Looking for advice re control unit for a Bafang 8fun motor. It’s a 36v 250w motor, can’t find the same one if I change for a newer type / display screen is it just a case of wiring it in? And away it’ll go of is it not that simple?

Thanks.

1 hour ago, ChrisVito said:

Looking for advice re control unit for a Bafang 8fun motor. It’s a 36v 250w motor, can’t find the same one if I change for a newer type / display screen is it just a case of wiring it in? And away it’ll go of is it not that simple?

Thanks.

You haven't given us any details of thebike, the type of motor, nor the wires attached to the controller, so it's impossible to recommend an alternative. Cenerally, you can use any controller for an ebike as long as you match the type sensored or sensorless motor, the max current and have the necessary wires for what your bike/scooter needs. It's good practice to always buy the controller and LCD as a matched pair to avoid compatibility issues. I always advise to get a KT controller for pedal assist ebikes because they have a very nice and convenient control system, and get the type with block connectors, not the sealed waterproof type for easy testing and debugging.

10 hours ago, D8veh said:

You haven't given us any details of thebike, the type of motor, nor the wires attached to the controller, so it's impossible to recommend an alternative. Cenerally, you can use any controller for an ebike as long as you match the type sensored or sensorless motor, the max current and have the necessary wires for what your bike/scooter needs. It's good practice to always buy the controller and LCD as a matched pair to avoid compatibility issues. I always advise to get a KT controller for pedal assist ebikes because they have a very nice and convenient control system, and get the type with block connectors, not the sealed waterproof type for easy testing and debugging.

Thank you for your reply, apologies i thought I had said about the motor it’s a Bafang rear hub motor fun8 250w brushless BFSWX02/D21110396-1. Please could you explain a little more of what you mean regarding “sensored or senseless”. From my little knowledge I can see it has the battery to a control unit which then runs a screen, wires to the motor, sensor at the peddles and wires into the brake levers.

Sorry this is all new to me.

35 minutes ago, ChrisVito said:

Thank you for your reply, apologies i thought I had said about the motor it’s a Bafang rear hub motor fun8 250w brushless BFSWX02/D21110396-1. Please could you explain a little more of what you mean regarding “sensored or senseless”. From my little knowledge I can see it has the battery to a control unit which then runs a screen, wires to the motor, sensor at the peddles and wires into the brake levers.

Sorry this is all new to me.

Some motors have hall sensors in them and some don't. You need a different type of controller for each. You can tell which you have by the number of pins in the motor connector. Sensored motors mainly have 9 pins, sensorless mainly have 3 or 6 pins.

You can waste a lot of money buying replacement parts, when you don't know what's causing your problems. Exactly what problem are you trying to solve? Why do you want to replace the controller? If it's faulty, how do you know?

Had an error code 6 up on the screen which is a voltage fault. Put a multi meter on the battery and is 41v ish. Went to check for a loose connection / wire and found the controller swimming in water. Have dried it out but it’s flashing that the battery is empty when it’s fully charged, so guessing the control unit is washed out.

Yes, I think it's had it. Unfortunately, you didn't spread out the wires for me to see what you've got, so I can't see if it's sensorless or not.

If that was mine, I'd pull apart any connectors in that rusty mess and clean them properly and reassemble them - maybe with a light smear of Vaseline on them. It is just possible that fouled up corroded connections are the issue - but of course, you might have water inside the controller too.. You won;t know if you don't try it.

After that - you are going to need to do something to seal up that compartment, and to work out how the water got inside in the first place.

The 1st photo is to the motor with the red block being the rear light. The 2nd goes to the screen again with the red block being the front light. 3rd to the pedals. 4th is base of handle bars 1 cable in 3 out. 5th is the screen and 6th is the brakes