Bafang bbs01b question

[Jdyog]

Hi everyone,

Long time reader, first time poster with a question about the 250w Bafang BBS01b that I’m wondering if anyone can help me with.

I’ve converted a front-loading cargo bike with the Bafang BBS01b. I did this last year, reprogrammed it following this guide -https://edrivenet.com/bafang-programming/ - and have been enjoying it ever since. I’m not looking to make it go super fast or anything - the speed is still capped at 25kmph. I just reprogrammed it to make the assistance a little bit smoother.

I’ve recently moved city and where I am now is much more hilly. The bike is really struggling on the hills. I live about 100m up a really steep hill, which leads out of town, so people drive pretty fast up it. It’s not a great situation when I’m in max assist, lower gear, and struggling to hit 10kmph.

So, I had another look at the programming and read that because I have a bbs01b, I could change the current limit from 15 to 18. I did this, took it out for a spin, and brilliant - it was drawing about 640w of power up the hill and holding a speed of about 16kmph; an improvement. However, when I took it out again, I was coming back up the hill, peddling and also throttling for max assistance, and after about 20 seconds of this, the motor cut out. The display then showed the exclamation mark inside the brackets. I had always thought this meant the brakes were on. After this, I couldn’t get any assistance from the motor.

Unplugging the screen and re-plugging it back in seems to fix the problem. Have I caused some kind of damage to the screen? Is the motor cutting out because I’m asking too much of it? Should I just put the current limit back down to 15 and suck it up on these hills? Initially when I reprogrammed it, I accidentally plugged the reprogramming cable into one of the brakes; could that have caused an issue? Might it be a problem related to the brakes that’s unrelated to the reprogramming I’ve done? I’ve checked the brake cable connections and none of them are loose.

I hope that’s enough info to go on and thanks to anyone who can shed some light on this!

J

 

[cyclebuddy]

...I was coming back up the hill, peddling and also throttling for max assistance, and after about 20 seconds of this, the motor cut out. The display then showed the exclamation mark inside the brackets.

Others will likely know better than me, but I always understood that to mean the motor has overheated. It should reset and work again once it's cooled down.

 

[guerney]

Unplugging the screen and re-plugging it back in seems to fix the problem. Have I caused some kind of damage to the screen? Is the motor cutting out because I’m asking too much of it? Should I just put the current limit back down to 15 and suck it up on these hills? Initially when I reprogrammed it, I accidentally plugged the reprogramming cable into one of the brakes; could that have caused an issue? Might it be a problem related to the brakes that’s unrelated to the reprogramming I’ve done? I’ve checked the brake cable connections and none of them are loose.

The brake connectors only have 3 pins, the display/programming connector has 5... perhaps check your brake cable's pins?

 

[egroover]

Once you have it fixed try 'keep current' at 100% (under the peddle assist tab) in the programming. This keeps full power when you change to a lower gear (and your cadence increases), exactly what you want and need for climbing hills
I run mine at 15a which peaks at just over 500w which I find is more than enough for most hills...try the above keep current setting and 15a and see how it goes before increasing back to 18a (if its overheating in winter it'll be more of a problem in summer)

 

[Jdyog]

Others will likely know better than me, but I always understood that to mean the motor has overheated. It should reset and work again once it's cooled down.

Thanks - I thought this might be the case. I’m going to try some other settings and see if that works!

 

[Jdyog]

The brake connectors only have 3 pins, the display/programming connector has 5... perhaps check your brake cable's pins?

Good point - I don’t even know how I did it, to be honest. I’ll check to see if I’ve damaged them.

 

[Jdyog]

Once you have it fixed try 'keep current' at 100% (under the peddle assist tab) in the programming. This keeps full power when you change to a lower gear (and your cadence increases), exactly what you want and need for climbing hills
I run mine at 15a which peaks at just over 500w which I find is more than enough for most hills...try the above keep current setting and 15a and see how it goes before increasing back to 18a (if its overheating in winter it'll be more of a problem in summer)

Thanks - I’m going to give this a go. I had been using the throttle as an override on the hills, and even with that it was struggling, but maybe upping the keep current for the PAS will help!