BBS02B Install Need Help PAS not working right

ace5000

New Member
Region
USA
Hello I hope this is the right forum. Please advise if not.
New install: 750W, 48V
Trek 700C, 46T CG, 11-32 8 speed in rear.
Speed and shift sensor installed, 500C Display
Casual riding

The install was just completed. The Throttle seems to works fine except it is either full speed or nothing. But, the PAS only works when peddling very fast. Then the motor kicks in like crazy when I don't need it. All connections were checked.
I flashed Karls special sauce, but still NO PAS when pedaling normally.

If this is defective, I have time to send it back.

Any ideas???
Thank you
 
Last edited:

Gionnirocket

Well-Known Member
Region
USA
City
Y. O.
Hello I hope this is the right forum. Please advise if not.
New install: 750W, 48V
Trek 700C, 46T CG, 11-32 8 speed in rear.
Speed and shift sensor installed, 500C Display

The install was just completed. The Throttle seems to works fine except it is either full speed or nothing. But, the PAS only works when peddling very fast. Then the motor kicks in like crazy when I don't need it. All connections were checked.
I flashed Karls special sauce, but still NO PAS when pedaling normally.

If this is defective, I have time to send it back.

Any ideas???
Thank you
Perhaps your .el files have an error in them.
I posted a few pics of my updates here... But there is also a side by side comparison with what came stock on my BBS02B. I would try to load the stock Bafang settings and see if that works.
Also.... Try disconnecting the shift sensor. Not that it sounds to be the issue.. But it is not necessary to have a working system so at least you can eliminate it as a test without issue.
 

m@Robertson

Well-Known Member
Region
USA
Try these settings. Not because they are better so much but because they are *different*. See what happens if anything.


I am about to back them off still further once I finish a test later today. These settings (pictures below) are based on what is in the article. They will start up the bike more slowly and allow finer throttle input at the lowest level than what you see in the article. I am also dropping the Keep Current to 30% on the Pedal Assist screen. I've been using these milder settings on my Surly Big Fat Dummy for some time and just ported them over to a second bike. I was testing yesterday and found these settings vs. the ones in the article allow for much lower initial throttle tip-in. About 50w and 0.5-1a vs. 100w and about 1.5-2. Either setting should stop pedal assist/motor engagement from even starting until you cross 5 mph.

EDIT: These screens use BB-Sensor-32 for pedal sensor type. Usually you see DoubleSignal 24. I tend to leave this setting at whatever the motor was originally programmed to run on. this motor came from the seller (Luna) with that setting. I have switched back and forth between BBS32 and DS24 and have never seen a difference in behavior, so I revert to what it came with. The older motor in the linked article uses DS24. I would only play with this setting as a last resort if you can't figure out a solution. Also ignore the 30a current limit :)

PXL_20210502_161915192.jpg
PXL_20210502_161923786.jpg
PXL_20210502_161932563.jpg
 
Last edited:

Gionnirocket

Well-Known Member
Region
USA
City
Y. O.
Hello I hope this is the right forum. Please advise if not.
New install: 750W, 48V
Trek 700C, 46T CG, 11-32 8 speed in rear.
Speed and shift sensor installed, 500C Display
Casual riding

The install was just completed. The Throttle seems to works fine except it is either full speed or nothing. But, the PAS only works when peddling very fast. Then the motor kicks in like crazy when I don't need it. All connections were checked.
I flashed Karls special sauce, but still NO PAS when pedaling normally.

If this is defective, I have time to send it back.

Any ideas???
Thank you
One other thought... Make sure you have your battery V set correctly in the display settings.

500c-setup_orig.jpg
500c-operation_orig.jpg
 

ace5000

New Member
Region
USA
Gionni - I think that was it. I have not tested it outside yet, but the motor kicks in now with pedal movement. It was set to 36v when I have a 48!
Thank you very kindly!
 

Gionnirocket

Well-Known Member
Region
USA
City
Y. O.
Gionni - I think that was it. I have not tested it outside yet, but the motor kicks in now with pedal movement. It was set to 36v when I have a 48!
Thank you very kindly!

Even a broken clock is right twice a day. 🙃
Glad I could help, enjoy!

On settings.. Don't get stuck in thinking that someone else's settings will be perfect for you. They are good for getting you close and helping you understand how they work... But in the end there are so many variables ( bike, gearing, weight, needs, amount of physical effort you're capable of and how much exercise you want are just a few) and they can be very personal.