sensored and sensorless brushless controllers, but barring that, I have no idea how a "normal person" would test that motor safely without potentially blowing up something else trying to find out it works/doesnt work...

 

[PCeBiker]

Any advice is welcomed!

Especially with all the little details I don't know anything about, and will certainly trip me up!

You can get a 3 pin julet connector for about $3 and cut off the one end and use it to splice into the three wire pedal sensor.


I've got one on the way as we speak.
As it turns out, you can run two throttles in tandem and I'm going to use the 3 pin extension to wire in a hall sensor throttle emulator.
Two batteries, two throttles, no pedaling.
That's just how I roll.

Getting the three wires correctly oriented is not as big a deal as the 8 pin motor cable, and you can blow s*it up in your motor if you power it up wired incorrectly.

The pedal sensor, brake switches and display are all powered by 5V signal power that normally can even be shorted without issue.
The brake switch just closes (or opens) the switch, "shorting" the 5 volts.

 

[PCeBiker]

Is there a easy way to definitively test the motors?

 

[PCeBiker]

It appears to use this specific variant of overmolded plug
View attachment 168942

That sure looks like the standard bafang high power motor plug to me, but I haven't seen one in person.

The only thing that I can think of is if the original ebike manufacturer had bafang mix up the pin configuration to make their motors proprietary, but your ebike looks pretty standard and it doesn't even have a pink battery wire, so you should be able to plug the motor cable directly into a KT controller.

 

[rotarypower101]

Its been a few months since I have tried to tackle this issue, but I believe I did check the motor pole wires by shorting poles like that , and did get the clear cogging and "regen braking" effect on each combination of the 3 power wires.

So I assumed because of the construction of the windings, they were far more robust than the fets in the controller? So just purely guessing the motor was fine, and just guessing I need to get a operational controller as a first step. As I have not been able to find any assistance or guidance, and that is where I was on this project so far.

 

[rotarypower101]

That sure looks like the standard bafang high power motor plug to me, but I haven't seen one in person.

The only thing that I can think of is if the original ebike manufacturer had bafang mix up the pin configuration to make their motors proprietary, but your ebike looks pretty standard and it doesn't even have a pink battery wire, so you should be able to plug the motor cable directly into a KT controller.

Its strange to me there is not a plug and play harness to adapt what I think are "old style" SM plugs to the waterproof ones they seem to be utilizing now? Why dont they have a plug and play option out there?

Or at least new old stock of controllers with those SM plugs and I assume older interface hardware?

Just strange to me that a direct 1:1 replacement cant be purchased on what I think is only a few years old bike.

Not a problem to adapt, just Really curious to me, and introduces possible errors and misinterpretations into the mix for hardware I don't know anything about.

 

[PCeBiker]

How "universal" and standardized are the protocols utilized on these ? I have a hunch based on these bikes origins...but maybe I will be surprised, and it wont be nearly as messy and obfuscated as my cynicism would lead me to believe.

A cadence sensor/PAS sensor/pedal sensor, is just a basic 3 wire hall sensor.

You just have to get the wires lined up correctly then set it up for forward or reverse.

If I find a SM plugged "old stock" controller will it likely plug right into the bafang motor and sensors, and be on its way no issues?

That's quite possible, but I'm not sure.

See how the motor cable connects inside the controller.
If it looks like the picture that harryS posted, then your motor cable should easily plug into an old-school controller.

harryS's picture is of the lower power connector plug, but you wouldn't be concerned about that part, just the connections at the controller.

I don't know what those connections would look like, but they may very well look like this SM connected, higher power KT controller?,..

If your controller looks like this, then you're in pretty good shape to easily install a KT controller.

Size may be an issue, but the different controller power options show all the measurements.

 

[PCeBiker]

Here's a blow up of the connectors from that last controller picture for reference,..

 

[rotarypower101]

If helpful at all to define operational compatibility, this is the pinout on the plugs for the controller that exist.

This controller has 8 SM plugs, 3 motor power outputs wires, and 2 battery power input wires.

To the best of my understanding:


Motor sensor is a 6 pin black plug with Red, black, yellow, green, blue, white

Just a guess but speed limiter plug that is looped back into itself? With white 5 pin plug has yellow with white stripe, green with white stripe, black with white stripe, red with white stripe, and unpopulate pin
Other side of speed limiter looped four pin black plug with yellow, black, Orange, burgundy
With the yellow with white stripe wire on the white 5 pin plug aligned with the Burgundy wire on the four pin black plug to the outside of the plug.


LCD display five pin black plug yellow, green with white stripe, black with white stripe, blue with white stripe, red with white stripe


PAS pedal assist system three wire black plug yellow with green stripe, black, red

Throttle three pin black plug black, blue, red

2 two pin black plugs for the brake sensors both black and grey pins


Do brake sensors Ever matter which is plugged into which brake for ANY reason?
There is no clear indication if there is?

 

[rotarypower101]

A cadence sensor/PAS sensor/pedal sensor, is just a basic 3 wire hall sensor.

You just have to get the wires lined up correctly then set it up for forward or reverse.

View attachment 168945





That's quite possible, but I'm not sure.

See how the motor cable connects inside the controller.
If it looks like the picture that harryS posted, then your motor cable should easily plug into an old-school controller.

harryS's picture is of the lower power connector plug, but you wouldn't be concerned about that part, just the connections at the controller.

I don't know what those connections would look like, but they may very well look like this SM connected, higher power KT controller?,..

View attachment 168946

If your controller looks like this, then you're in pretty good shape to easily install a KT controller.

Size may be an issue, but the different controller power options show all the measurements.

So these controllers are a little flexible with their programing and inputs they receive it appears?
Good , does it take any special equipment to be able to set these parameters? The simple fact is, im just looking to make this single bike operational, Not trying to get to far into the weeds if I can help it

See how the motor cable connects inside the controller.

If I understand/interpret what you are asking correctly, this specific controller is Completely potted!
Unless I completely destroy it, I dont think there is a easy way to see inside the controller.
Even replacing the fets would require destroying the original case I think. (which I can do if someone could offer their expertise on the exact fets to replace the originals with) Still hoping I can get help finding a replacement plug and play option for the reasons outlined above, minimizing my personal responsibility for changing/adapting/modifying anything that could fail subsequently with NO access to fix/repair some issue attributed to me.

The SM plugs on this controller are distinctly different from the Large white plugs on this controller pictured, Im not sure what those are called, but I believe they were contemporarily used with these SM plugs based on looking around for help before. They also possibly sapear asa alternative on this bikes controller schematic pictured above I believe?

Again I can adapt plugs, but hoping to find a direct replacement or plug and play adaptor if possible, understanding that May not be possible, but searching for that type of solution if it exists.

Grateful for any help, just so that clear!

 

[rotarypower101]

Here's a blow up of the connectors from that last controller picture for reference,..

View attachment 168948View attachment 168949View attachment 168950

I think I am interpreting what you are saying with a little more clarity now, so if I got one of the controllers pictured in this post, I could simply change the 6 pin motor sensor wires, and 5 pin display plugs, and hopefully that would be compatible?

That would be perfectly acceptable if I had a clear schematic to define each wire.

Hopefully this is what your inference is?

Still trying hard to keep up.

 

[harryS]

Brake sensors are two wires, normally open connection and are in parallel.

I'm glad you found a motor connector. That's a hex shaped Z916 connector, used for high current motors. Says the bike designer cares about the design, The smaller connectors would melt.

If you buy a replacement controller with a round motor connector, you will need it to be the larger hex connector, but they usually come with the territory when you go over 22A. Also an extension hex cable to reach the motor.

If you use a controller with flat connectors, you can reconnect the old cable with bullets and any 6 pin connector for the low power signals, Change the existing flat connectors to match your throttle, brake, PAS. Bafang motors put speed sensor inside the motor cable.

Personally, I like the controllers with molded connectors. It cleans up that rats nest of wires when they use a harness going up to the handlebars. Also, the flat connectors can get wet and cause problems. If you go that royte, buy the matching PAS sensor and the throttle at the same time. They're not expensive, and it saves a few hours of figuring out the pin-out on your existing sensors and then splicing in new round connectros.

 

[PCeBiker]

Motor sensor is a 6 pin black plug with Red, black, yellow, green, blue, white

Sounds right.

Red is +5V
Black is negative.
Yellow, Green and Blue are phase sensor wires.
White is speed sensor.

Just a guess but speed limiter plug that is looped back into itself? With white 5 pin plug has yellow with white stripe, green with white stripe, black with white stripe, red with white stripe, and unpopulate pin
Other side of speed limiter looped four pin black plug with yellow, black, Orange, burgundy
With the yellow with white stripe wire on the white 5 pin plug aligned with the Burgundy wire on the four pin black plug to the outside of the plug.

If that entire connector, both sides, only go into each other and then inside the controller and NOT out to any other connector, then it can be ignored.

LCD display five pin black plug yellow, green with white stripe, black with white stripe, blue with white stripe, red with white stripe

Sounds right,..

PAS pedal assist system three wire black plug yellow with green stripe, black, red

Black and Red are probably +5V and negative.
Yellow with green Stripe is most likely signal output.

Throttle three pin black plug black, blue, red

Red +5V
Black negative
Blue signal output
(probably)

2 two pin black plugs for the brake sensors both black and grey pins

Positive and negative.
Polarity doesn't matter.

Do brake sensors Ever matter which is plugged into which brake for ANY reason?

Nope,..
And you can connect both brake switches together in parallel if you only have one brake switch inputvon your controller.

 

[PCeBiker]

I'm going to let @harryS take over now.
I'm starting to go buggy from staring at my phone.

Converting everything to waterproof plugs is what I did, and what I'm familiar with.

I didn't like SM connectors and soldered my connections inside the controller.
My external connectors are all waterproof.

 

[PCeBiker]

Oh, one last thing,..

I ordered the KT controller that supports a headlight.

That comes with an 1T5 cable instead of an 1T4 cable, with the 5th being for lights.

That 1T5 cable comes with yellow/orange 3 pin connectors for the brake switches but only two of the pins are used.
The third pin is for a brake light if the e-bike is equipped.

The headlight equipped controller has a separate tiny daughter board to power the 48 volt headlight, but it's only capable of delivering 20 milliamps, about a 10 watt light.

If you hook up a more powerful headlight, then you'll pop the daughter board and have no headlight.

If that is a concern, then the 1T4 cable and controller are a better option with the simpler 2 pin brake switches, and a separate battery operated headlight.
Especially if your aunt doesn't ride at night.

 

[indianajo]

I do not splice wires except for dorman/3m/T&B/panduit/TEconn crimp terminals on the motor phase wires and battery wires. I use a screw terminal block for ring terminals, or connect .157" bullet connectors direct. Crimp connections made with a Klein or Ideal tool are reliable, as is the insulation on the US bullet connectors. The ****ese bullet connectors on the controllers, they require external tubing around them to not short to each other. I can still get controllers with the white rectangular blocks like post #28 and buy only those. I found a kit of those blocks and pins on ebay and solder the terminals on when necessary. The pins can be pushed out with a pick and re-arranged in any order. I ride in the rain and soldered splices out in never-never land are not reliable. Spliced wires on the frame could be yanked by my feet getting off, or by branches stacked on the bike lanes and sidewalks by homeowners. My harness is external since the electricity is a conversion of a pedal bike. Those white rectangular blocks are fine in the rain & snow at 48v. Sorry about the potting, that is a device to sell more controllers. Most of the controllers I've had the pcb slides out the end of the aluminum shell for repair. That is how I found out my first controller had no heat connection between the nfets and the pretty heat sink shell. The worst controller I had was a potted ASI from Lunabike, with pins on .5 mm spacing which shorted to each other in the rain and burnt that connector and the motor harness connector. Ride an ASI controller only in the Chilian Altacama desert where it has never rained. I had to go into the motor to replace the whole burnt harness for the hall effect sensors with the white blocks, which took 2 years to figure out how to get the case of the Mac off.
Don't know where pcebiker is finding those kt ads, certainly not on ebay. I've found the wiring of those round Juli connectors is rather random and avoid them totally. The last group of motors ($36 each) I bought the pins were intentionally made weird so nobody (but me) could use motors stolen from an Uber Jump. Motors had tamper proof screws & 7 sided nuts too, which I slotted removed & replaced. removed and replaced that Juli hall effect harness, too. I have a spare 1000 w DD motor in a wheel, which I abandoned due to the no power drag, so it is always ready to test controllers with. Just turn the bike upside down and install the working motor & wheel. If the phase order is wrong the wheel will roll backwards. If hall effect wires are wrong the motor will hum and not move. Or run for 10 seconds then quit.
Most of the scooter controllers have a "door switch" input which has to be given battery hot to make the controller move the motor. They also have a burglar alarm power connector which is always hot when the battery is plugged in. I run power from the burglar alarm connector to a toggle switch in a pill bottle, then back to the door switch input. That is the ignition switch, under my seat. The white block connector kit I got from ebay has 4 pin connectors of both sexes, too. Switch off, turning the throttle will not move the power wheel. The pill bottle strain relieves the wires, and provides a surface to hold the switch and screw it to an aluminum angle bracket. I once had a throttle which had a key switch from battery hot to a green wire, that could have been used to go to the door switch input of a scooter controller. When the ASI controller burnt that harness I lost the use of that throttle, which also had a useful voltmeter for the battery.
I determine PAS pickup, throttle input etc problems by keeping spares around. The 2018 ebikeling controller the brake wires stopped the motor by opening switches on the brake handles, but all more recent controllers the brake handles close a switch to cause the motor to stop.

 

[PCeBiker]

So these controllers are a little flexible with their programing and inputs they receive it appears?

Yes, if you get the 3 wires for pedal sensor oriented correctly, then the controller allows you to adjust for the different signals that would come from the pedal sensor.
The pedal sensor pulses a signal as the magnets rotate past the hall sensor.
Sensors have different amounts of magnets on the rotating wheel, and you want the ebike to power up when the pedals are moved forward but not when you move to pedals backwards.

The KT controller allows for a signal from any pedal sensor to be used by adjusting the input settings on your KT display. (But you want the KT LCD 3 or newer to have that adjustability in the display.)
Or, you could replace the the pedal sensor with a standard KT pedal sensor and it will just plug right into the controller and work.
But, replacing the pedal sensor most likely involves removing the crank arm to get it off and you'll need a crank arm puller.


The throttle can be easily and cheaply replaced and will plug right into the KT controller so you don't have to cut and splice wires and connectors from the old throttle.

It looks like your brake switches have an SM plug but it's easy to cut and splice the two wires into the connectors on the 4T1 cable.

Good , does it take any special equipment to be able to set these parameters?

No, just a voltmeter to check the wires to get the orientation correct.
But you can probably just trust the color code.
Red is positive, black negative, and the third wire is signal,.. Usually.

If I understand/interpret what you are asking correctly, this specific controller is Completely potted!

Oops, I meant at the controller, not in the controller.

Again I can adapt plugs, but hoping to find a direct replacement or plug and play adaptor if possible, understanding that May not be possible, but searching for that type of solution if it exists.

Being as your connectors won't plug into the standard SM version of the KT controller, then there is little advantage of using it other than having all the wires easily visible and identifiable.

Keep in mind that the 3 phase wires are ALWAYS matched to the 3 hal sensor wires.

Yellow with yellow
Green with green
And Blue with blue


Since the SM version of the KT controller isn't plug and play, then the waterproof plug version would be the easiest approach.

You just delete the old controller and the motor cable will just plug right in. (you may need an extension, as @harryS mentioned)

Then you've just got the PAS sensor, throttle, brake switches, and battery to connect.
The replacement display will just plug right in.


I think that finding an exact plug and play replacement controller will be difficult to find?
I wouldn't even know where to start looking?

Grateful for any help, just so that clear!

No problem.
This is kinda fun.

Here's a high power motor extension cable for reference,..

https://a.aliexpress.com/_m0LlDSC

Having the motor connections being plug and play makes things a lot easier to install.

 

[PCeBiker]

,.. Sorry about the potting, that is a device to sell more controllers. Most of the controllers I've had the pcb slides out the end of the aluminum shell for repair.

My original Das-Kit Controller was fully potted, and as much as that does hide the proprietary connections and software, it was as tough as nails, and fully waterproof.
It could be fully submerged in water. The box was solid cast aluminum and I could smash into a rock or curb and not damage it.
The build quality was way better and even the wires were thicker with better insulation on them.

The potting material also helps to dissipate heat. The heat sinks and mosfets could more easily transmit heat into the potting material than into the ambient air inside the box helping to keep everything in the box closer to the same temperature without any hot spots.

I ended up picking all the potting material out to investigate and found that the controller had a reverse firing order than a standard controller.

I think that is because the motor cable comes out the opposite side of the axle at the brake disk, not the freewheel, so the motor armature spins backwards?

 

[PCeBiker]

Is there a easy way to definitively test the motors?

If you end up with a new controller, and it comes time to test the operation, DON'T Give It Full Throttle !!

That's how you burn out a hal sensor in the motor if it's not connected properly.

Just give it a bit of throttle to see if the motor starts spinning or if it just makes weird noises and hums or clunks or something.


When it comes time to test the controller, just set the new controller beside the ebike, plug in the motor cable, new throttle, and connect the battery to test it.
No need to connect the PAS sensor until you get the motor operating properly.