Controller replacement question

[Stefancos]

Greetings.

About two years ago I converted my regular mountainbike into an ebike with a front wheel motor (36 volt, 250 watt), controller, pedal assist and thumb throttle and ran it for abu5 1,5 years without any hassle.

However a few months ago it developed a fault where the motor essentially began to "seize" and resist whenever power was applied to it, either via the pedal assist or thumb throttle.

This week I've been trying to find out if the problem is either with the motor itself or the controller. I used the controller to connect a week I borrowed from someone to fine that it had similar issues of seeming to resist when switched on. Which would indicate there an issue with the controller.

The problem is that I can't find a replacement for it. Googling the model number gets me many options of controller that are similar, but not identical.

I have another controller, however that has a hall sensor that consists of 6 wires, while the wheel I have only has 5 wires. So I don't know if they aye compatible.

Both hall sensors have yellow/green/black/red/blue wires. My spare controller also has a white wire.

My questions.
Is there any way to use my spare controller despite the hall sensor mismatch?
If not, is can anyone help me to determine what a suitable replacement controller would be?

Thanks in advance.

Stefan

 

[Stefancos]

Hello.

I have a functiong ebike motor, a front wheel 36v, 250 watt, brushless, brand = Trotter.
It has 3 phase wires, Blue/Yellow/Green, and 5 hall sensor wires (Black, Red, Blue, Green, Yellow)

I'm looking for a controller for it.

Anyone have any links, tips, suggestions?

Regards.

Stefan

 

[markz]

https://evfittinggreentime.aliexpress.com/store/group/E-bike-Brushless-Controller/313864_211689768.html?spm=a2g0o.store_home.pcShopHead_11248317.1_0

 

[docw009]

The white on the 6 pin Hall connector is to support an internal speed senor from the motor. Your motor doesn't have an internal sensor if it only had 5 wires. Thats OK. If your original controller and LCD showed the speed, then there must be a external sensor on the front wheel.

When you hook up the brainstorn controller and its LCD display, it will expect that white wire to be there. By the way, I also have that same controller in my spares box. The motor will run, and the controller can figure the speed via the Hall sensors, but when you start coasting, the speed will go to zero because the controller cannot see a speed sensor,. You can fix that by wiring an external speed sensor to the controller. You can get power from the red and black wires in the Hall connector, or from the power wires in the PAS connector. The output of the wheel sensor will go to the white wire.

I just did this when salt destroyed the internal speed sensor in one of my hub motors. I finally got around to installing an external sensor on the wheel, and doing the above wires. My only bug is the external sensor is quite noisy. The speed sometimes jumps around under power, but is steady when coasting.

 

[Stefancos]

Interesting, thank you. Could you tell me what type of speed sensor works with the Brainpower controller?

Stefan

 

[amberwolf]

However a few months ago it developed a fault where the motor essentially began to "seize" and resist whenever power was applied to it, either via the pedal assist or thumb throttle.

This week I've been trying to find out if the problem is either with the motor itself or the controller. I used the controller to connect a week I borrowed from someone to fine that it had similar issues of seeming to resist when switched on. Which would indicate there an issue with the controller.

If a second controller shows the same problem as the first, then the problem is not with the controller, The problem is the motor. (assuming that both controllers had the correct phase/hall wiring combination connected to the motor, or that the self-learn function correctly automatched them).


If the motor, not connected to a controller at all, does it roll smoothly without problems? If so, then the phase wires and windings are probably fine.

But the hall sensors or wires to them or the connector could have problems.

Was the bike ever crashed? Or fall over on it's side, or get wet? Or was the wheel taken off to change a tire or fix a flat, etc?

Any of those things could ahve damaged the wires where they exit the axle, or caused connection problems at the connector itself.

I would recommend closely examining the entire cable from connector to axle exit, and if any damage is found, check any exposed wires, etc. for shorts or breaks.

If none is found, then you can use a multimeter to test the halls while plugged into a controller. We can tell you how to do that if you get this far.

 

[Stefancos]

Perhaps i wasnt clear.

I deduced the problem lies with the controller because I used a different ebike wheel I borrowed and it gave the same problem when I connected my controller to it.

The second controller is one I bought on a whim a year ago but didnt use because the hall sensor on it turned out to have 6 wires instead of 6.
I did hook up both ebike wheels to is and in both cases the motor works, though only in a single speed.

this leads me to believe I have one controller thats damaged, and one controller thats just not compatible. Does that sound reasonable?

 

[amberwolf]

Perhaps i wasnt clear.

I deduced the problem lies with the controller because I used a different ebike wheel I borrowed and it gave the same problem when I connected my controller to it.

Ah, well, that's not what you said, so that's why I posted what I did.

I used the controller to connect a week I borrowed from someone to fine that it had similar issues of seeming to resist when switched on.

reads as if you borrowed a controller for a week, implying that it's a second controller, not a second wheel/motor.

So I presume "week" was supposed to be "wheel", which makes more sense of the situation.

The second controller is one I bought on a whim a year ago but didnt use because the hall sensor on it turned out to have 6 wires instead of 6.
I did hook up both ebike wheels to is and in both cases the motor works, though only in a single speed.

this leads me to believe I have one controller thats damaged, and one controller thats just not compatible. Does that sound reasonable?

Yes.

FWIW, the second controller is perfectly compatible with the motor itself, if it works while riding it. If it doesn't have the same features your other one did.

Did your original controller display the speed correctly, with only the wiring to the motor? Or does it have an external speed sensor and magnet on a wheel?

If the former, then you should be able to connect the white wire to any of the hall signal wires (green, blue, yelllow), but the speed will probably read way higher than it is supposed to. If the display has settings for number of poles in the motor, you can fix that there, by dividing the speed number you actually get from what you would normally have gotten when riding at the same speed (guesstimating), and using the result as the number of poles.

If it doesn't have that option, you'd have to use an external wheel sensor and magnet (ebikes.ca carries them, but shipping costs a lot for a tiny thing, so it is probably cheaper to locally find a really cheap bike computer and cut it's wheel sensor off and use that instead).

 

[docw009]

Interesting, thank you. Could you tell me what type of speed sensor works with the Brainpower controller?

Stefan

First, tell us if your original KT controller used an LCD that displays speed. If it does, then locate the external speed sensor that must be on the front wheel.

We're giving this sensor too much credit. It's just an RPM counter. Has a circuit that flips the output between 5 volts and ground, every time the magnet on the wheel passes it. The LCD has to know the wheel diameter so it can compute the speed.

If your original KT display didn't show the speed, then there is no speed sensor and you buy one for the brainstorm unit. Amberwold's suggestion for a bike computer sensor will work. There are also a few speed sensors available for quicker delivery on amazon. A PAS sensor will work too.

 

[Stefancos]

FWIW, the second controller is perfectly compatible with the motor itself, if it works while riding it. If it doesn't have the same features your other one did.

Did your original controller display the speed correctly, with only the wiring to the motor? Or does it have an external speed sensor and magnet on a wheel?

First, tell us if your original KT controller used an LCD that displays speed. If it does, then locate the external speed sensor that must be on the front wheel.

The original KT Controller came with a LED display. The KT Led 880, so no speed display.

The Brainpower controller came with an S886 LCD display, which when running connected shows an E10 error.
The Brainpower controller/S886 display only turns the wheel when hooked up and activated, there's no speed control, nor does the peddle assist or thumb throttle do anything. Which is why I didnt do anything with it originally.

 

[amberwolf]

The Brainpower controller/S886 display only turns the wheel when hooked up and activated, there's no speed control, nor does the peddle assist or thumb throttle do anything.

There may be a pair of "learn" wires connected to each other. These need to be disconnected to use the controller normally, only connecting them once to setup the controller with a particular motor.

Alternately, if the PAS and throttle both have 3-pin connectors, you might have them swapped.

 

[Stefancos]

There may be a pair of "learn" wires connected to each other. These need to be disconnected to use the controller normally, only connecting them once to setup the controller with a particular motor.

Alternately, if the PAS and throttle both have 3-pin connectors, you might have them swapped.

I disconnected the Intelligent Identification wires.
The controller now acknowledges the pedal assist and turns whenever i turn the pedals.
Still no speed control though, the wheel turns at one speed.

The thumb throttle doesnt seem to work at all.

 

[docw009]

You've done the first step by dIsconnecting the learning wires.
Check the walk mode.

Having PAS work could mean you've sorted that out, Does it run only with the crank turning? If it's always running, you may have the PAS connected to the throttle.

On my Brainpower controller, which I bought in 2017. throttle was a 3pin male connector and PAS was a 3 pin female connector. That's opposite of what KT usually does with their connectors,

 

[Stefancos]

You've done the first step by dIsconnecting the learning wires.
Check the walk mode.

Having PAS work could mean you've sorted that out, Does it run only with the crank turning? If it's always running, you may have the PAS connected to the throttle.

The motor only turns when I'm rotating the pedals. So thats good.

On my Brainpower controller, which I bought in 2017. throttle was a 3pin male connector and PAS was a 3 pin female connector. That's opposite of what KT usually does with their connectors,

Yes, same with mine. I had to cut the connectors on both the controller and the thumb throttle lead. Connecting the wires, black, white, red on both doesnt do anything though.

Below is where I connected the PAS and Thumb Throttle.

 

[amberwolf]

Since the PAS puts out pulses, rather than a variable voltage, then swapping them could result in exactly what you get--no thorttle operation, but steady single speed when pedalling.

The PAS pulses are close enough together to appear to the controller, with it's likely built-in throttle ramping, to look like a steady throttle voltage somewhere around half-throttle. Does the wheel seem to be turning at roughly half of full speed?


Try connecting the PAS to the red-white-black, and throttle to red-blue-black. (red to red, black to black, remaining wire to remaining wire).

 

[Stefancos]

Try connecting the PAS to the red-white-black, and throttle to red-blue-black. (red to red, black to black, remaining wire to remaining wire).

I just did that. The pedal assist doesnt work with the red-white-black, only on the red-blue-black. The thumb throttle doesnt work on either.

Another peculiarity is that there's no difference in either having the 5 wires of the hall sensor connected to the controller or not. The motor runs the way it does whether they are plugged in or not.

 

[amberwolf]

I just did that. The pedal assist doesnt work with the red-white-black, only on the red-blue-black. The thumb throttle doesnt work on either.

Just for kicks, if you have'nt already, try using the throttle while pedalling and see if it goes faster. Some systems disable throttle use if not pedalling.

Another peculiarity is that there's no difference in either having the 5 wires of the hall sensor connected to the controller or not. The motor runs the way it does whether they are plugged in or not.

I have a generic controller (two, actually) that is like that--it has hall wires and even a "learn" wire, but it doesn't respond to any hall signals regardless of situation. Even deliberately wiring the halls wrong and not using the learn wire won't cause any change--it just works as sensorless only.

 

[Stefancos]

Just for kicks, if you have'nt already, try using the throttle while pedalling and see if it goes faster. Some systems disable throttle use if not pedalling.

I did, it doesnt do anything. Just using the PAS seems to make the motor turn to max speed already.

I have a generic controller (two, actually) that is like that--it has hall wires and even a "learn" wire, but it doesn't respond to any hall signals regardless of situation. Even deliberately wiring the halls wrong and not using the learn wire won't cause any change--it just works as sensorless only.

All I've been able to get my Brainpower controller to do is turn the wheel using PAS, or when connection the learning wires. Nothing else.