Bafang BBSxx - fault finding and fixes

[Kepler]

This plug is where I would be concentrating on before writing off the controller.

 

[cwah]

+1

Does looks like a controller issue. I wonder how to get parts.

you can also plug it to an external controller until you find a spare one

 

[speedmd]

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.

No shorts on phase wires either controller or motor side. Connector / connections look /rings out perfect. Not sure I follow the step 2 and on above. Have it all apart, but don't want to mess with a potted controller. Looks to be a junk pile filler at this point. Not sure I will ever trust this thing again. Fun while it lasted (less than ten miles). Hopefully I can nail trouble down a bit better soon or get rid of this kit for good. Not living with a less than bullet proof easy to work /sort out system.

 

[cwah]

can't you get a spare sensorless controller, plug the 3 phase wires, and see if the issue comes from there?

 

[dumbass]

I don't think is is a faulty throttle. The walking pace activation would still work if the throttle was faulty.

You are confident the hall wire plug inside the drive is well seated and that a contact hasn't just pushed out?

Measure the resistance of each phase wire to ground (power in ground and battery disconnected). If any show dead short, the controller is stuffed.

Controllers should be available. TomL got a 750W controller sent to him after he damaged his when working out how the program them. Sound like you need to start pushing your supplier.

Thanks everyone for your help but honestly I'm not much for electronics. If it would fit in my pocket I'd still have my "brick cell phone". :lol:

Kepler; I agree with you it's not the throttle because the "walk" mode from the screen would still work. Or even the pas would work. But everything is 100% dead. Except for a few nudges the motor made while testing the throttle on/off 100 time last night.

As for the Hall plug I actually removed the plug while working on the motor. Before reinstalling it I applied a small amount of OX-Guard connection protection paste. Aligning the plug with the 6 pins is a real PITA. But it did seem to seat perfectly and I applied liquid tape to the plug grommet and everything else. I also checked the small 2 wire plug and it was also well seated.

At this point I'd just like to fine somewhere where I can buy a new controller and get this thing running. I have to agree with speedmd I don't know if I will ever trust this motor again. Or any Bafang products again. At least speedmd got a 10 mile ride before his failed. I got block when mine failed.

It would be nice to put pressure on the supplier but I'm guessing that will be like peeing in the wind. Total aggravation and with no results. I'm saying this because he only had 2 motors (1 each 500w and 750w). Chances are he has no connection to get any spare parts from Bafang. His return policy is 14 days which I exceded. So even EBay won't support me on their purchase protection policy.

Right now if I could get a reasonable deal on a new 750w motor from a quality supplier that could also sell me a new controller I'd jump at it. I'd install the new motor and get my head straight then replace the controller on the defective motor and install it on my wife's bike.

I may take the motor apart again to do the recommended testing. But before I do that, what do you think about replacing the 3 phase wire? I used a lot of liquid tape to hold things together and on that silicon wire I don't think it's going to stick very well.

Any recommendations on where to buy a new 750w and a new controller for the one I already have???

Bob

 

[teslanv]

Check with EM3ev.com
I know Paul sells the 18A controller, and he may be able to source the new 9-FET 25A controller as well.

Also try LeGrand at lectriccycles.com
He was the first US supplier to stock these drives and visits the factory every few months.

 

[speedmd]

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.

Did step 3 and yellow is shorted on mine. Hopefully I can get a new controller.

 

[dumbass]

I communicated with my the EBay supplier (diyebike) and he says he will try to get a new controller for Bafang. I also spoke to Doug at California EBikes and he told me they didn't make a 750w mid-drive with a 20a controller and it should have had a 25a. And even those are undersized which is why they stopped production. I left a message for LaGrange at Lectriccycle to see if he can sell me a 25a controller and reprogram it for a max output of maybe 20a. Doug told me he thinks LaGrange has the software for doing this.

Bob

 

[samsavvas]

I communicated with my the EBay supplier (diyebike) and he says he will try to get a new controller for Bafang. I also spoke to Doug at California EBikes and he told me they didn't make a 750w mid-drive with a 20a controller and it should have had a 25a. And even those are undersized which is why they stopped production. I left a message for LaGrange at Lectriccycle to see if he can sell me a 25a controller and reprogram it for a max output of maybe 20a. Doug told me he thinks LaGrange has the software for doing this.

Bob

Bob,
If you read back through recent posts at the EM3ev site's 'news' page you can read a bit about the upgrading that Bafang is pursuing for the 750W controller. Also there's a longish post just a few pages back reporting on a US-based manufacturer's tour of the factory with similar information.
Savvas.

 

[dumbass]

I communicated with my the EBay supplier (diyebike) and he says he will try to get a new controller for Bafang. I also spoke to Doug at California EBikes and he told me they didn't make a 750w mid-drive with a 20a controller and it should have had a 25a. And even those are undersized which is why they stopped production. I left a message for LaGrange at Lectriccycle to see if he can sell me a 25a controller and reprogram it for a max output of maybe 20a. Doug told me he thinks LaGrange has the software for doing this.

Bob

Bob,
If you read back through recent posts at the EM3ev site's 'news' page you can read a bit about the upgrading that Bafang is pursuing for the 750W controller. Also there's a longish post just a few pages back reporting on a US-based manufacturer's tour of the factory with similar information.
Savvas.

Savvas, Thanks for the site info. I like getting as much info as possible. But honestly, from talking and reading so much on these motors I find it all a little confusing. From what I think is being said is; the 48v 500w motor is the same as the 48v 750w motor. But they install a larger controller in the 750w to give it the added power. Which would help explain why the two units are so similar in price. But please pardon my ignorance in the matter but what I can't understand is; if they are the same motor then why is it OK to run it on the 18a controller and fine tune this controller to 20a but the larger 25a controller isn't good? As I've read several times it is now recommended to de-tune or reset the old 25a controller for a max output of 22a (which is what I'm told LectricCucle is now doing). I relies as you increase amperage you generally increase heat as well. Doug at Cal. Ebike also told me that the new 25a 9 fet will actually be more like a true 30a controller.

The bottom line for me is; the EBay seller sold me a 750w setup with a 25a controller (it's in writing on his posting). But he delivered a motor that is clearly stamped 48v 750w 20a. So what really is this thing, a 500w or a 750w? And then there's the issue of the damaged wiring inside the motor that is un-know for sure how it became damaged.

At this point I told the seller I'm done trying to fix his problem and want a full refund because the motor doesn't work and it was misrepresented as sold. I have also posted a dispute with EBay and my credit card company. Lets face it, when you buy something it should work without having to spend days or weeks of your time to make it run correctly. The seller "claims" he pre-tests each unit before shipping. Great, I tested it on my bike with the rear wheel off the ground for 7 miles and had no problem. But put a load on it and it lasts 1 block! There's no way it could have heated up enough in a block ride to burn out a good controller no matter what size it was. To me that's a defect plain and simple.

At this point I am considering ordering a 48v 500w motor from EM3ev and ask if they can also (later) supply a 25a controller for the 750w just in case I loose the dispute with the seller. Or even just call the 750w a 500w and put an 18a controller on it. Question is; is the controller the only problem or is this going to be a money pit?

Bob

 

[tomjasz]

IMO, LaGrand or Paul are the only sensible choices in this game. LaGrands pricing is more competitive on the BBS01, but after all is said and done if the kit were to be my primary ride I wouldn't hesitate to pay the premium to LaGrand for faster turn around of support and support parts. I have one kit from each. There are pluses and minuses in both columns. But either way there is someone to take responsibility and respond.

 

[amigafan2003]

From what I think is being said is; the 48v 500w motor is the same as the 48v 750w motor.

Correct

But they install a larger controller in the 750w to give it the added power.

No, it's the same controller, just set @ 25 amps instead of 18 amps.

if they are the same motor then why is it OK to run it on the 18a controller and fine tune this controller to 20a but the larger 25a controller isn't good?

It's not the motor that can't take 25amps or the motor that overheats, it's the controller. BTW - you can't take the 500w controller (18 amps) and up it to 20 amps - it's limited to 18amps max in the firmware.

As I've read several times it is now recommended to de-tune or reset the old 25a controller for a max output of 22a (which is what I'm told LectricCucle is now doing).

Correct.

I relies as you increase amperage you generally increase heat as well. Doug at Cal. Ebike also told me that the new 25a 9 fet will actually be more like a true 30a controller.

Correct.

The bottom line for me is; the EBay seller sold me a 750w setup with a 25a controller (it's in writing on his posting). But he delivered a motor that is clearly stamped 48v 750w 20a. So what really is this thing, a 500w or a 750w? And then there's the issue of the damaged wiring inside the motor that is un-know for sure how it became damaged.

At this point I told the seller I'm done trying to fix his problem and want a full refund because the motor doesn't work and it was misrepresented as sold. I have also posted a dispute with EBay and my credit card company. Lets face it, when you buy something it should work without having to spend days or weeks of your time to make it run correctly. The seller "claims" he pre-tests each unit before shipping. Great, I tested it on my bike with the rear wheel off the ground for 7 miles and had no problem. But put a load on it and it lasts 1 block! There's no way it could have heated up enough in a block ride to burn out a good controller no matter what size it was. To me that's a defect plain and simple.

IMHO, you have reasonable grounds for a dispute there, good luck with your CC company!

Question is; is the controller the only problem or is this going to be a money pit?

All ebikes are money pits

 

[tomjasz]

All ebikes are money pits

QFT :wink:

 

[dumbass]

I received a message from the seller requesting I hold off on the EBay dispute until he can get info from the factory. I responded "NO" because that could drag on for who knows how long. And as I told him "how do we know this is the only problem?" I also mentioned the motor has a damaged phase wire that I had to repair.

Does anyone have an "Original" shipping box they can send me? I discarded (DUMN ME!!) mine the day before the motor failed. Technically, I think I am required to send it back in the original shipping case. I would be happy to pay the cost of sending the case and inside foam to me if someone still has it available.

Bob

 

[pexio]

Does anyone have an "Original" shipping box they can send me? I discarded (DUMN ME!!) mine the day before the motor failed. Technically, I think I am required to send it back in the original shipping case. I would be happy to pay the cost of sending the case and inside foam to me if someone still has it available.

Bob

PM me. I have the original boxes for both my kits (which hopefully I won't need anytime soon...).

 

[tomjasz]

22 miles and display LED failure on first kit. Also the throttle is sticking badly. A bit of ACF50 and we'll see how the throttle holds up. Paul somewhere suggested adding an extra to the order. Of course I didn't. DOH! Yesterday the display came up after a few minutes, today, no joy!

 

[dumbass]

22 miles and display LED failure on first kit. Also the throttle is sticking badly. A bit of ACF50 and we'll see how the throttle holds up. Paul somewhere suggested adding an extra to the order. Of course I didn't. DOH! Yesterday the display came up after a few minutes, today, no joy!

I think one of the big problems with the display may actually be in the push button unit. The fact that the cable exits the button unit through the bottom and it has to be bent at a very sharp angle to fit in the allotted slot so it can be mounted to your handlebar. As soon as I saw this and mounted the buttle unit in place I knew this was going to be a problematic design.

Bob

 

[dumbass]

What does it mean if you have conductivity between 2 of the 3 phase wires on the motor? I have no conductivity from and phase wire to the motor side wall but I do from the yellow to blue wire. Does this mean they are shorted together?

Bob

BTW, I am still proceeding with my EBay claim to return the motor as a defect and misrepresented item. So far the seller has offered to try to get me a controller from Bafang which I rejected. He then offered to return $100 and I keep the motor (and it's problem...what ever it is). I also rejected this offer. He has till the 23rd. to come up with something or I guess EBay makes him give me a full refund including shipping both ways.

 

[mphoto]

Hi all, I'm new to this forum and brought my BBS02 500W 48V Bafang 2 week a ago and already clocked up 200km. All is good with the motor running very quite, But when the motor often engages I get a loud click, is this normal?

Cheers all.

 

[skuutti]

I just use the same grease as what I use on the metal gears.

In relation to re assembling the crank section, make sure you don't over tighten this.

I use the following method:

With the shaft and thrust bearing installed, fit the silicon seal, shim, then the two nuts. Screw the first nut down very lightly so it just takes out the end play on the crank. Then screw the second nut on and tighten until you feel the crank just start to bind. Then go back just lightly (both nuts should turn together) so that the crank turns freely.

At first, I would like to thank you all for the great info!
I noticed today that my 750W BBS02 made weird clanks every time I started of stopped pedaling (PAS mode). This happened only after 400 km on the unit.

I took the crank side open and found out that the problem was most likely caused by this silicon seal that was broken. There was some play between the thrust bearings. Because of this the thrust bearings had started jamming and this would only happen when I stopped or started pedaling.

So now I plan to make a new silicone seal and then just put it back together and make sure there is no more play. Hopefully it will work even though the ball cages of the thrust bearings are a bit worn out because of the jamming.

So my question is where should this silicone seal go? What is the correct order for these to go on the axle?
Kepler suggested: crank - nut - nut - shim - seal - bearing.
But on my unit they were like this: crank - nut - shim - (seal?) - nut - bearing (not sure where the seal was since it was crushed between the nut).

 

[skuutti]

Ok. So I fixed the bearing problem. I removed the ball cages from the bearings altogether and filled the bearings with additional balls (6 x 3,2 mm diameter).
Click for picture
Then I made a new rubber seal to prevent water and dirt from getting in.
Click for picture

But unfortunately this didn't fix the problem!
I made a video that demonstrates the problem. At first I tap the throttle (Assist level 1) against rear brake. It makes the click every time I do this. Then I simulate what happens usually when I drive. I stop pedaling and the motor turns off, when I start to pedal again it makes this click like there is some spring loaded and it releases when I touch the pedals.

Remember! This only happens when riding in PAS-mode. When I ride without the motor it doesn't happen and when I ride with only the throttle it doesn't happen!
[youtube]4X3RCYICcSQ[/youtube]

 

[Kepler]

That sounds like a broken tooth on the nylon gear to me. You need to open up the drive and investigate further. could be the sprag clutch letting go under load too. Either way I think you are going to need to tear down the drive I would say.

 

[erabbit]

Ok. So I fixed the bearing problem. I removed the ball cages from the bearings altogether and filled the bearings with additional balls (6 x 3,2 mm diameter).
Click for picture
Then I made a new rubber seal to prevent water and dirt from getting in.
Click for picture

But unfortunately this didn't fix the problem!
I made a video that demonstrates the problem. At first I tap the throttle (Assist level 1) against rear brake. It makes the click every time I do this. Then I simulate what happens usually when I drive. I stop pedaling and the motor turns off, when I start to pedal again it makes this click like there is some spring loaded and it releases when I touch the pedals.

Remember! This only happens when riding in PAS-mode. When I ride without the motor it doesn't happen and when I ride with only the throttle it doesn't happen!
[youtube]4X3RCYICcSQ[/youtube]

Faulty, i had same problem with 350w after 300km, i returned motor and seller change motor.

 

[skuutti]

Thank you for your input. Unfortunately returning the motor isn't an option for me.

Today I took the unit apart. Good thing is that all the gears look perfect, but I just can't figure out what is wrong with it!
I checked the freewheel and I checked the clutch. Both seem to be ok.

My best guess is that this clutch is somehow getting stuck and then it makes the sound when it releases.
I guess I will just have to order spare parts from Greenbikekit and see if it fixes the problem.

Here's a video of the internals.
[youtube]sY9gUmc3DZo[/youtube]

 

[mphoto]

Here is my clunk noise issue only on peddle assist. It mostly happens but occasionally it will engage smooth with minimal noise.

http://youtu.be/d_psqu4MReQ

thank you to every one for contributions to this forum.