Replace dead controller for a 8fun hub motor

[davbruce]

Dear all,

I hope my request will be easy to understand (I speak french) :

I have a bicycle dead after a lot of water drop on it (a leak in the garage directly on the controller).
I suspect the controller to be dead (the display is confirmed dead)

I already exchange the display but I think I don't find the right version/software in it.

Motor : hub 8fun 250watt
Driver : LSW1080-13-1 G3M20211-1592-16

Display : C500B (Bigstone ?)

I buy a C500 display (a see the difference when I receive them), the display works and motor works but there are no communication at all with the display (no speed on the screen, PAS setting change nothing, motor goes to full speed directly when I move pedals. Not possible to activate walkind mode (6km/h is displayed but motor doesn't start).

Because I'm not sure to find the good display version, I think it's better to replace driver/display directly.

Can you help me to find a good solution ? If you need more pictures, don't hesitate.

PS : I have already a kt-lcd5 72v in stock, I don't know if a controller exists for 8fun motor

 

[Chalo]

8fun is Bafang. It's very easy to find appropriate controllers. Pick the appropriate voltage and wattage and put one on order. Make sure the motor and display plugs are the same as what you're replacing.

 

[davbruce]

Thank you for the first feedback.

I search for controller but I don't know if all controller is compatible with all display.
I'm not sure how to choose.

For reminder, it's ok to replace controller and display together.

Concerning the old controller, I removed them from the bike and check the cable :

Power from battery :
White T plug, most of controller come with XT60 or similar connector (see attached)

PAS sensor connector seems standard (yellow 3 pins female)

Connector for display is not as usual also (see attached) : It's a 8 pin directly going to display without 1T4 wires adapter.
From the display, one cable goes to brake lever

Connector for the motor seems to be the usual HIGO 9 Pins

Connector for a brake HWBS (yellow 3 pins male)

I continue to search but I will be very happy with some help.

 

[justlooking808]

Thank you for the first feedback.

I search for controller but I don't know if all controller is compatible with all display.
I'm not sure how to choose.

For reminder, it's ok to replace controller and display together.

Concerning the old controller, I removed them from the bike and check the cable :

Power from battery :
White T plug, most of controller come with XT60 or similar connector (see attached)

PAS sensor connector seems standard (yellow 3 pins female)

Connector for display is not as usual also (see attached) : It's a 8 pin directly going to display without 1T4 wires adapter.
From the display, one cable goes to brake lever

Connector for the motor seems to be the usual HIGO 9 Pins

Connector for a brake HWBS (yellow 3 pins male)

I continue to search but I will be very happy with some help.

if you already have a KT display, you can buy a KT controller : https://www.aliexpress.com/item/10000423707519.html?spm=2114.13010708.0.0.28a24c4druB2IB

that's the link to the aliexpress website to the manufacture. please not that the controller is new version and have the 3 pin brake controllers and all. just make sure you take note of the connections and dimensions of the controller if you want to put it back in the stock location. if you doing a google search, you can search for KT controllers and find some under there. looks like from your pictures your looking for the 15a or 17a version of the controllers if you want stock or if you can fit, i would get the 22a or 25a version and limit the amps via the setting in the controller. hope this helps and happy hunting for a new controller.

 

[davbruce]

Big thanks for this confirmation.

Last question, I have already a kt-lcd5 72v, do you know if it's compatible with 36v battery? (I dont found this INFO in the manual)

 

[Chalo]

I have already a kt-lcd5 72v, do you know if it's compatible with 36v battery? (I dont found this INFO in the manual)

A 72V controller will cut off at 60 volts, give or take. Most KT displays allows you to change this value by a volt or two either way, but not more than that.

 

[davbruce]

I have already a kt-lcd5 72v, do you know if it's compatible with 36v battery? (I dont found this INFO in the manual)

A 72V controller will cut off at 60 volts, give or take. Most KT displays allows you to change this value by a volt or two either way, but not more than that.

I speak about the display, not the controller.. sometimes it's the same for 24,36 and 48v.. I dont know for 72v

 

[Chalo]

I have already a kt-lcd5 72v, do you know if it's compatible with 36v battery? (I dont found this INFO in the manual)

A 72V controller will cut off at 60 volts, give or take. Most KT displays allows you to change this value by a volt or two either way, but not more than that.

I speak about the display, not the controller.. sometimes it's the same for 24,36 and 48v.. I dont know for 72v

I don't know that either.

 

[justlooking808]

I have already a kt-lcd5 72v, do you know if it's compatible with 36v battery? (I dont found this INFO in the manual)

A 72V controller will cut off at 60 volts, give or take. Most KT displays allows you to change this value by a volt or two either way, but not more than that.

I speak about the display, not the controller.. sometimes it's the same for 24,36 and 48v.. I dont know for 72v

usually yes, the display is rated up to 72v and should work fine with volts ranging from 24v to 72v. basically the controller sense the input battery and adjust the controller to what ever voltage it sees. so if it sees a 36v battery plugged in, it will do cut off at 30v by default and the display will work. the controller i believe limits the volts to the display to make if functional.

 

[davbruce]

Hello,

Finally succeeded to replace old controller and display by KT-LCD3 and KT controller.

The adjustment of the controller with the display was ok, only one thing is strange :

Walking mode (6km/h) and differents PAS level are OK (speed and torque increase with level) BUT the motor continues to run even if we exceed the speed of PAS or maximum speed (at 25km/h), torque is null but some consumption and noise remains.

How can i configure correctly the controller ?
And if you have standard configuration for a rear hub controller (bafang 8fun 250w) ?

Thanks