Bafang rear hub kit troubleshooting

[gordonfreeman]

Hello everyone,

I have Banfang rear Hub 500W motor kit that worked great for almost two years and then suddenly wouldn't turn ON.

I've done some troubleshooting but I'm having trouble finding where the fault is.

Here's the troubleshooting I've done far:
I've measured the battery DC output and it looks good
Unplugged all break sensors, PAS sensor, display and jumped P+ and PL pins, motor didn't move.
I've check the main wiring harness continuity with the multimeter, wiring is testing ok.
I've open the motor did a visual check, nothing looks burned.
I've ordered a new controller unit, nothing turns ON with the new controller.

So I'm bit lost now what to check next.
Anyone that could help or has any ideas where to look next?


My Bafang Kit details:
P850C Display
motor G020.500.DC
Battery 17.5Ah
contoller: VCSV126-017-48T

 

[indianajo]

Measure the resistance between each 2 of the 3 phase wires. Should be about .5 ohm.
Measure on diode scale the 3 hall effect pickup wires to ground. Should be about 1 diode drop in one direction, 9999 the other.
New controller didn't work, could try a new motor. I have a 1000 w gearless motor I hate because of the drag when unpowered, but keep it because it is new and practically unused. If controller is working & wiring is right it does work.

 

[rich c]

Is the motor completely dead, or will it shudder a bit and then dead? I had one where a hall sensor failed at 1,700 miles. I could boot it up and push the throttle. It would do the shudder and die.

 

[stanmiller]

Assuming something wrong in the motor, you could get new motor and swap out the core without needing to respoke motor into wheel.

Bafang 500W/750W 36V/48V Rear hub motor SWX02/ RM G020 engine-greenbikekit.com BBS, ebike batteries, Bafang M620, Bafang M600, Bafang M500, Bafang M510, KT controller with display-GreenBikeKit.com

Bafang 500W/750W 36V/48V Rear hub motor SWX02/ RM G020 engine for high speed mountian ebike replacement.

www.greenbikekit.com

I have the same kit on two bikes. Though never had a motor fail.

A few years back, @Browneye had one of these kits and motor died. Tried new controller and didn't help. Swapped core and that fixed.

 

[AHicks]

Hello everyone,

I have Banfang rear Hub 500W motor kit that worked great for almost two years and then suddenly wouldn't turn ON.

I've done some troubleshooting but I'm having trouble finding where the fault is.

Here's the troubleshooting I've done far:
I've measured the battery DC output and it looks good
Unplugged all break sensors, PAS sensor, display and jumped P+ and PL pins, motor didn't move.
I've check the main wiring harness continuity with the multimeter, wiring is testing ok.
I've open the motor did a visual check, nothing looks burned.
I've ordered a new controller unit, nothing turns ON with the new controller.

So I'm bit lost now what to check next.
Anyone that could help or has any ideas where to look next?


My Bafang Kit details:
P850C Display
motor G020.500.DC
Battery 17.5Ah
contoller: VCSV126-017-48T

This may seem too simple, but wondering if you're holding down the "on" button long enough? I have an 850C and it seems like it's taking it's sweet time to turn on or off. Maybe 20-30 seconds?

 

[gordonfreeman]

Hi all,

Thanks for all the suggestions. I finally got some time redo some testing.

Measure the resistance between each 2 of the 3 phase wires. Should be about .5 ohm.
Measure on diode scale the 3 hall effect pickup wires to ground. Should be about 1 diode drop in one direction, 9999 the other.
New controller didn't work, could try a new motor. I have a 1000 w gearless motor I hate because of the drag when unpowered, but keep it because it is new and practically unused. If controller is working & wiring is right it does work.

The resistance between each 2 of the 3 phase wires is 0.2 ohm.
Not really sure how to measure/test the hall sensors.

Is the motor completely dead, or will it shudder a bit and then dead? I had one where a hall sensor failed at 1,700 miles. I could boot it up and push the throttle. It would do the shudder and die.

With a jump cable on the P+ and PL pins I noticed that with the new controller, the motor does some noise/clicking when I press the the throttle.
When I try to turn the wheel manually backwards with full throttle there's some resistance on the motor, when I release the throttle the resistance is gone.
But that's only with the brand new controller, it's not doing it with the original controller.

This may seem too simple, but wondering if you're holding down the "on" button long enough? I have an 850C and it seems like it's taking it's sweet time to turn on or off. Maybe 20-30 seconds?

Definitely not the issue.



Assuming it's a motor issue, is it normal that the screen doesn't turn on. Shouldn't the screen turn on just with the battery and controller plugged?

Thanks

 

[Jeffery M]

Hello everyone,

I have Banfang rear Hub 500W motor kit that worked great for almost two years and then suddenly wouldn't turn ON.

I've done some troubleshooting but I'm having trouble finding where the fault is.

Here's the troubleshooting I've done far:
I've measured the battery DC output and it looks good
Unplugged all break sensors, PAS sensor, display and jumped P+ and PL pins, motor didn't move.
I've check the main wiring harness continuity with the multimeter, wiring is testing ok.
I've open the motor did a visual check, nothing looks burned.
I've ordered a new controller unit, nothing turns ON with the new controller.

So I'm bit lost now what to check next.
Anyone that could help or has any ideas where to look next?


My Bafang Kit details:
P850C Display
motor G020.500.DC
Battery 17.5Ah
contoller: VCSV126-017-48T

I've got this same controller and i don't see where to plug in the display. am i missing some adapter cables?