BBS01b programming problems

[bobbyo]

Hi,

I recently did a DIY Bafang BBS01b build with a 48V 250W motor from this AliExpress seller. I bought the USB programming cable to reprogram the settings but I was confused to find that the Max Current for my controller is 12A (see picture) which seems pretty low and is not the 15A advertised on the AliExpress product page.

Have I been given a rubbish controller? Is there something I need to do to unlock the controller current limit like update the firmware?

Many thanks

 

[peter.c]

Thats fixed in the firmware at 12 amps the 15/17 amp is the 500w version
Suspect that is a custom version to meet the 250watt limit

 

[Nealh]

That is still 576w output so about right for a 250w rated motor. If wanting a 250w rated motor one can't have his cake and eat it.
The 15a rating you speak of will be for the 36v 250w model which is 540w output.

 

[bobbyo]

Thanks for taking the time to reply guys.

I am pretty happy with the motor as is, as I am trying to make a legal build. I was just interested in playing around with the settings and seeing what it was capable of and tweaking the settings to make the PAS feel a bit more natural. Do you have a favourite configuration for the Basic + PAS settings for these motors?

I am quite ignorant as to how motors work - how is the "true" output (576w) related to the rated 250w of the motor? Would it be possible to change firmware to allow a higher current?

I assume the 576w comes from 48V x 12A is that correct?

Cheers

 

[Nealh]

Thanks for taking the time to reply guys.

I assume the 576w comes from 48V x 12A is that correct?

Cheers

Yes.

The 576 is max power via throttle or highest PAS level, one will need to have a highish cadence for max power.
Unfortunately my experience with BBS01 is pre the 01b models and I have had two controllers blow so I have little faith in it's longevity and reliability.

I shall be looking at getting a tsdz which will suit my 60 - 70 rpm cadence better.

 

[sjpt]

I am quite ignorant as to how motors work - how is the "true" output (576w) related to the rated 250w of the motor?

The 576w is peak output from the battery and controller, input to the motor. So the 'true' peak output will probably be around 80% of that, 460w. You'll only get that peak if all the parameters such as cadence etc are correct; the motor input will never go above 576w, and if cadence etc are wrong the efficiency will drop. If you ran at that peak for any length of time you might harm the controller or motor.

The 250w is very much a nominal rated output value that the motor should be able to maintain indefinitely without damage. Often the same motor will be rated separately in the US (eg 350w) and the rest of the world (eg 250w), not because of technical differences but because of legal ones.

 

[bobbyo]

Thanks again for the advice guys.

Does anybody know if it is possible to program the throttle to make it legal (I may well be wrong but I believe this means it should be limited to 4mph when the pedals are not turning and 15.5mph when they are) and what settings to use to achieve this? I've set the speed limit in my display but I think my throttle seems to override this and go faster.

Thanks again

 

[peter.c]

The throttle page in the software allows the option to adapt the settings to a max speed or to a power level. the default option is often set as { by display} which = the max speed setting not seen the option of 4/15.5 mph

 

[guerney]

There's no way to program my BBS01b to limit the throttle to 6km/h when the pedals are not moving, and for the firmware to automatically increase the throttle speed limit to 25km/h only when they are. Which is why my next conversion may be a KT.

 

[bobbyo]

Thanks again guys, looks like I may need to remove my throttle then