Bafang BBSxx - fault finding and fixes

[teslanv]

Hi all,

So my Bafang BBS02 750W started making some terrible noises last week. I took the motor apart and sure enough the bearings on the shaft that holds the teflon gear in place have failed and there were metal fragments throughout. Does anyone know if it is possible to buy a rebuild kit? OR even just the bearings?

Sad and it happend after only 700km....

Thanks

Sounds ugly. Any pics you want to share?

I know you can get replacement Nylon gears, and bearings are probably somewhat standard items. I guess it depends on how much other damage was done in the motor...

 

[Kepler]

There is a similar failure and repair path documented earlier on in this thread that should help you with the rebuild.

 

[Tom L]

I fitted a new controller from cellman today. I ordered the 25A 9 FET but it seems to be limited to a maximum of 20A under load. The same wattmeter and battery peaked at 25A with my first controller.

The programmed parameters list a 25A current limit and everything else seemed sensible apart from a rather high start current (40%).

Using the software the hardware version is listed as V1.1, Firmware V1.0.0.1, 48V, 25A. Anyone with a new controller able to compare this?

 

[untilsummer]

Hi, thanks for the replies. Unfortunately, I'm in a small apartment so I have to put everything back together after I take it apart or else, no dinners until the next weekend....

So I've read through a good bit of the referred thread and various other sources but I still can't figure this one out. When I opened the motor because of the obvious failure noises, there were 6-8 ball bearings floating around, some mangled rubber type ring (in pieces), and two metal rings, one mangled and in pieces and the other still in one piece. The picture is of the one that was still in one piece. At first I thought it was a thrust bearing but now I'm pretty sure it wasn't, the ring has a bit of a bevel whereas the other thrust bearings in the motor are different. It came out from the nylon gear chamber area.

Any idea what type of bearing it is? Or better yet, where I can buy it?

Thanks!

 

[beazee]

Hi there, didn't manage to thread through the whole thread, was stopped at the page 5.
If this fault was mentioned before and successfully fixed - be excused - I shall find this in the coming hours, browsing through the thread.

Motor: BBS-01 36V 500W 25A
Bought: Feb 2014 (8 months ago)
Series: 140311xxxx
Mileage: 2,375 kms (3,500 km annual)
Battery: 10s5p Samsung 26f cells
Bike: LvsH Bullitt Cargo Bike
Commute: daily commuter to/from work (11 kms), 3/7 extra school runs with pax (18 kms),

Symptoms:
- lack of power, can no longer "boost" by pressing the thumb throttle
- lack of power, got back in line with other cyclists, the retired ones particularly
- thumb throttle stopped working, sometimes rotates the chainring by 3' angle, stops under load, othertimes not even up to rotate the crank,
- 'pedestrian mode' working OK (load / no load)
- PAS 5/5 getting the rear wheel up to speed (~55 km/h) under no load (wheel up in the air), smooth
- PAS 5/5 under load allows for cruising at 22 km/h (used to be >38 km/h), jerky
- PAS 5/5 max current 9A under load (commuting), used to be ~15A, jerky
- PAS 3/5 max current 9A under load (commuting), used to be ~9A, jerky
- display works as usual, no error codes, no flicking or shutting off
- resetting the system by turning the display off/on and/or the battery off/on doesn't work.

All of the above happened once (Thursday last, lasted about an hour) then everything got back to normal.
Hit again today - no amount of restarts, rests switched off seems to help.

Few charts from Speedict Mars:

How it used to be - throttle boost, up to 23A

How it used to be - PAS 5/5, 16A max

Now - PAS 5/5, 9A max, jerky, very irregular pattern, starts, reaches peak current, shuts off, restarts. Speedo sensor is dead - don't bother.

Now - PAS 3/5, 9A max, assists @5A for longer times, periodically shuts off, not as jerky. Speedo sensor is dead - don't bother.

Any ideas / fixes most welcome.
I don't even know where to start.

================================
(23/10/14)
Disregard the above.
This is definitely a NuVinci hub fault.
Less than optimal amount of oil inside the hub stalls the hub in the highest "gear" setting.

===============================
(24/10/14)
Must be something else. As the above assumption was proven wrong this morning.
Battery charged up over night. Connected. One leg of the commute covered no issues.
Trouble started on return:
- lacking power (no matter of NuVinci gesr setting) to no power when battery display shows "full",
- display showing "full", throttle down, LCD down to "none", throttle released, LCD back to "full" and again..,
- After hard restart - "full" as long as not peddling, on crank turn - "none", shuts down.
- Restart... and so on...
- up to the moment where the error code appeared on the display "Err 30"

0x30 communication has problem

Got to recheck the connections.

Found in the mainthread:

reddit member "anontrol" has reported that he bought two of the BBS02 units direct from China (through Ali-XX?), and has reported that both of them have a defective controller. The bad units are marked "C950 V4.0", though I suspect the version type is not a bad design so much as middle-men are selling factory QA reject units through third parties.

http://www.reddit.com/r/ebikes/comments/1xd06b/warning_defective_bbs02_48v_25a_bafang_8fun/

One of two C961 displays I got with 750W BB-02 kits started showing only "er 30" message ~2 seconds after booting :? , which a rep tells me means "communication problem" (fyi, that error message is not listed in motor or display manuals). Doesn't affect motor performance, but I can't see speed or PAS level since the error message takes over the display screen.

Same rep says C961 is "very reliable". But when I swapped out with my other identical display it worked fine. Ergo the problem is with that first display I'm sending it back for the 8Fun/Bafnag techno-wizards to diagnose. Hopefully a new warranty replacement display will be forthcoming but I'm told C961 has been replaced/upgrade/had pigtail changed rendering my older one obsolete since the new display (& maybe harness) connectors are all different.

I know my <Nov. '13 all-black harness was since upgraded by 8Fun/Bafang to a multi-colored harness.

Is it a faulty display then?

=======================
Another suggested fix:

remove the C961 silver battery to force a reset. (...)
I mean opening the C961, remove the little 3V battery, wait a couple of minutes and refit or replace the battery.

Migth try that one before putting an order for a new display.

 

[beazee]

.

 

[beazee]

.

 

[Tom L]

Where are you measuring your battery voltage for the graphs?

First thing I'd be checking for would be battery voltage drop across the main battery connectors. Could be a bad connection.

 

[beazee]

Hi Tom,

Speedict was plugged in between the battery and the motor.

I have since removed it and rechecked the following connections:
- battery-motor,
- LCD-motor,
- thumb throttle-motor

I've finally got a confirmation from Amy (General Electronics Battery) that the case was escalated to the Engineer and they should get back once they have found the definite culprit.

================ (Update: 29/10/2014)

They seem to be as clueless as I am.
Was asked to record a video. Not even telling me what should I focus on first place.

============= (Update: 30/10/2014)

LCD Display died.
Switched on -> battery "full" -> few tests with throttle and PAS (unsuccessful) -> battery "empty" -> switched off, unable to switch it back on.
The battery was full (unable to check the voltage right now).

 

[mclark999]

My 750w BBS02 built in June doesn't freewheel easily. If the motor isn't going, it's hard to pedal and theres a gear whining like noise coming from inside the motor housing. Other than that, everything works fine. Thoughts on how/what to repair?

 

[Kepler]

Sounds like the sprag bearing on the intermediate gear has locked up. Try holding on to the chain ring and spinning it backwards with a jerk. This might free up the intermediate shaft from the sprag bearing. If that doesn't work, you will need to dismantle the drive and possibly replace the intermediate gear and sprag gearing assembly.

 

[beazee]

Placed an order for new controller and the replacement LCD display with Moon @ em3ev, hopefully replacing these will fix the issue:
https://www.youtube.com/watch?v=p-d1BMlLroU

 

[Aushiker]

Went to ride to work this morning and no power.

Current situation is that my charger fan (I believe it is a 42V 2.5A,10S ex EM3EV charger] is not working this morning but the lights are coming on showing that it is charging and a check of the output suggests it is putting out 42.7 volts, so I assume it is working despite the fan not doing anything. Sound reasonable?

Now the battery is more of a concern. It is a 36V Samsung Frame Mounted Pack (10.25-16.5Ah) - Configuration: 10S 6P, 29E cells, 36V, 16.5Ah from EM3EV. I put the volt meter on the output connection and I am getting a reading of 1.2v.

I currently have it on charge but need to go to work so will not be able to check if it was simply a flat battery issue until I get home. Does it sound like a flat battery issue or something worse?

Thanks
Andrew

 

[teslanv]

Check the blade fuse in the frame pack. Other than that,
I actually repaired the fuse holder in one of the frame pack cases when it went bad.

 

[Aushiker]

Check the blade fuse in the frame pack. Other than that,
I actually repaired the fuse holder in one of the frame pack cases when it went bad.

Thanks. It turned out to be a fuse issue but I am not sure what exactly. I pulled the fuse out and it was okay and put it back thinking I will have to take the case off and investigate further. Before that I did a voltage check and bingo it is back to 41.7 volts so all good.

Thanks for your help.

Andrew

 

[dan974]

Hi everybody, I mount BBSO2 for a guy on a 29" ,750W 25A last design (01/10/2014), here are the troubles (sorry for my english)
if I can trust the guy ...he said he could not keep hand on the motor, hand and it cut after returning a 300m hill climb in which the throttle was not able to give more power...and he used mode 7...
not throttle, no PAS...everthing ok, magnest red light ok, brakes removed nothing more...
C961 display no errors sometime ER08 (halls ?) , I think he used full throttle like 30% in a wrong with a 14T sprockets on 7SPeed...

WOULD plz confirm that the controller is overheating protected ? what is cutting temp ?

I did not open yet, but maybe it's only a loose hall cable inside.

best regards

 

[KINNINVIEKID]

You are correct.
There is a cut out to protect against overheating.

 

[dan974]

I can add that the front sprocket is difficult to turn in reverse and feeling like there is grits...disappear when I disconnect one phase, I interchange with a nother controller, motor spine, tested shorten phases motor is impossible to reverse turn by hand.

when it overheat, does it cut or does it just write an error code ?

 

[Tom L]

Check the blade fuse in the frame pack. Other than that,
I actually repaired the fuse holder in one of the frame pack cases when it went bad.

Thanks. It turned out to be a fuse issue but I am not sure what exactly. I pulled the fuse out and it was okay and put it back thinking I will have to take the case off and investigate further. Before that I did a voltage check and bingo it is back to 41.7 volts so all good.

Thanks for your help.

Andrew

You might want to think about replacing that fuse holder. Something similar happened to me. A couple of unexplained intermittent power losses then a day later no power at all. The fuse was intact but the holder had melted because of the heat generated through poor contacts. The blade fuse holder used in the bottle mount battery packs is cheap junk. It's not up to the vibration and current. Go to an auto parts store and check out the contacts in the in-line versions. The quality varies a lot.

 

[darth_elevator]

Here's a puzzler for you guys.

Yesterday hie2kolob got Error 30. We searched error 30 and found this behavior similar -- at powerup, the display comes on and the battery symbol flashes momentarily like it always does, but then the entire screen goes blank except for the "Er 30" message. This is a BBS02 with C961 display. After checking all the connections and not finding anything amiss, we mixed and matched with my working system. Here are the combinations we tried, with the puzzling results:

His Motor/Controller + his display = Error 30
My Motor/Controller + my display = Works fine
My Motor/Controller + his display = Error 30
His Motor/Controller + my display = Error 30

I would have thought that mixing and matching the working system with the non-working system would have yielded an error in only one of the combinations, not both. Does this suggest that something got fried on both the display side and the motor/controller side? Or does it more likely suggest my display and controller are on a different firmware version than his, and thus will always yield Error 30 when we mix and match, even when both halves of the combination are fine?

 

[cwah]

Hello,

I'm having error 21, which I understood is speed sensor. And sometime when it's raining the bike automatically starts and ebrake doesn't always work.

Any help? Thanks

 

[Tom L]

I would have thought that mixing and matching the working system with the non-working system would have yielded an error in only one of the combinations, not both. Does this suggest that something got fried on both the display side and the motor/controller side?

Yep.

 

[darth_elevator]

Thanks, Tom

 

[beazee]

The saga continues:

Controller + display arrived (em3ev).
Had enough time only to swap the display and the error continues - thus not a display fault.

Will swap the controller later today.

Also the email arrived form Amy (GE Battery) - they suspect it's the faulty controller.

-----------------------
PROBLEM SOLVED!

Although hard to admit but here it is - I'm an idiot. What's the stupidest thing I could do?
Well - I fried the connectors. And it was ALL that prompted the multitude of errors.

When checked I focused on the battery side connectors (and got them replaced) and forgot the other pair down the line, towards the motor as the motor wire wasn't long enough.
All covered in the heatshrink tape - didn't brought my attention.

Until actually the day I swapped the controller. The carnage:

3-line wire is the temperature sensor for Speedict Mars.

-------------------
Interesting thing with the new controller - this one is restricted and obeys the limits set on the display.
Previous one was unrestricted no matter what was set on the display.

 

[cwah]

I've now changed to a new cassette and chain. It all almost work fine.

The front chain sometime fell off while riding. It happens most of the time when I change gears.

Would that be because the chain isn't properly tensioned?
Or maybe i need some front chain alignment guide?