Bafang BBSxx - fault finding and fixes

I agree dustNbone.

I haven't cooked a white nylon gear inside my BBS02 yet but I've melted several white gears inside Q hub motors and it was most definitely caused by heat buildup during extended high speed runs. Same motors ran for long time doing 4 mile runs but the 1st time I did 10-12 miles continuous, the white gears became soft and turned to goo.

The BBS02 integrated controller is certainly a quick way to heat the system up to those levels.

I keep the BBS02 around 500W continuous. I do use 1500W peak for a quick burst here and there but for sustained long runs, 500W is the thermally safe zone, IMO.

Alex07 said:

they only work for a short amount of time and quiet at the start and then are hard and expensive to fix and get noisy very soon.

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All we see here are the few problems not the thousands of successes. I've had two running for over two years now and not a problem. Unfortunately to many riders are clueless on riding with this motor. YKick nails it. Lug this motor and you'll kill it. Use your gears and quit treating it like hub motor or motorcycle and it'll run for several thousand miles. The only real problem is Bafangs parts support. SUCKS.

Hi peeps

About 6 months ago I was out on some family property with some relatives and I gave my brother a turn on my BBS02 based mtb
He had a few good runs on it but got a bit stuck on a mound and musty have tried to boot up the motor flat stick on an incline in a high gear, this pritty much instantly cooked her :/
Anyway its been about 6 months an a rough as guts semester of uni (which was also my last! pewpew) and after finishing the first thing I did was pull apart my old BBS02, on deep inspection it appears I have an old controller with p75nf75 fets 1 of the fets tested open circuit so I have ripped that out and have a few STP75nf75's on route from mouser, I know some people advise against going back to these fets, but after having a bash with a few tips there is no way I could be arsed to desolder all the lead free of those fets its a huge mission! besides only 1 was cooked and it ran fine for ages anyway on the 80amp fets!

Now after having a look at the controller I opened up the motor casing and found what where some very dark colored winding's on the stator
I probed the winds abit and there is no leakage from any of the widings back to the metal case/housing, I was going to take of the phase leads and check the individual winding pairs to see if any of the winds have bridged but Im not super keen to pull it down that far.
So I guess I have 2 questions, has anybody had a stator that is this discolored still work? (and there is some wheaping/heat stress marks possibly around so it probably heat)
And do you think its safe to test it after replacing the blown fet?
Oh and is it safe to power my motor from a SMPS My battery may or may not have been stored too long at low charge :/ ? I have a mean well 300w 36v smps and a 600w dc-dc boost converter lying around somewhere.

chilltrout - Black motor windings = never a good sign. I would Hi-pot test to be certain but most likely shorted windings which DC Ohm meter will never be able to detect.

Ykick said:

chilltrout - Black motor windings = never a good sign. I would Hi-pot test to be certain but most likely shorted windings which DC Ohm meter will never be able to detect.

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Yes it can! if you desolder all the phase leads and are left with all the raw copper you test for continuity between each wire and each wire should only be closed circuit at its end
I just don't want to remove the string, heatshink and solder :/

Hi all,

Apologies if this has been covered in the thread already, have looked through quite a few pages without finding anything relevant.

Tonight when I was going to ride home from work, my BBS02 (new model about 10 months old with the upgraded controller) initially worked fine but after a few hundred meters started to cut out above a certain speed and then stopped working completely after approximately 100m from first symptoms. I was riding in a short slight uphill slope in a low gear and PAS 4 (out of 5) and have done the same ride 100s of times in the same way without any issues.

The display is still working fine but the motor does not kick in at all using either PAS or throttle.

It has been snowing and raining a lot the last week and I guess I might have gotten water (possibly including salt as they have been salting the roads) inside the controller and fried it.

What is the best way to diagnose if it is the controller that has crapped out? Any ideas on what else can be at fault?

Cheers,

Andreas

seglare86 said:

Hi all,

Apologies if this has been covered in the thread already, have looked through quite a few pages without finding anything relevant.

Tonight when I was going to ride home from work, my BBS02 (new model about 10 months old with the upgraded controller) initially worked fine but after a few hundred meters started to cut out above a certain speed and then stopped working completely after approximately 100m from first symptoms. I was riding in a short slight uphill slope in a low gear and PAS 4 (out of 5) and have done the same ride 100s of times in the same way without any issues.

The display is still working fine but the motor does not kick in at all using either PAS or throttle.

It has been snowing and raining a lot the last week and I guess I might have gotten water (possibly including salt as they have been salting the roads) inside the controller and fried it.

What is the best way to diagnose if it is the controller that has crapped out? Any ideas on what else can be at fault?

Cheers,

Andreas

Click to expand...

There are a few good posts early on and you might want to go and check what I am saying is the right order
But you can get a multimeter in diode mode and put the black lead on + lead that would go to the battery (battery unplugged) and then probe the 3 phase wires going to the stator and you should see about 0.45V ish if you get 0v/open then one of the fets for that phase is cooked! which you can find by probing source and drain on each fet

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

Click to expand...

have a look at http://www.techbikes.nz/blog/why-bbs02-systems-fail-and-how-to-fix-them/ and the first 15 pages of this thread

seglare86 said:

Hi all,

Apologies if this has been covered in the thread already, have looked through quite a few pages without finding anything relevant.

Tonight when I was going to ride home from work, my BBS02 (new model about 10 months old with the upgraded controller) initially worked fine but after a few hundred meters started to cut out above a certain speed and then stopped working completely after approximately 100m from first symptoms. I was riding in a short slight uphill slope in a low gear and PAS 4 (out of 5) and have done the same ride 100s of times in the same way without any issues.

The display is still working fine but the motor does not kick in at all using either PAS or throttle.

It has been snowing and raining a lot the last week and I guess I might have gotten water (possibly including salt as they have been salting the roads) inside the controller and fried it.

What is the best way to diagnose if it is the controller that has crapped out? Any ideas on what else can be at fault?

Cheers,

Andreas

Click to expand...

Before you start ripping your Bafang apart, disconnect any brake cut-off sensors and see if works.

BBSHD MOSFET versions. There seems to be two versions depending on who the motor comes from. Lectric has specified 3077 and has the 3077's in all motors, and Luna now shows their replacement controllers as IRFB3077. It appears older, earlier this year, Luna BBSHD MOSFET are P75NF. And most vendors are selling motors with P75NF. Perhaps someone can get Luna to reveal when the change happened. I'm not able to post on their forum.

It may be much to do about nothing since the average user will not have a problem with the less expensive P75NF. I haven't picked out any potting on one of mine yet. But soon I'll be changing to a Gearsensor lead version controller and will see what FET's are in my motor purchased in the spring.

I communicated with two vendors who think it's a non issue with the BBSHD.

Hey Guys,

fresh BBS02 500W (with 750W Controller), 48v Motor here.
Everything works great so far, this forum was a great source of information.
One thing i did not notice before (e.g. in Videos ) is a high pitched whining noise coming from the motor.
This sound or noise is always there, light load or high load makes no difference (of course its gone with no load).

I found Timbo925's posting here. Check the last 2 videos in his album here, this is how it sounds.
Unfortunately it is really 'loud' or obtrusive and it gives me a tinnitus, so i hear it even hours later after riding.

The question is, is it normal and if not what can i do to make it less severe?

traiser said:

Hey Guys,

fresh BBS02 500W (with 750W Controller), 48v Motor here.
Everything works great so far, this forum was a great source of information.
One thing i did not notice before (e.g. in Videos ) is a high pitched whining noise coming from the motor.
This sound or noise is always there, light load or high load makes no difference (of course its gone with no load).

I found Timbo925's posting here. Check the last 2 videos in his album here, this is how it sounds.
Unfortunately it is really 'loud' or obtrusive and it gives me a tinnitus, so i hear it even hours later after riding.

The question is, is it normal and if not what can i do to make it less severe?

Click to expand...

I can't hear mine, any of them. Time for a lube job IMO

traiser said:

Hey Guys,

fresh BBS02 500W (with 750W Controller), 48v Motor here.
Everything works great so far, this forum was a great source of information.
One thing i did not notice before (e.g. in Videos ) is a high pitched whining noise coming from the motor.
This sound or noise is always there, light load or high load makes no difference (of course its gone with no load).

I found Timbo925's posting here. Check the last 2 videos in his album here, this is how it sounds.
Unfortunately it is really 'loud' or obtrusive and it gives me a tinnitus, so i hear it even hours later after riding.

The question is, is it normal and if not what can i do to make it less severe?

Click to expand...

Mine makes a similar noise. Has done from new, now over 3000 miles on unit. I kinda like it coz it adds a bit of character to the bike.

I can understand why some owners might find it annoying though. Have packed final drive with grease, although that's not the source of the noise. No plans on lubing up anything else, unless it needs opening up to replace parts.

Its pretty easy to permanently damage your hearing. If its that bad, you need to sort it out and not just keep riding it.

Decent hearing is hard to replace, unlike a replacement BBS unit.

There is running noise from mine, but no where near that level nor is it that whiny. Theres cell phone apps for sound meters available free these days, would be interesting to see what sound level its making.

Yes, agreed, would be interesting to see if a decent dose of lube sorts this out. Sound is usually the most obvious symptom of problems with these units.

Lurkin said:

Its pretty easy to permanently damage your hearing. If its that bad, you need to sort it out and not just keep riding it.

Click to expand...

Yes, agreed, no more rides before i sort it out. I'll ask em3ev if i lose warranty with opening the motor case for greasing. But still, i'm not 100% convinced that it comes from the gears.
I know this sound from electronics like computer power supplies. Bad or cheap capacitors can create a similar noise. So maybe it's the controller at fault.

Lurkin said:

Theres cell phone apps for sound meters available free these days, would be interesting to see what sound level its making.

Click to expand...

I tried to capture it while riding without success, too much wind noise and a bad smartphone microphone does not help here

alfantastic said:

I can understand why some owners might find it annoying though.

Click to expand...

If it were annoying only i had no problem with it. But it's day 2 here and i still hear a ringing in my ears and i'm not even really sensitive on sound. Worked 10 years in a really noisy workplace.

The wining sound in my video's is only noticeable in a silent environment, ones combined with the wind noise I can't here it anymore while driving. Only when the motor is pushing around 400+W I can hear some motor noise. So it does seem like the sound traiser is noticing is something that might be fixable with some extra grease.

Before I go digging up more old threads or start a new one can someone tell me some details about the stock BBS02 PAS sensor?

I’m contemplating an external controller with CAV3 and noticed the Bafang PAS/cadence sensor uses 4 wires. red/black probably 5V but I don’t understand the white/grey wires in the brown PAS plug?

Here’s a thread mentioning those functions connecting to CAV3 - https://endless-sphere.com/forums/viewtopic.php?f=2&t=63072&p=1161458&hilit=third+party+controller#p1161458

That’s promising information but while looking into CAV3 manual PAS I also found reference to settings I don’t quite understand? Stuff like the number of poles? Sensor Type?

Any ideas or guidance to be shared about the BBS02 PAS sensor?

btw, an old 5S RC Lipo balance plug nicely fits the motor Hall sensor connector. Doesn't lock but as long as the pins are tight it's not going anywhere. Especially after sealant or hot glue is troweled on.

Very happy I bought into a supply of JST, Futaba, JR servo connectors and crimp tool. Makes modifying eBikes so much easier, simpler and cleaner with resources to rework similar connections.

I'd be starting with the threads on Keplers work to integrate CAv3.

I think he spent quite some time investigating PAS and how it worked including the sensor...

What benefit are you looking for in an external controller?

chilltrout said:

There are a few good posts early on and you might want to go and check what I am saying is the right order
But you can get a multimeter in diode mode and put the black lead on + lead that would go to the battery (battery unplugged) and then probe the 3 phase wires going to the stator and you should see about 0.45V ish if you get 0v/open then one of the fets for that phase is cooked! which you can find by probing source and drain on each fet

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

Click to expand...

have a look at http://www.techbikes.nz/blog/why-bbs02-systems-fail-and-how-to-fix-them/ and the first 15 pages of this thread

Click to expand...

Thanks a lot, Pulled everything apart and could not find anything that looked obviously wrong or loose. Tried what you suggested above but my multimeter only said "bad" on all phases when I tried it (both with black to + or red to -) and didn't show any voltage.

Have tried in all configurations possible with brake sensors and throttle disconnected etc. and still no reaction at all from the motor. Battery shows fully charged with internal button check and has a voltage of 52v fresh off the charger (it is a 48V batterypack) so do not think it is a battery issue. Display lights up etc. with no problems.

Anyone with any other ideas?

Have contacted the vendor in China (greenbikekit) and they were going to check with Bafang.

Cheers,

Andreas

I know it's frustrating but I'd never own a BBSxx without a spare/backup controller in my kit. It's a very easy motor to overheat and blow a controller. My BBS01 controllers have never been used except for testing and trouble shooting. I have seen a few cases where the connectors inside on the controller were loose and created a problem and fixed by resetting. More often than not this happens with the BBSHD. For the first 6 or so months they used Anderson connectors. Loose connections were more common among those motors.

Empowered cycles sells a trouble shooting kit. All the potentially problem parts and you return the parts that are good for refund.

Greenbikekit has been good about parts, hopefully they will sort you and send a controller. If it is a controller failure I'd review how I ride and shift, I'd suspect lugging and overloading.

BTW I use what I consider the best sealant from JB weld on my mid drive winter bike. ULTIMATE BLACK SILICONE - 3OZ http://www.jbweld.com/collections/silicone-sealants-and-gasket-makers/products/ultimate-black
Incredibly flexible and tough sealant. I wish it were cheap enough to use in building battery packs.

Lurkin said:

I'd be starting with the threads on Keplers work to integrate CAv3.

I think he spent quite some time investigating PAS and how it worked including the sensor...

What benefit are you looking for in an external controller?

Click to expand...

Right on, thanks Lurkin, very helpful.

My motivation for external controller is so that I can run my favorite RC Lipo 16S pack configuration. I really like the physical size and 300Wh high power of 4qty Turnigy 4S 5Ah hardcase. I can do Bafang limitation 12-14S but it’s just an extra PITA in regard to protected bulk charging.

Actually, the reason I dug into the possibility is/was a BBS02 controller failure. My vendor has taken very good care of me with a replacement controller.

But being the paranoid type I became concerned, what if this happens again? So, I happen to have an unused Lyen 6 FET 3077 along with a CAV3 laying around so while everything was accessible I found the BBS02-Lyen Hall/Phase combination and started poking around for the info to wire it all together and program it at some point?

The CAV3 should allow me to “tame” the old Infineon throttle signal enough mimic stock Bafang controller ramp up? Lotsa other cool possibilities with the CAV3 too. Cruise, PAS, Temp protection, etc.

But at this stage, everything’s back to stock and running nicely. I’m just assembling the information needed to prepare a nice plug & play wiring harness. Just in case….

I have a couple BBS02 Lekkie Bling Rings I didn't use in the "used for sale section"

I wanted to report what I discovered mating the Lyen/CAV3 to the BBS02. Plugging it all up was not a problem, very easy. I carefully adjusted the CAV3 THO ramp up and calibrated the actual throttle I used. Phase/Hall found was correct and I was very stoked for a maiden ride!

Rut oh! Old sawtooth controller simply sounds like a “buzz saw”. NOT motor timing, it’s the nasty sawtooth waveform. By the time the sound resonates through the solid mounting of the drive unit into my fairly hard Aluminum Cannondale frame it’s just about as irritating noise as can be… Ugh!

Up side is that CAV3 provided everything I wanted/needed for more of a throttle based bike and I’m sure the PAS would’ve worked out but that damn sound is ugly.

Bafang most definitely using a sine wave controller on these units. Phaserunner would probably be the shit but funds are tight and tighter as my job change approaches.

Oh well, I put back the stock Bafang and I’ve gotta spare and it’s a nice, quiet drive unit. More or less locked into the Bafang way about some things but that’s okay. It's a nicely refined package. Package being the operative word.

Before I go digging up more old threads or start a new one can someone tell me some details about the stock BBS02 PAS sensor?

I’m contemplating an external controller with CAV3 and noticed the Bafang PAS/cadence sensor uses 4 wires. red/black probably 5V but I don’t understand the white/grey wires in the brown PAS plug?

Here’s a thread mentioning those functions connecting to CAV3 - https://endless-sphere.com/forums/viewtopic.php?f=2&t=63072&p=1161458&hilit=third+party+controller#p1161458

That’s promising information but while looking into CAV3 manual PAS I also found reference to settings I don’t quite understand? Stuff like the number of poles? Sensor Type?

Any ideas or guidance to be shared about the BBS02 PAS sensor?

btw, an old 5S RC Lipo balance plug nicely fits the motor Hall sensor connector. Doesn't lock but as long as the pins are tight it's not going anywhere. Especially after sealant or hot glue is troweled on.

Very happy I bought into a supply of JST, Futaba, JR servo connectors and crimp tool. Makes modifying eBikes so much easier, simpler and cleaner with resources to rework similar connections.

Click to expand...

Ykick said:

Bafang most definitely using a sine wave controller on these units. Phaserunner would probably be the shit but funds are tight and tighter as my job change approaches.

Click to expand...

THANKS for that! I had the same bits in the parts box and now I don't have the struggle and the wonder.

newjazz said:

Hello,
I have a bafang bbsHD that is only 4 months old and I am loving it. However a few days ago I noticed some drag when pedalling and without notice the system would shut down, no error codes and will only come back if I recharge my pack!
I am not exactly sure if it is a battery problem too because my 13s7p 30q pack read 46v from by multimeter when the cut off happens. Even crazier, Now I only get 30 to 40% range ! Any suggestions out there as to what my problem is?.....
Thanks,*

Click to expand...

Did you ever figure out what the problem was?

JTL said:

newjazz said:

Hello,
I have a bafang bbsHD that is only 4 months old and I am loving it. However a few days ago I noticed some drag when pedalling and without notice the system would shut down, no error codes and will only come back if I recharge my pack!
I am not exactly sure if it is a battery problem too because my 13s7p 30q pack read 46v from by multimeter when the cut off happens. Even crazier, Now I only get 30 to 40% range ! Any suggestions out there as to what my problem is?.....
Thanks,*

Click to expand...

Did you ever figure out what the problem was?

Click to expand...

His is a homebuilt pack.