Which external controller for BBS01?

I would like to experiment with an external controller on my BBS01. There are a few features of the standard BBS0X controller that can't be changed in software and I am hoping these will be eliminated by going external.
Also I can then run CA for power controlling.

What I am looking for is a 6-FET 36V sine-wave controller that will run the BBS01 unit.
I would like it to be programmable for current settings and a few things like that. Are all these cheap controllers programmable?
Needs to have throttle (also can run without it)
Needs to have PAS (also can run without it)
Sensor mode (maybe even one of the learning ones - Jasoncontroller?)
If possible it should be off something like ebay as the freight is cheaper to Australia.

What would be the recommendation for a controller? Looks like alot of clones / copies out there and not sure if they are programmable. Just need pointing in the right direction before wasting money on some dodgy one.

Thanks

SB

Might be worth reading about using a Ca v3 with the Bafang controller before endeavoring to use an external controller. It's effectively designed to control a controller to a certain extent including pas. Kepler modified his Bafang loom to use a Ca V3 on here and went from there. I don't really see the additional benefit for what you will spend on another controller.

Read that thread and Kepler even ran into some limitations using the Bafang controller. These limitations are the ones I am trying to avoid by going external.
The stock controller limits to power to low in the cadence range for me. There is no setting in software to increase this. I have maxed all the speed settings out so the motor speed limit must be hard coded.

Spaceball said:

Read that thread and Kepler even ran into some limitations using the Bafang controller. These limitations are the ones I am trying to avoid by going external.
The stock controller limits to power to low in the cadence range for me. There is no setting in software to increase this. I have maxed all the speed settings out so the motor speed limit must be hard coded.

Click to expand...

Have you tried setting the 'Keep Current' to 100%?

Both the "speed limit" and "keep current" are at 100%.
I believe that I am at the speed limit that the software is set for hence the reason to try an external controller. They might help a little then I might have to up the voltage. That will be the last resort due to the expensive 36V battery I already have.

hmm ok. that's an interesting discovery in itself really, it means Bafang have coded the limitation into their software without offering the way to change it. Interesting.

I haven't seen anyone use BBSx with external controller particularly not with BBS01. After taking one of these apart, I don't think I would want the motor RPM beyond what it has been designed for, I suspect it won't last long.

But you'll probably do it anyway right? :lol: I think you will find the pedelec forums more experienced with modifying BBS01 as the power of it's a bit low for this forum.

Thanks for the heads up on the other forum. Most on here want more power where I am after more crank RPM at low low power levels to meet the 200W Oz limit.
In terms motor RPM I am looking at crank RPM of around 100, max. So not a huge speed increase. I haven't seen a power curve for these motors so I am not sure where this RPM will fall.

I understand what you want - you want it to keep adding power at the cadence you want to pedal, which is above the pedal cadence which Bafang has set the power cut to be both in stock form and after manipulating the programming software.

The problem is what RPM the motor is doing. The adjustments you have already made are based on motor RPM, not pedal cadence RPM (although this is what you want to change).

I'm concerned that in order to add power, the motor is spinning at a speed that is relational to your pedal cadence and Bafang appear to have cut it off below what you want it to operate at. What I'm saying, is I don't know whether it will damage internally if you force it above the motor speed it is designed for. I really don't know and you will be the pioneer of it, as far as I am aware. Its just something to keep in mind.

Totally agree. That is why I am looking for a cheap controller for the testing.
I believe that the motor should handle a few more RPM. It still pulls strong at the current max RPM and doesn't feel like it has fallen off the efficiency curve.
My normal ride home is 20Km and I am pulling 230 battery watts. When I get home the motor is slightly above ambient.
If i was adding timing to get more RPM then I would be worried. Seen many RC motors go up in smoke from just a little too much timing.

I wouldn't state it as fact, but i'm quite sure the bbs controllers do not limit motor rpm. The lower power bbs motors are slower, higher power versions spin faster. Some complain the 36v 250w are too slow for them. I've not heard that complaint for the high power models. Each different model of bbs kit, has a different number of turns on the motor core, as required to match supply voltage and the required rated power.
IMO a faster wound motor core with standard controller would do what you need. Maybe going with a 36v 350w motor core, instead of the 250w motor core, for example. You can't make a motor turn faster than the windings and supply voltage dictate, unless you use timing advance, it's simpler (in this application) to just use a faster wound motor IMO.

Thanks Cell_man.
Is there any documentation on motor speed @ rated voltage for the BBS series on motors?
I also feel that the power tapers too quickly not to be affected by the controller.
Know any good controller where I can add a few extra degrees of timing at the higher RPM? Re-wind the stator?
Hmmm. Looks like I bought/ was sold the wrong motor. Might just have to go hub motor.

What motor are you running, a 250w bbs01? The infineon controllers have a sort of phase advance by programming to more than 100% speed, but It's not very precise, not all motors run well and it's hard on the controller. I've heard the bbs motors are more noisy when run on a non sine wave controller. The standard controllers are a sine wave type, to some extent at least.

I'll try to test some no load figures for the various versions, but i don't have the figures to hand.

BBS01 - 250W is the one that I have.

I will do some testing on the weekend checking if there any difference in crank RPM between a fully charged battery and 1/2 full.

Did some more testing on the weekend and can confirm that the crank speed of the BBS01 is limited by battery voltage.
The battery was around 30% capacity so I could do some upper and lower battery voltage testing.
So the results are. These are approximate battery voltages measured by an external GT POWER watt meter. Crank RPM (cadence) was measured using a Garmin Edge 500 with crank mounted cadence sensor.
Controller set for 6A max current.
Bike was mounted in resistance trainer.
No Load speed is the maximum RPM that was obtained with no load on the back wheel with throttle only.
Full load was the RPM that the power started to reduce as the crank RPM was increased past the throttle only loaded speed.

Fully charged battery.
No load (~25W), 41V - 99RPM
Full Load (245W), 41V - 93RPM

Low battery.
No load (~25W), 37V - 85RPM
Full Load (200W), 36V - 81RPM

It can be clearly see the crank RPM drop off with respect to voltage. A quick calculation shows that the unit including reduction gears has K of 2.3 (RPM per Volt).
Would need to through a lot of timing at this motor get the RPM up at the lower voltages which I am not prepared to do.
So it looks like this unit is not for me.
Anyone want to buy a lightly used BBS01 unit?