Bafang SWX02 motor failure

[Jack826]

Hello, I have the above motor and after about 1500km of use the motor makes a 'clunking' sound and loses power. To start with it is intermittent, then gradually gets more and more until the motor is unusable. I have had the same thing happen with a few motors now.

I am using a Bafang 8fun controller and 48V battery.

Could anyone suggest what the problem may be?

Thanks,
Jack

 

[Nealh]

The only thing from your description I can think of is a hall or phase wire connection issue.
Check the motor cable joint is mated tightly together and if that doesn't work check that all connections from the motor wire are tight where they connect to the controller, could be a bad wire connection/fitting. Crimping bullets a little tighter will help.

 

[Jack826]

Thanks for the reply. Forgive my lack of motor knowledge, but could you explain 'hall of phase wire connection issue'? Also, 'Motor cable joint' I would assume is the wire that goes from the motor to the controller?

 

[Nealh]

There should be a connector/joint along the rear stay on the drive side make sure it is pushed together until it gives a slight click or up to the marked line also align the two small arrows correctly.
Most likely cause is the phase wires.
The motor will have 3 thick phase wires Blue , Green & Yellow most often connected with 3.5mm/4 mm bullets at the controller, gently pull these apart to feel if they are loose or tight. If loose they will cause arcing and a poor contact, may even see some charring /black soot if so clean and crimp gently for a tight fit.
Some motors use hall sensors (5 or 6) for a smoother quieter motor and internal speed sensing these terminate at the controller in a square white connector, check the pins are good and have not backed out of the fitting and no broken wires ( though generally if a hall wire is broken the motor shouldn't run).

 

[Deleted member 4366]

These clunking, fierce vibration and feeling of jamming from the motor are 9 times out of 10 electrical connection issues, or damage to the motor wires.

The first thing to check is if you have a connector about 12" from the motor, it's pushed in all the way to the line.

After that, you need to follow the wires to the controller to see whether it has the bullet and barrel type connectors. If it does, pull them apart, crimp them down a bit and re-insert.

We need a lot more details about what you have to give specific advice.

 

[Jack826]

Yes the fiece vibration you describe is exactly what happens.
There is only one connection coming from the motor, it is the same as in the image shown below:

There are no other visible connectors between motor and controller. I have not tried opening up the controller, but it looks similar to this one below:

Hope this helps.

 

[Deleted member 4366]

There can either be one or two connectors like that between the controller and the motor, so check that it/they are fully in to the guide-line.

If that doesn't fix it, look very carefully where the wire comes out of the axle to see if there's any damage in that area.

After that, it's most likely a controller issue that could be anything like a bad solder joint, faulty mosfet or faulty capacitor. You'd have to open it up to check or test what's wrong.

 

[Jack826]

Thanks for the reply. I will check what you suggested. I also have some spare controllers that I can try. Will let you know how I get on