Controller for Bafang 750 watt motor

[bpmcallorum]

Have any of you successfully paired up a Kelly controller, Sabvoton controller, or a VOTOL EM-50 controller with a Bafang 750 watt geared rear hub motor?

 

[AGS]

I’m guessing not by the lack of response.

Out of interest, what kind of power are you looking to run your motor at?

Ive been reading that some people run them at over 3kW at 72 volts with oil cooling and steel gears.

 

[bpmcallorum]

My 58.8v batteries can do 30 Amps continuous.

So that is what I would want to set the controller at.

 

[AGS]

I’m running an SWX02 at 52 volts, 1500 watts, just using a KT 12 FET controller because it’s relatively cheap, reliable, easy to configure and does the job nicely.

 

[bpmcallorum]

The rated current on that KT is only 15 amps.

I have done electronics my whole life (I’m 51). But I’ve only been modding my ebike for 3 months.

I’ve had many people who know way more than me tell me to get a much stronger controller than I need and program it down to 30 amps.

But it is crazy difficult to wire and program these controllers with a “foreign” motor.

One issue is I do not have a PC, just a Mac.

The Sabvoton 72100 looks like I can at least program it from my iPhone via Bluetooth.

If you know how to do this I would love some guidance.

 

[AGS]

There are many KT controllers. Mine is rated at 30 amps. KTs don’t require a pc connection for basic setup. Everything you need to do can be configured via the display.

Your motor won’t really benefit from things like field weakening so basic configuration is all that’s needed.

Sensored Brushless Motor Controller 48V 1000/1500W 12-FET 30A KT Sine

12 fet 30A KT sine wave brushless controller. Includes phase wire connector box. PLEASE NOTE: This is a sensored brushless motor controller. Your motor should have 8 or 9 wires in order to function with this controller. If your motor only has 3 wires, you will require a sensorless controller...

torquetech.co.uk

 

[bpmcallorum]

Thank you so much for your help.

I’ll look again and closer at the KT controllers.

 

[bpmcallorum]

 

[AGS]

The Sabvaton 72100 is a very powerful controller. You would have to throttle it right back to protect your battery and your motor.

 

[bpmcallorum]

Thank you so much for your help.

I’ll look again and closer at the KT controllers.

My motor only has 3 wires and this says it’s not for me.

In fact it only has ONE wire…..with 3 pins (sub-wires)

 

[bpmcallorum]

The Sabvaton 72100 is a very powerful controller. You would have to throttle it right back to protect you battery.

I understand…that’s the whole point…and what many people have recommended.

 

[E-HP]

.

I’ve had many people who know way more than me tell me to get a much stronger controller than I need and program it down to 30 amps.

But it is crazy difficult to wire and program these controllers with a “foreign” motor.

The question is, do those people know way more than the ES forum? Those controllers are way overkill for a 30A application (which those people should have told you), and the KT controllers fit that range nicely and can limit the current through the simple display interface, not by programming. If you want to spend several hundred dollars to do the job of a $60 controller, in order to learn how to program a controller and what all of the parameters do, then I can't argue whether that tuition cost is worth it or not, but if you just need a reliable controller that works, then the KT's are a simple solution. I climbed a lot of steep hills when I had my KT, and it never got past luke warm.

 

[E-HP]

My motor only has 3 wires and this says it’s not for me.

In fact it only has ONE wire…..with 3 pins (sub-wires)

You probably should have started with that info. Your motor will only run with a sensorless controller, so maybe that's why people are suggesting those brands. I'm not sure I'd invest that much to get a sensorless motor going (I'd replace the noisy motor and get the right controller for the job).

 

[AGS]

This controller will run sensorless and is even cheaper, but I personally would start by replacing the motor with a sensored motor because they are much more efficient and less noisy.

Sensorless Brushless Motor Controller DC 36V/48V 1000-1500W 12-FET 35A

12 fet 35A KT torque simulation sensorless brushless controller. PLEASE NOTE: This is a sensorless brushless motor controller, intended for motors with only 3 wires. If your motor has 8 or 9 wires, it can be used with this controller without the hall sensors connected, by just connecting the 3...

torquetech.co.uk

What model Bafang motor do you have that doesn’t have hall sensors built in?

 

[AGS]

I may be wrong, but I have always been under the impression that all Bafang (G060/G062) 750 watt geared rear hub motors have inbuilt hall sensors.

 

[bpmcallorum]

The question is, do those people know way more than the ES forum? Those controllers are way overkill for a 30A application (which those people should have told you), and the KT controllers fit that range nicely and can limit the current through the simple display interface, not by programming. If you want to spend several hundred dollars to do the job of a $60 controller, in order to learn how to program a controller and what all of the parameters do, then I can't argue whether that tuition cost is worth it or not, but if you just need a reliable controller that works, then the KT's are a simple solution. I climbed a lot of steep hills when I had my KT, and it never got past luke warm.

This is super helpful. Thank you.

Did you see what they said though about my 3 wire motor?

 

[E-HP]

This is super helpful. Thank you.

Did you see what they said though about my 3 wire motor?

Yes, I saw your post after I posted mine. 3 wires means it doesn't have sensors, and the KT controllers that I'm familiar with only work with sensored motors. The downside of the sensorless motors, besides the noise, are the rough starting from a standstill (or worse, on a hill), which is why it would be better to invest that money in a motor than an expensive controller. The controllers you mentioned will work, but it's sort of like putting lipstick on a pig.

 

[AHicks]

It's rarely pushed hard, but I have a 35a KT controller running a 1000w MAC 12t geared hub. Been running flawlessly, without even one hiccup, since I installed it in late 2016.

No direct experience dealing with a sensorless motor, but my understanding on the topic is that the sensors do help get the motor turning from a full stop. The sine type controllers (the quiet ones) may need sensors, but I'm not positive on that. Betting you're looking for a square wave controller for sensorless operation.....

Last, regarding the KT installs, do not be tempted to bury it in a bag or something if you're looking for max performance. Those cooling fins need air circulation to keep it cool.

 

[bpmcallorum]

Yes, I saw your post after I posted mine. 3 wires means it doesn't have sensors, and the KT controllers that I'm familiar with only work with sensored motors. The downside of the sensorless motors, besides the noise, are the rough starting from a standstill (or worse, on a hill), which is why it would be better to invest that money in a motor than an expensive controller. The controllers you mentioned will work, but it's sort of like putting lipstick on a pig.

I’ve looked into getting a new motor extensively. Received many quotes. Trust me.

I have a very custom wheel size. 18”
Rim, 22” inch rubber to rubber diameter.

I plan to evolve my bike in the future to a whole new motor/battery/controller. And in fact I have a few suppliers for a whole new system. Because they want $$$$$.

For now I honestly just got fired from my job and I am trying to go to a new workplace 25 miles away everyday.

It would simply be preferable if I could just get a bulletproof 30amp controller to work with my 750 watt Bafang geared rear hub motor for now.

I have burned through 6!!!!!! Bolton 35amp controllers for one reason or another this year (very very long story). I hate Mr. Bolton.

I ride a heavy cargo bike with no chain throttle only all night long. I have about 60 amp hours in my batteries. It’s a low powered e-scooter.

And the controllers with small capacitors die!!! I would even say they LIE about being able to do 30 amps continuous.

That’s why everyone says to buy a stronger controller and program it down. Most controllers are under $200, that price point is of no concern to me.

I suppose you will say get a 20” kit with no battery….if u have a link to something that will definitely work on a Radwagon 4 then I’m all ears.

 

[bpmcallorum]

Have any of you successfully paired up a Kelly controller, Sabvoton controller, or a VOTOL EM-50 controller with a Bafang 750 watt geared rear hub motor?

48 - 60v 750w Bafang geared rear hub motor

This rear-drive motor, which is compatible with the disc brake, has a rated power of 250-750W, a reduction ratio of 1: 5 and a maximum torque of 80 N.m, providing ideal power for vehicles. Strong and efficient, this motor, working together with a fre

electrobikeworld.com

My motor.

 

[bpmcallorum]

This controller will run sensorless and is even cheaper, but I personally would start by replacing the motor with a sensored motor because they are much more efficient and less noisy.

Sensorless Brushless Motor Controller DC 36V/48V 1000-1500W 12-FET 35A

12 fet 35A KT torque simulation sensorless brushless controller. PLEASE NOTE: This is a sensorless brushless motor controller, intended for motors with only 3 wires. If your motor has 8 or 9 wires, it can be used with this controller without the hall sensors connected, by just connecting the 3...

torquetech.co.uk

What model Bafang motor do you have that doesn’t have hall sensors built in?

48 - 60v 750w Bafang geared rear hub motor

This rear-drive motor, which is compatible with the disc brake, has a rated power of 250-750W, a reduction ratio of 1: 5 and a maximum torque of 80 N.m, providing ideal power for vehicles. Strong and efficient, this motor, working together with a fre

electrobikeworld.com

 

[AGS]

Ah, now we are beginning to understand why you are looking at such a big controller.

You have been asking a lot of those controllers to be run on a heavy cargo bike all night long on throttle only. They have probably all overheated on you. The motor has done well to survive that amount of work.

The wording on that link you posted is confusing you into thinking that you have a sensorless motor.

“You will need our 35a KT controllers to run with this motor for the Sondors ebike. For the Rad ebikes or any ebikes with the compatible 3pin motor plug you can still use the stock controller/LCD. This "true" 750w motor is more powerful and robust than the 350 & 500w Bafang motor and it's the easiest and best way to replace them”.​

There is also a photograph of a Julet Z916 connector that shows the 3 large motor pins in the middle, but the much smaller hall sensor pins are on the outside and are not so easy to see.

G060 motors all run with hall sensors, so take a closer look before choosing your next controller.

Also those Bolton controllers look exactly the same as the KT controller that I linked to earlier in the thread.

 

[E-HP]

I’ve looked into getting a new motor extensively. Received many quotes. Trust me.

I have a very custom wheel size. 18”
Rim, 22” inch rubber to rubber diameter.

I plan to evolve my bike in the future to a whole new motor/battery/controller. And in fact I have a few suppliers for a whole new system. Because they want $$$$$.

For now I honestly just got fired from my job and I am trying to go to a new workplace 25 miles away everyday.

It would simply be preferable if I could just get a bulletproof 30amp controller to work with my 750 watt Bafang geared rear hub motor for now.

I have burned through 6!!!!!! Bolton 35amp controllers for one reason or another this year (very very long story). I hate Mr. Bolton.

I ride a heavy cargo bike with no chain throttle only all night long. I have about 60 amp hours in my batteries. It’s a low powered e-scooter.

And the controllers with small capacitors die!!! I would even say they LIE about being able to do 30 amps continuous.

That’s why everyone says to buy a stronger controller and program it down. Most controllers are under $200, that price point is of no concern to me.

I suppose you will say get a 20” kit with no battery….if u have a link to something that will definitely work on a Radwagon 4 then I’m all ears.

This information is helpful, since it provides some background, and insights on your future upgrade path. Given that, you may want to get the right controller that will work for the future bike, but still run sensorless for the current setup. I still wouldn't recommend a programable unit, since you are only trying to limit current. Is your controller mounted where it gets good airflow? The number of failures make it seem like something else may be contributing.

An option would be to get a big cheap dumb (no programming or brains) dual mode controller (sensored/sensorless) and a Cycle Analyst. That way, you can control the current limit, have current roll back when you reach the limit you set, or due to voltage sag, etc. You could even add a heat sensor to the cheap controller for a couple of bucks, and have temp rollback when the controller gets to hot. The CA would be a worthwhile long term investment that will work with any controller, and provide a lot of options (cruise control, etc.).

 

[bpmcallorum]

This controller will run sensorless and is even cheaper, but I personally would start by replacing the motor with a sensored motor because they are much more efficient and less noisy.

Sensorless Brushless Motor Controller DC 36V/48V 1000-1500W 12-FET 35A

12 fet 35A KT torque simulation sensorless brushless controller. PLEASE NOTE: This is a sensorless brushless motor controller, intended for motors with only 3 wires. If your motor has 8 or 9 wires, it can be used with this controller without the hall sensors connected, by just connecting the 3...

torquetech.co.uk

What model Bafang motor do you have that doesn’t have hall sensors built in?

If you know of a 22" fat tire wheel mounted on a 18" motorcycle rim with a great motor that is paired up with a great controller with larger capacitors than necessary that can easily be programmed down to 30 amps please let me know!!!

It's like finding a unicorn.

I promise I have spoken with QT motors directly, Grin Tech, Johnny Nerd Out, CaliBikes, SIAECOSYS, "FB Dudes" and tens of other suppliers...."Powerful Lithium" was very helpful.

But please understand the difference between a couple hundred dollars and over a thousand dollars. My quote from Powerful Lithium is in the $3,300 range.

I don't mind scrapping my motor but my custom wheel size makes everything 1000x more difficult.

It currently feels impossible to get a good controller working on my bike honestly.

I could install another Bolton tomorrow in under 10 minutes. I even know how to make it last....better than I used to know.

But when it dies it would be the 7th one and I would feel like a complete idiot 7 times over.

People have quoted the definition of insanity to me about doing the same thing and expecting different results.

Also, I would have to stay under 22 miles an hour........that is too slow for me!!!

 

[bpmcallorum]

Ah, now we are beginning to understand why you are looking at such a big controller.

You have been asking a lot of those Boltons to be run on a heavy cargo bike all night long on throttle only. They have probably all overheated on you. The motor has done well to survive that amount of work.

The wording on that link you posted is confusing.

“You will need our 35a KT controllers to run with this motor for the Sondors ebike. For the Rad ebikes or any ebikes with the compatible 3pin motor plug you can still use the stock controller/LCD. This "true" 750w motor is more powerful and robust than the 350 & 500w Bafang motor and it's the easiest and best way to replace them”.​

There is also a photograph of a Julet 916 connector that shows the 3 large motor pins in the middle, but the much smaller hall sensor pins are on the outside and are not so easy to see.

G060 motors all run with hall sensors, so take a closer look before choosing your next controller.

Also those Bolton controllers look exactly the same as the KT controller that I linked to earlier in the thread.

From Grin