Bafang BBSxx - fault finding and fixes

[Mark-az]

I don't know how to get this pinout to display... sorry.

I received no replies from the vendor so I did a bit of testing today.

It is a bad C965 display/switch.

Controller/motor works with a second display (green wire from my bike's C965 to SWMBO's controller/motor).
SWMBO's C965 does not work with my controller/motor.

I'll try to get some response from the vendor now that I have identified the failing part.

I really hoped that it was a bad connector in the motor so I also removed the unit, disassembled it and checked the connections in there. No joy. The all connections looked great. Now I get to put the motor/controller all back together after I get some non-acetic acid silicone sealant.

 

[CdnE90]

looks like I have a diffent board 9fet 750w

wiring is probably the same.

Thanks mushymelon! Although it was a different board, the wiring is the same. I soldered on some new leads and bench tested the speedo sensor. Everything seems to be working properly.

Now, to address the issue that caused the broken wires - the movement of the motor in the bottom bracket. The bottom bracket is deeply scored where the steel fixing plate sits against the bike. I need to file it down so it's smoother, or the fixing plate won't grip the BB.

Does anyone have a trick to getting the "M33" nut to 30-40 N-m as stated in the install manual?

 

[Arvicola Terrestris]

Does anyone have a trick to getting the "M33" nut to 30-40 N-m as stated in the install manual?

Use a slot wrench and put a 1m pipe over the handle of the wrench, now the wrench is 1meter long.

Then put 3-4 kilogram of pressure (or a weight) on the end of this 1meter long wrench, now you are applying 30-40Nm to the nut.

/philip

 

[bono]

Hey Guys,

I posted this in general section, but somebody directed me to this thread. I will read the thread later today, but seems like I am not the only one with the noise. My Bafang BBS02 was quiet for about 1100 miles. Recently it started making a noise. Please see a short video

https://www.youtube.com/watch?v=VV7UvRi6bAc

The kit is about six months old bought from http://em3ev.net/. If you have a quick suggestion how to fix it, I would appreciate it!

Thank you!

 

[tomjasz]

I'm sure Paul will make it right. The gear is an fairly easy fix. But i'd think the warranty would come into play. Frustrating but the three dealers I've talked to haven't had a lot of failures. As a matter of fact very very few. Good luck thankfully you bought from a reliable source. There's a post or two, I'm looking and I'm sure others are too, describing the gear location and replacement.

 

[bono]

Thanks. I have already replaced the controller in my bbs02. Paul informed me about a potential problem with the controller prior to having any problems.

Yeah, this is frustrating. This is my commuter bike, so I need to fix this as soon as possible...

 

[tomjasz]

I have a spare gear...
If that's what it needs.
Sorry, it is frustrating to be the one that goes down, twice! OUCH!

california bikes might be the fastest for parts..
http://california-ebike.com/product/bafang-8fun-mid-drive-replacement-parts/

 

[bono]

Thank you! This helpful.

 

[samsavvas]

Hey Guys,

I posted this in general section, but somebody directed me to this thread. I will read the thread later today, but seems like I am not the only one with the noise. My Bafang BBS02 was quiet for about 1100 miles. Recently it started making a noise. Please see a short video

https://www.youtube.com/watch?v=VV7UvRi6bAc

The kit is about six months old bought from http://em3ev.net/. If you have a quick suggestion how to fix it, I would appreciate it!

Thank you!

Hi Bono,

The redirect was from me - just thought you might get more assistance here. You might want to read some earlier thread posts starting here: http://endless-sphere.com/forums/viewtopic.php?f=28&t=58898

I have noises myself at the moment in a relatively new 350W drive so I too am rereading these posts prior to getting the screwdrivers out.

Savvas.

 

[bono]

I still hope that Paul from http://em3ev.net/ will respond to my email and will help with this. I am not a big fan of fixing that kind of stuff...

 

[cwah]

Everytime I turn the pedal I can hear a small click. It does happen always at the same place after a full turn whether it's clockwise or counter clockwise.

Not issue with the motor at all when I turn full throttle. It only happen when I turn pedals.

Any idea what it could be?

 

[brakestad]

Hi Everyone,

I have a problem with my Bafang 250w kit with the C961 display.

The power comes and goes without any error message in the display. It worked fine for a couple of weeks before suddenly the power was gone and I got an error code 07 which is said to be over voltage protection. Then the power came and went for a while until it was permanently gone. After a week it started to work again. Now it mostly works but it happens that the power is lost for a while, but there isn't any error codes in the display.

I have tried with another battery so I have ruled out the battery. Any other that have similar problems? Could it be the wiring to the battery? I haven’t connected the brakes, could that lead to this?

Thanks

Now the engine have stopped working permanently and the error code 07 is on all the time.

I opened the engine today and the green wire going to the motor had damaged insulation. See the attached picture. Can this be the cause of the error code 07 that is said to be “over voltage protection”? Any suggestion on how to proceed? How can i check whether this is the fault? I got a multimeter but haven’t got any experience with it, so any tips are greatly appreciated.

Thanks for any help.

 

[Kepler]

That does not look good. Looks like the phase wire is heat damaged. My long distance diagnosis is that the motor may have failed. Unfortunately the motor is not available as a spare part and may well mean a replacement drive is required.

You need to send the picture your supplier (presuming you haven't already done that) and see what they say. They might sent you a controller to try as first point.

Might pay to break the drive down further and have a look at the motor windings directly.

 

[brakestad]

Thanks for the help. It helps a lot, but hopefully you aren’t correct.

I will open the engine and see how it looks. I have also send an email to the supplier ELifebike, but haven’t heard anything back yet.

Thanks

 

[brakestad]

Hi,

I opened up the engine and everything looked nice. No sign of any burning.

Then i dragged out the multimeter and followed this guide:

Use your multimeter in the ohm (resistance) setting. Check the resistance amoung the 3 wires from the motor (in pairs). The ohms should be about the same between any 2 wires. If you have one set with much lower resistance, you have an open coil in the motor. If you have a set with much higher ohm reading, you have a shorted coil (motor should smell burned).
If the motor checks out, do the same on the 3 wires to the ESC. Again, you should get about the same readings between any pair of wires. If you have a much lower ohm reading, one or more FET transistors are open in the ESC. You should never have a short in the ESC without significant circuit damage. That would be obvious.
These are crude tests but they should get you close enough to figuring out if it is the motor or ESC


When checking the motor side everything was fine. When i checked the controller side i couldn't get consistent results. So I lean against that the controller is blown. I also get the same error message when the motor is disconnected, which i guess indicate that the motor isn't the problem. Does it sound correct or could it be something else?

Any other way that i can check the controller?

I tride this guide but couldn't understand what B- is:

circuit wrote:
A faint click on startup attempt sounds like a shorted phase. Most common reson is shorted mosfet, most likely low side. That is easy to check:
1. Take a multimeter and switch it to diode (-<|-) mode.
2. Connect red wire to B-.
3. Connect black wire to each phase. You should see redings around 300-700. If you see something like 002, then you have a blown mosfet. Replace it or bring the unit to electronics workshop to do the job.
4. Repeat steps 2 and 3, but with B+ and switch black with red.

 

[Tom L]

"B-" is referring to the wire that goes to the battery negative terminal (not the actual battery negative terminal itself).

 

[tomjasz]

BBS0X tools on eBay,

http://stores.ebay.com/californiaebike?_trksid=p2054897.l2563

 

[cwah]

Everytime I turn the pedal I can hear a small click. It does happen always at the same place after a full turn whether it's clockwise or counter clockwise.

Not issue with the motor at all when I turn full throttle. It only happen when I turn pedals.

Any idea what it could be?

I think it's a problem with the bottom bracket. Isn't bafang supposed to have 2 years warranty on the motor? How can I sort that out?

 

[Arctic]

I have a BBS01 250 W, with a 10 Ah bottle battery.

After two months of use I've recently encountered some problems.

The last week, 9/10 times using the bike this has happened: I power on the system. The display turns on, and everything seems normal.
Then, the moment I start pedaling, and the assist should kick in, the system shuts off.

If I click my battery's physical button to check the status via the led lights on the battery itself, it just flashes for a quarter of a second.
If I wait a minute or so, and then click the button on the battery, it gives me a normal reading (most of the occasions indicating a full battery, with five led lights shining green). I can then turn on the system again. But the same happens again: If I start pedaling, the system turns off.

At thursday I parked the bike outside a shopping mall for an hour or so, after having ridden around with no power the whole afternoon.
When I came back out all of a sudden everything was working fine, and I could ride all the way home at full assist (4 km, mostly uphill).

I've checked the battery with a multimeter, and it reads 39 V - as you would expect. Still it's the battery I'm focusing on, seeing how I had some trouble charging it a couple of weeks ago. But I'm not sure where to go from here. Any suggestions?

 

[df9517]

Could someone point me in the right direction please:

System is BBS01 with C961 display

System has been working well for like 3000 km.

Now the engine wont start. I have tried using the throttle, pedalling and using + sign to get walking assistance. Nothing happens.

Note:
- I get no error messages at all and display looks as normal. Also the speed information with pedaling without assist works so speed sensor should be okay.
- I have checked with another display, cables and throttle but situation remains the same.
- There is a rough sound when pedaling backwards which was not there before.

What to do?

 

[mushymelon]

Could someone point me in the right direction please:

System is BBS01 with C961 display

System has been working well for like 3000 km.

Now the engine wont start. I have tried using the throttle, pedalling and using + sign to get walking assistance. Nothing happens.

Note:
- I get no error messages at all and display looks as normal. Also the speed information with pedaling without assist works so speed sensor should be okay.
- I have checked with another display, cables and throttle but situation remains the same.
- There is a rough sound when pedaling backwards which was not there before.

What to do?

Does the motor make a slight clicking sound when using the throttle?

The rough sounds are probably a separate issue.

 

[Aushiker]

Now the engine wont start. I have tried using the throttle, pedalling and using + sign to get walking assistance. Nothing happens.

Working through some basic checks:

(1) Battery charge?
(2) Output from battery correct?
(3) Voltage correct on output side of the power cable from the battery?

I had a similar experience and it was caused by voltage drop, i.e., bad connections. I would be checking carefully all connections from the battery to the motor to make sure the correct voltage is getting through to start with.

Andrew

 

[mushymelon]

looks like I have a diffent board 9fet 750w

wiring is probably the same.

Thanks mushymelon! Although it was a different board, the wiring is the same. I soldered on some new leads and bench tested the speedo sensor. Everything seems to be working properly.

Now, to address the issue that caused the broken wires - the movement of the motor in the bottom bracket. The bottom bracket is deeply scored where the steel fixing plate sits against the bike. I need to file it down so it's smoother, or the fixing plate won't grip the BB.

Does anyone have a trick to getting the "M33" nut to 30-40 N-m as stated in the install manual?

I would cleanup the bb with a belt sander to get it nice and flat.

Ordered an m33 replacement kit with my order. I used two nuts and ditched the beauty ring, Re torqued it after my first ride and it hasn't moved since.

http://www.greenbikekit.com/bafang-bbs01-m33-nut.html#



My preferred tool for this job.

 

[df9517]

Could someone point me in the right direction please:

System is BBS01 with C961 display

System has been working well for like 3000 km.

Now the engine wont start. I have tried using the throttle, pedalling and using + sign to get walking assistance. Nothing happens.

Note:
- I get no error messages at all and display looks as normal. Also the speed information with pedaling without assist works so speed sensor should be okay.
- I have checked with another display, cables and throttle but situation remains the same.
- There is a rough sound when pedaling backwards which was not there before.

What to do?

Does the motor make a slight clicking sound when using the throttle?

The rough sounds are probably a separate issue.

It does make a very light hardy noticable clicking sound when using the throttle.

 

[df9517]

Now the engine wont start. I have tried using the throttle, pedalling and using + sign to get walking assistance. Nothing happens.

Working through some basic checks:

(1) Battery charge?
(2) Output from battery correct?
(3) Voltage correct on output side of the power cable from the battery?

I had a similar experience and it was caused by voltage drop, i.e., bad connections. I would be checking carefully all connections from the battery to the motor to make sure the correct voltage is getting through to start with.

Andrew

But if the battery is the problem, shouldnt the display be turned off as well? But you might be right, I should probably check the battery. It was fully charged but indeed I did not check the voltage vecause of that the display was on there shouldn't be any problem I thought.