Bafang BBSxx - fault finding and fixes

[liontail]

Thanks for the response, Tomjasz! Controller actually came with just 3 PAS levels. I just opened it to the full 9, and still the same behavior... anyone else ever experienced something like this? Or heard about it?

My suspicion is that it has to do with shortening that 8 pin cable somehow... thoughts? Are the color codes maybe different before and after the 8 pin waterproof plug, which I bypassed?

[tomjasz]

I think you just diagnosed your own problem. A short or a problem you created splicing...
I just put yp with a slightly unsightly connection. I thought I'd like to shorten as well. Watching the out come...

[Tom L]

Liontail, check out Kepler's latest posts in the programming thread to eliminate cogging/pulsing at low rpm. You will need to adjust the way your controller is programmed.

[liontail]

Thank you Tom L! I had a feeling that this issue wasn't a splicing problem. As Kepler said in the programming thread,

One thing that i did notice is the new drives seem to be more prone to cogging if you take off in to harder gear. Easy to ride around but worth keeping in mind.

Reading on, I guess cogging is exactly what I'm describing. The problem isn't terrible - you can certainly ride it, and smoothly if you use the throttle at low RPM - but it is far from ideal.

I was very glad to see that the programming cable plugs into the display port, and not the 8-pin port that I cut out of the system!

I'll have to trawl through the 18 pages tomorrow to figure out how to mock up a proper cable. Thanks for all the replies.

[tomjasz]

I'll have to trawl through the 18 pages tomorrow to figure out how to mock up a proper cable. Thanks for all the replies.

or just read pexio,

http://endless-sphere.com/forums/viewto ... io#p915172

[redcliffs-rider]

If you do not want to make your own cable, you can buy a ready made - but expensive - one on AliExpress.

http://www.aliexpress.com/item/8fun-baf ... 39445.html

Paul

[tomjasz]

If you do not want to make your own cable, you can buy a ready made - but expensive - one on AliExpress.

http://www.aliexpress.com/item/8fun-baf ... 39445.html

Paul

http://www.aliexpress.com/item/8fun-baf ... 39445.html

OUCH! $65USD!

[joshseitz]

I just posted some pics of my Cannondale prophet build over in the main Bafang Crank Drive area, but I thought I would post these issues here too:

1. Twice it took-off while standing over the bike. I wasn't touching the throttle and I don't believe I bumped the cranks, engaging PAS. I believe PAS requires a bit more than a bump to engage, and it felt like full throttle. The front-end rose right off the ground, but I managed to grab my back brake in time to prevent it from flipping right over. I now leave the bike off while mounting and dismounting and just turn it on when I'm ready to ride. If anyone else has experienced something like this, and particularly if you know of a possible cause, please let me know.

2. I purchased two "universal brake sensors" from Lectric Cycles so that I could retain use of my hydraulic levers http://lectriccycles.com/products/unive ... drive-kits. I mounted the sensor to the lever body and taped the magnet to the actual lever for testing. When I squeeze the lever, the motor goes dead for several seconds and the display reads ERROR 30. Once or twice it flashed ERROR 4 before reading ERROR 30. Once I release the lever and wait for several seconds, the drive returns to normal operation UNTIL you use the brakes again. I tested both sensors with the same result. The factory levers work fine and don't throw an error. Any ideas?

Aside from the issues above and suspect programming, I'm stoked about this thing.

[teslanv]

1. Twice it took-off while standing over the bike. I wasn't touching the throttle and I don't believe I bumped the cranks, engaging PAS. I believe PAS requires a bit more than a bump to engage, and it felt like full throttle. The front-end rose right off the ground, but I managed to grab my back brake in time to prevent it from flipping right over. I now leave the bike off while mounting and dismounting and just turn it on when I'm ready to ride. If anyone else has experienced something like this, and particularly if you know of a possible cause, please let me know.

Pretty sure the issue is the sensitive PAS. I either keep my hand on one of the brakes or turn it off completely to avoid this.

[tahustvedt]

What's even more fun is accidentally appling full throttle as you are about to straddle the bike with the rear rack full of groceries. I spun around as the bike drove around me while I held the handlebars. Felt very silly when that happened.

[tomjasz]

Oops, just once. That was enough.

[rpgear]

Just installed a BBS01 350W 36V C961 Display and turned the unit on. Came on momentarily and then displayed a blank screen with er 8 at the bottom. Configured the system including wheel size, number of PAS settings (9) and plugged in the thumb throttle and brake levers. Speed sensor blinks red when passing the magnet.

A test ride in any PAS setting resulted in no power. Thumb throttle - no power. Display indicated full battery, speed and distance as I pedalled. No heating of motor or wires.

An email to Bafang came back that error code 8 is a problem with the internal hall sensor. She then said she would get back with me with a solution. That means next week now.

Anyone come across this? This is a new unit out of the box. Customer (my wife) is waiting very impatiently...

[tomjasz]

Just installed a BBS01 350W 36V C961 Display and turned the unit on. Came on momentarily and then displayed a blank screen with er 8 at the bottom. Configured the system including wheel size, number of PAS settings (9) and plugged in the thumb throttle and brake levers. Speed sensor blinks red when passing the magnet.

A test ride in any PAS setting resulted in no power. Thumb throttle - no power. Display indicated full battery, speed and distance as I pedalled. No heating of motor or wires.

An email to Bafang came back that error code 8 is a problem with the internal hall sensor. She then said she would get back with me with a solution. That means next week now.

Anyone come across this? This is a new unit out of the box. Customer (my wife) is waiting very impatiently...

I made a rather protracted search, with the poor native engine, and found nothing. Neither did an exhaustive google search, limited to english.
Where are you located, perhaps you would be lucky enough to have another user near by and find that it is a C961 problem. I didn't have error code 8 but I had an intermittent run problem with the bottom quarter of the C961 reading blank. A new 961 solved it.

Who did you buy from and where are you? Also could you share the serial numbers from the motor and controller sides? It may help others and current users to have an idea when the problem units were built.

Thanks and good luck!

Tom

[teslanv]

Another possible cause of the turn on and then blank screen could be a poor battery connection. Check the wires and connections to the battery to confirm you are getting a solid connection with proper voltage between 42V-60V.

[rpgear]

I made a rather protracted search, with the poor native engine, and found nothing. Neither did an exhaustive google search, limited to english.
Where are you located, perhaps you would be lucky enough to have another user near by and find that it is a C961 problem. I didn't have error code 8 but I had an intermittent run problem with the bottom quarter of the C961 reading blank. A new 961 solved it.

Who did you buy from and where are you? Also could you share the serial numbers from the motor and controller sides? It may help others and current users to have an idea when the problem units were built.

Thanks and good luck!

Tom

The factory responded and confirmed the error code 8 is a problem with an internal hall sensor. They sent a video showing a technician disassembling the unit, disconnecting all internal connectors between the controller and motor, and then reassembling. They also wanted me to reseat all connectors in the entire system. Pretty straightforward stuff. I have an extra C961, so I can try that as well. I'll report what I find out.

Thanks for the input.

Mark

[jslabonte]

It would be very nice of you to upload the video somewhere if you can!

[rpgear]

Another possible cause of the turn on and then blank screen could be a poor battery connection. Check the wires and connections to the battery to confirm you are getting a solid connection with proper voltage between 42V-60V.

Once I start pedalling the bike, the display comes back on, but there is still no power being applied through PAS or the throttle. The display continues to act like there is nothing wrong, with the exception that the er 8 comes up in a blank screen at start up. The voltage is reading about 54V at the battery taps as well as at the connectors going into the motor. I did read somewhere that any error codes must be cleared or the system will not function.

Pouring down rain here in sunny Florida, so will have to wait until Sunday to dig into the motor assembly.

Mark

[joshseitz]

The voltage is reading about 54V at the battery taps

Can the 36V BBS01 handle that high voltage? I would imagine that would exceed the upper voltage cutoff of the BBS01 controller.

[teslanv]

Yep. Good catch, Tom. The BBS01 probably has a much lower HVC. Try running it on 42V. Max.

[rpgear]

Yep. Good catch, Tom. The BBS01 probably has a much lower HVC. Try running it on 42V. Max.

Yeah, you're right - that is too high! Strange, as it's a "test battery" consisting of three new 12V 5AH SLA's running in series. I just put it together. I'll take the pack apart tomorrow and test the individual batteries, but they should be running about 13-14 volts each. That would be great if that's it!

Mark

[tahustvedt]

I would be surprised if the BBS01 controller couldn't handle the same voltage as the 48v BBS02. LVC will be very low at 32 V though.

I guess I'm surprised.

[rpgear]

Yep. Good catch, Tom. The BBS01 probably has a much lower HVC. Try running it on 42V. Max.

Overnight I started questioning the accuracy of my 20 year old Craftsman multimeter. This am, I pulled out one of those freebie Harbor Freight multimeters. Sure enough, the Craftsman apparently went haywire. Test of each battery came in at 12.8V and the total pack was at 38.4V, so the battery does not appear to be the culprit. The C961 is still showing er 8, so I'll go into the drive next to check the connections.

Mark

[rpgear]

Figured it out. The internal hall sensor connector was loose. It looks like the connector was not completely seated when the silicone was applied to lock in the connector.

You can see in this image that the connector has just popped up slightly, probably disabling one or more of the hall sensors.

In this image, you can see the silicone had seeped into the seat where the rubber base of the connector would sit. I could push the connector into place, let go, and it would pop right back out. This had to be cleaned out with an Exacto scraper. Once that was done, the connector seated properly, and the motor came to life.

This shows the connector in place, and sealed back in permanently.

Bike works great. This was just a minor assembly glitch, but shows the importance of bench testing during final inspection. I think this probably pertains to dealers as well.

Thanks for your input.

Mark

[tomjasz]

Great, thanks for the photos, more for the knowledge base!

Tom

[untilsummer]

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