Bafang BBSxx - fault finding and fixes

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Ben Abraham   100 µW

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Re: Bafang BBSxx - fault finding and fixes

Post by Ben Abraham » Oct 11 2017 10:13pm

I went ahead with the Quiksteel solution (technically it was a JBWeld steel stick). It works! At least for now... I took it out for a spin last night and rode it in to work today without problem. I hadn't realised how noisy the thing had gotten! Silent as a ninja now.

To true it, I removed the stator, applied the epoxy, set it in the bearing covered by clingwrap to prevent it from bonding to the bearing... This yielded a built-up axle with 7.8-7.9 mm diameter. I put it in the case without the stator with both rotor ends in their bearings and the case screwed shut to keep it true while the JBWeld cured. When I rebuilt motor I applied Locktite 609 to keep it in the bearing. It seems to work fine -- the only issue is that the freewheel seems a bit less free than it was... but this can't be the rotor because both the shaft and nylon gear clutch will be disengaged for this action. The bike performs better than it did when the problem was diagnosed. If a problem emerges with the bearing later on, then I'll cross that bridge then.

I'm amazed by how quiet it is now!

Thanks, everyone! :D

Ben Abraham   100 µW

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Re: Bafang BBSxx - fault finding and fixes

Post by Ben Abraham » Oct 11 2017 10:15pm

Oh, yeah and I took the opportunity to Mobilegrease 28 the whole thing. Should I have greased the clutch? I did... is this why it's a bit more viscous-feeling?

I got the motor from Emax-Ebikes back in 2013. Definitely, absolutely, positively out of warranty.

Still no contact from GBK about spare parts and the order is still "processing". If I don't hear from them by the end of the week I'll probably go to PayPal and yank the order.

Ben Abraham   100 µW

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Re: Bafang BBSxx - fault finding and fixes

Post by Ben Abraham » Oct 11 2017 10:17pm

Whoops! Check that... GBK did send the order and now I have a tracking #. Apologies for the mix-up; I didn't see the email at first...
Probably should have ordered a spare bearing just in case... ah well. If it gets here OK then I'll keep them in mind in the future and get it in the next round.

tomjasz   1.21 GW

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Re: Bafang BBSxx - fault finding and fixes

Post by tomjasz » Nov 10 2017 12:23pm

Lurkin wrote:
I will get round to posting up the grease docs from Bafang when I get time.

Any hope for the curious?
Thanks Justin_le we're here thanks to you. All the best to the mods for their tireless work keeping it on an even keel.

spockie   1 mW

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Re: Stuck on assist 1 & display buttons unresponsive.

Post by spockie » Nov 20 2017 10:38am

I have a dead C961 display and cannot power up the motor. Absolutely no response from the power, + and - display buttons.

I'm able to program the motor controller using PC software and programming cable and so can confirm communication with the motor is OK. I checked the cabling for any insulation wear and went through reinserting all the plugs to make sure it made proper contact. Also checked the battery output which is around 40V. I have now disassembled the display unit and replaced a button CR2032 battery as it was slightly corroded. I used a meter to check for continuity to the buttons and plug and all tested fine.

Some background information before this happened. I previously had an intermittent fault with the C961 display where it was stuck on power level 1 which suddenly cured itself and working fine for many weeks. However lately it has been difficult to power up and took several attempt to work by disconnecting and connecting the battery. With the current fault, I noticed when switching off the battery by the switch, the switch light remains on for a few seconds before distinguishing.

Before I buy a new display unit, I wonder if anyone know what might be the cause of the fault.

Lurkin   100 kW

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Re: Bafang BBSxx - fault finding and fixes

Post by Lurkin » Nov 20 2017 3:31pm

Water ingress is typically what kills these screens and causes intermittent faults with them.

spockie   1 mW

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Re: Bafang BBSxx - fault finding and fixes

Post by spockie » Nov 20 2017 4:32pm

So is likely it's the display that's faulty. When I looked inside the display it seems dry and unable to find or smell any burnt component.

Lurkin   100 kW

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Re: Bafang BBSxx - fault finding and fixes

Post by Lurkin » Nov 20 2017 8:45pm

Leave it somewhere where it would definitely dry out even if you cannot see it for 12 hours or so. Then plug it in, see how you get on. If that not it, I would be inspect the plugs and using a multimeter to ensure continuity on each part of the loom.

I never got round to trying to repair my display. Totally possible to use these units without the display and relying on the default settings of the motor controller to power/instruct the motor unit, which is what I have done since.

I started a project to investigate replacing the display unit with something more universal/ swap it out for just buttons and a more simple display but never finished it. There is a german pedelec site where they have achieved this but I never got a response out of them. They have produced a homegrown cycle analyst device to replace the display altogether.. may give one of these a go in the future. Advantage being, you can choose the display it interacts with rather than being required to use non waterproof king meter displays like this one.

spockie   1 mW

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Re: Bafang BBSxx - fault finding and fixes

Post by spockie » Nov 21 2017 6:24pm

Lurkin - That's an interesting project you started, shame you never finished it. I was thinking maybe just the buttons and a 7 segment display to display PAS level for a minimalist look.

Back to my problem, I searched this forum for a dead display but didn't find anything conclusive. However I stumbled onto a thread about using the motor without the display and found more information at this sitehttp://www.poweredride.com/info/dump-yo ... ay-options. Basically it involves shorting the PL and P+ pins on the plug that connects to the display. Since I already have a programming cable which have this, I plugged this in and hey presto, my bike came back to life. :D

Is now obvious that my display is faulty and I'll have to order a new one. Had a brief test ride and found I don't miss the display except for changing PAS level and would be great if a solution existed for this type of setup.

spockie   1 mW

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Re: Bafang BBSxx - fault finding and fixes

Post by spockie » Nov 21 2017 7:04pm

My prayer may have been answered. While searching for the best deal for a C961 display on Aliexpress, I come across module with buttons and leds https://www.aliexpress.com/item/Free-sh ... eLevelAB=0

It seems only 5 PAS are available, there's no manual available so short on information. Think I'll start a new thread on this for better visibility.

Lurkin   100 kW

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Re: Bafang BBSxx - fault finding and fixes

Post by Lurkin » Nov 21 2017 8:52pm

Thats perfect and pretty much exactly what I wanted after being in an identical position to you. Interesting, pretty sure the same guys used to sell a (appearingly) knock off kingmeter screen which was cheaper than the correct replacement. Nice man, are you ordering one of these? Otherwise I may have to... 8)

spockie   1 mW

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Re: Bafang BBSxx - fault finding and fixes

Post by spockie » Nov 22 2017 6:44pm

I'm now not too sure whether to get the new DPE-12 led display. If there is a fault condition in the motor. normal LCD display would display the appropriate error code, I can't see the DPE-12 would do this. From people's experience in fault finding, is the error code vital to this?

bretster   1 µW

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Re: Bafang BBSxx - fault finding and fixes

Post by bretster » Jan 31 2018 11:52am

I have the dreaded growling gear noise on a 500w 36v BBS02 with about 3000km on it. I ripped it apart and all the gears are fine. It appears the motor shaft is the problem as it measured 7.9mm, but on the GEAR side, not the motor side. The motor side also feels a little loose, despite measuring 8.0mm (just using calipers...not very accurate). Has anyone had this problem on the gear side and used Loctite to fix it? I am thinking I might need to loctite both ends, which would mean possibly never being able to open it up again. Any ideas that don't involve loctite on both ends?

Thanks for any information you might provide!

Bret

heathcliff   100 µW

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Re: Bafang BBSxx - fault finding and fixes

Post by heathcliff » Apr 04 2018 4:04pm

bretster wrote:
Jan 31 2018 11:52am
I have the dreaded growling gear noise on a 500w 36v BBS02 with about 3000km on it. I ripped it apart and all the gears are fine. It appears the motor shaft is the problem as it measured 7.9mm, but on the GEAR side, not the motor side. The motor side also feels a little loose, despite measuring 8.0mm (just using calipers...not very accurate). Has anyone had this problem on the gear side and used Loctite to fix it? I am thinking I might need to loctite both ends, which would mean possibly never being able to open it up again. Any ideas that don't involve loctite on both ends?

Thanks for any information you might provide!

Bret
Hi Bret,

That is precisely what happened to me after my first overhaul at 1500kms. The next year, it started to make that noise when the motor was heating up. With the motor cool, it was utterly silent. After a moderate to strong effort, the noise started again. I only made 500 kms so far that year so it wasn't normal.

Note that it's a BBS02B so it's completely different that the BBS02.

In the BBS02B, the bearing on the motor side is already loctited to the rotor at factory otherwise tolerances has changed and the fit is extremely tight. So I never tried to separate them. If it ain't broke, don't fix it. I did applied yellow loctite though between the outer side of the bearing and its casing.

See photo where the bearing is stuck to the rotor: https://www.ts-export.com/_mb/bbs02_31d ... GP0378.JPG

For a good measure, I applied yellow loctite as well on the both sides of the gear side bearing effectively locking everything into place.

I applied a small amount of loctite, so with some prying force or heat from a torch, the motor could be reopened.

It's deadly silent since and I made 2200 more kms afterwards.

Hope that helps.

Sorry for the delay in replying, I thought that thread was dead.

mclark999   100 W

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Re: Bafang BBSxx - fault finding and fixes

Post by mclark999 » Jun 14 2018 6:18pm

Just wanted to share my experience and ask some repair questions.

I have a 750 watt BBS02 built in October 2014. I've run it for over 2600 miles (over 4000 km) and it's been trouble free. I did make a programming cable for it and set the max current to 18 amps and I only use it with pedal assist. I ride it on a hybrid for commuting and with the exception of a couple of small hills, it's a pretty flat commute. I occasionally run it up to 850 watts but most of my riding has been at 200-500 watts. I downshift when I stop so I rarely start out in a high gear.

I recently started getting a bit of a clunk when I start pedaling and assumed the freewheel or clutch was going bad so I opened it up today to take a look. The only issue I found was the main metal drive gears didn't really have any grease on them any more and there were a bunch of very fine metal filings in the case, probably from running dry. The nylon gear looks perfect and had plenty of grease. I even had a good silicon washer between the two nuts that hold the crank in. Aren't I lucky?

So I'm going to grease the main gears, repack grease (lithium) the nylon gear and put it back together. And I'll clean and grease the thrust bearings on the crank. Here are my questions.

1) Do I need to repack the needle bearings that the crank rides on? And is there an easy way to get them out to clean them? Is that needed?

2) Do I need to reseal the controller bits between the motor and the controller with silicon like it came from the factory? I'm assuming they are all sealed up to keep the grease out of the controller side.

3) After packing the gears well with grease, do I need to take it apart again in a thousand miles or so and repack or will that not be necessary if I do a good job with the packing?

4) Does the clutch/freewheel on the crankshaft need a bit of grease in it? It seems to be working correctly, it just makes a clunk each time I start to pedal.


5) What's the most miles anyone has put on a motor without replacing any of the gears or bearings?

Thanks for the assistance and safe and happy riding to you all.
-------------------------------------
Sikk Bikes cruiser with 66cc China girl
Trek FX 7.2 with Bafang BBS02 750W 20A
Trek 5500 with human power
Giant Trance with human power

dustNbone   10 kW

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Re: Bafang BBSxx - fault finding and fixes

Post by dustNbone » Jun 14 2018 9:37pm

Make sure the motor is tightly mounted in the bottom bracket. The only time I've noticed a bit of a clunk was when the motor was moving slightly, and bumping into the frame as the driveline loaded up.

If you grease the gears well you're probably good for several thousand miles, make sure the seal on the cover (and the surface it mates to) is clean when you put it back on afterward. I've done the grease 3 times in the 2+ years and over 25,000km I've had my BBS02, once when it was brand new and during annual service since then. No noticeable wear on the gears last time I looked at them.

mclark999   100 W

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Re: Bafang BBSxx - fault finding and fixes

Post by mclark999 » Jun 15 2018 11:30am

Thanks. That's a lot of mileage. Good to know it should last much longer. I'm glad I took it apart when I did.
-------------------------------------
Sikk Bikes cruiser with 66cc China girl
Trek FX 7.2 with Bafang BBS02 750W 20A
Trek 5500 with human power
Giant Trance with human power

staldor   10 mW

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Re: Bafang BBSxx - fault finding and fixes

Post by staldor » Jun 18 2018 1:11pm

Hi

Does anyone recognize the following problem?

While biking I will suddenly loose my motor power. Before this the battery indicator will normally loose a step before suddenly going down to zero. Then the battery symbol will starts to blink (as shown in the attached video). The battery shows a steady 50V, so it does not seem like a battery problem, more like a controller problem. After a while (couple of seconds to several minutes) the battery indicator will suddenly go back, and the bike starts to work again.

https://photos.app.goo.gl/FrTidzbcaA2D21Eb6

Animalector   10 kW

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Re: Bafang BBSxx - fault finding and fixes

Post by Animalector » Jun 18 2018 8:54pm

could be a single dead cell in the pack, causing the Low Voltage Cutoff on the Battery Management System to cut power to the entire pack.

The battery voltage will read high (because most of the cells are still good, but that one bank is low..

Example for a 10S pack could be:
3.5, 3.5, 3.5, 3.5, 2.6, 3.5, 3.5, 3.5, 3.5, 3.5 = 34.1V (but will trip under load)

Usual cause is 2 of the 3 parallel cells has failed welds or solder joins.

Open the pack to inspect.

Good luck.

staldor   10 mW

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Re: Bafang BBSxx - fault finding and fixes

Post by staldor » Jun 19 2018 2:16am

Thanks for the reply!

But should I not notice this battery issue with a multimeter? I first suspected the battery, but I can't figure out how this error can be transmitted from the battery to the controller, when it is only connected with two leads (50 V).

If the display shows 0 battery power while I read 50V on the battery, for me it sounds more like a controller issue (I tried a new dispaly, which did not fix the problem).

Animalector   10 kW

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Re: Bafang BBSxx - fault finding and fixes

Post by Animalector » Jun 19 2018 2:24am

So the controller is not turning off? I misunderstood. Will it could be a poor joint. In one of your connectors. See if you can measure the backs of the connectors with a multimeter

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Re: Bafang BBSxx - fault finding and fixes

Post by staldor » Jun 19 2018 6:39am

Yeah. That is a good idea. But I guess I test most of the connectors when attaching a new display module?

I found a new controller ( I had several controllers failure due to what I belive to be rain/snow/salt issues). I will try to change it tonight.

Currently I can bike for 2-3 minutes before the battery indicator goes to zeros. Then I need to wait for another 2-3 min before it works again. This could maybe be caused by the BMS (battery management system inside the battery) which turns the battery off for a short moment (due to cell failure). And though the battery turns on again relatively fast, the controller have a built long delay respons before it turns it on again. Not sure if anyone know how this controller is programmed?

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Re: Bafang BBSxx - fault finding and fixes

Post by Drum » Jun 19 2018 2:48pm

I have seen similar issues caused by bad contact between the battery and its base (with a removable battery). Might pay to check for signs of corrosion or heat around the battery terminals also, if you haven't done that yet.
I found in that case that there were two pairs of contacts between the battery and the base. Both were live on the battery (two positives and two negatives), but in the base only the outer pair were connected. After soldering a link wire between the inner and outer contact of each pair in the base, there were no more issues.
Good luck finding your problem.

tomjasz   1.21 GW

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Re: Bafang BBSxx - fault finding and fixes

Post by tomjasz » Jun 20 2018 2:51am

If you can find spare parts do it now. Old versions are getting tough...
Thanks Justin_le we're here thanks to you. All the best to the mods for their tireless work keeping it on an even keel.

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Re: Bafang BBSxx - fault finding and fixes

Post by tomjasz » Jun 20 2018 2:53am

sannder wrote:
Mar 26 2017 8:25am
Animalector wrote:Check your start current settings
I did. I increased from 10% to 20% and the juddering become more subtle.

However, after some tests, I noticed that this behaviour is intermittent.
Motor starts well and at about 40rpm there is some "hesitation". It's always in that region.
Most of the time is not even noticeable, but sometimes (on a steep hill) the effect is more pronounced.

Finally, I increased the Keep current a bit and let the start current to 10% as I like a smooth kick.

Start current: 10%
Slow-start: 4
Start degree: 4
Work mode: 10
stop delay : 250ms
current decay: 5
stop decay: 0
Keep current: 70%

For me the smoothness was one of the reasons why I switched from BionX to BBSxx.
I am considering swapping the controller with a BBS02B one or replace the whole unit.

ps: I am running 11S on this controller and with 10S the problem was actually worse.
Voltage sag is minimal, and I use the gears correctly.
Older motors cannot use 02B controllers. I had a hard time finding 01 controllers.
Thanks Justin_le we're here thanks to you. All the best to the mods for their tireless work keeping it on an even keel.

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