Programming the Bafang Middrive BBS01+BBS02

[opperpanter]

Parameter "Limit current" actually doesn't have anything with current, it simply set throttle voltage.

I think it does have current limiting capabilities otherwise if you just set the throttle voltage without measuring current, you would not have assist right up to the the motors max RPM.

The controller may well adjust current limit through manipulation of the throttle signal however I am sure it also has a current measurement feedback to do this.

All information points to it being current limitation, like most other (speed limited) controllers do I believe.
Otherwise, If you set max current to 20%, that would give you less than 10V?

 

[dusan]

My latest testing give me some results.
I modified Basic tab parameters as below to save battery and increase comfort.
I am still playing with "Work mode" parameter to try simulate torque sensor.

 

[rscamp]

My latest testing give me some results.
I modified Basic tab parameters as below to save battery and increase comfort.
I am still playing with "Work mode" parameter to try simulate torque sensor.

I ended up with quite similar current values - a bit of a log progression gives finer adjustment at lower assist levels.

 

[dusan]

I did another testing with different values of "Work mode" parameter and I didn't find any influence. I guess this parameter comes from hub motor where you could define relation between crank and wheel angular speed. Values seem to be in Hz x 10. Probably best to keep 0.
There seems to be no possibility to simulate torque sensor. Anyway with my actual Basic parameters modification I can safely achieve 5Wh/km consumption.

 

[DaDo.Bzz]

Maping PASS 0-5 to PASS on basic tab

Finally found strange mapping for 0-5 (change in advanced setup menu on LCD)

PASS 0 -> 0
PASS 1 -> 2
PASS 2 -> 3 to 4? (Not sure ,did not searched for this one)
PASS 3 -> 5 to 7? (Not sure ,did not searched for this one)
PASS 4 -> 8
PASS 5 -> 9

Dont get it, in manual of lcd 965 is written something different.

 

[rscamp]

Hold the phone.

I discovered something today that significantly changes how I can use the BBS0X system. If it is documented here on the 'Sphere somewhere I guess I missed the memo.

The assist level speed percentage limits the top speed with pedelec. For example, setting maximum speed in the menu to 50km/h and setting speed percentage to 64% nets a legal 32km/h maximum assist speed in pedelec mode. But this speed percentage value actually limits BOTH the cadence and the top speed at the same time. So the power level also diminishes at a certain cadence.

Presumably, the cadence limit is a percentage of maximum cadence. I haven't confirmed this yet. If so, playing around with maximum speed and percentages will result in different cadence limits at which power assist diminishes for a given assist level speed percentage. An interesting effect of this is that a gear ratio change which results in a lower cadence brings back the assist. Eventually the power level is diminished entirely by attaining the maximum set speed.

It soon became apparent this could actually be used to aid with shifting. For example, after accelerating to the cadence limit, there is no longer any assist power on the chain so a smooth shift can be made without applying any brake or other throttle cutoff. Then after achieving the cadence again the power drops off again and another shift can be made - and so on until the maximum speed setting is reached. This approach works quite well in most situations and I'm surprised I haven't seen anything written about this anywhere.

With this method, less time is lost without power and close-ratio shifts are a bit faster and certainly easier. If the display shows power (C965) then shifts can occur as the value approaches zero. It is also possible to go by feel. This doesn't work so well if climbing a steep hill and the rider power input is too small to get the assist level close to zero.

Anywho, this was a pleasant surprise! And one of the coolest things about this is throttle override provides full speed - like when you witness a robbery and need to catch the bad guys.

The settings I have been experimenting with are shown below. Maximum speed is set to 50km/h in the menu. The 64% assist level speed limit nets about 32km/h maximum speed in pedelec and the 50% assist level speed limit nets about 26km/h maximum speed in pedelec.

 

[DaDo.Bzz]

Hold the phone.

I discovered something today that significantly changes how I can use the BBS0X system. If it is documented here on the 'Sphere somewhere I guess I missed the memo.

The assist level speed percentage limits the top speed with pedelec. For example, setting maximum speed in the menu to 50km/h and setting speed percentage to 64% nets a legal 32km/h maximum assist speed in pedelec mode. But this speed percentage value actually limits BOTH the cadence and the top speed at the same time. So the power level also diminishes at a certain cadence.

Presumably, the cadence limit is a percentage of maximum cadence. I haven't confirmed this yet. If so, playing around with maximum speed and percentages will result in different cadence limits at which power assist diminishes for a given assist level speed percentage. An interesting effect of this is that a gear ratio change which results in a lower cadence brings back the assist. Eventually the power level is diminished entirely by attaining the maximum set speed.

It soon became apparent this could actually be used to aid with shifting. For example, after accelerating to the cadence limit, there is no longer any assist power on the chain so a smooth shift can be made without applying any brake or other throttle cutoff. Then after achieving the cadence again the power drops off again and another shift can be made - and so on until the maximum speed setting is reached. This approach works quite well in most situations and I'm surprised I haven't seen anything written about this anywhere.

With this method, less time is lost without power and close-ratio shifts are a bit faster and certainly easier. If the display shows power (C965) then shifts can occur as the value approaches zero. It is also possible to go by feel. This doesn't work so well if climbing a steep hill and the rider power input is too small to get the assist level close to zero.

Anywho, this was a pleasant surprise! And one of the coolest things about this is throttle override provides full speed - like when you witness a robbery and need to catch the bad guys.

The settings I have been experimenting with are shown below. Maximum speed is set to 50km/h in the menu. The 64% assist level speed limit nets about 32km/h maximum speed in pedelec and the 50% assist level speed limit nets about 26km/h maximum speed in pedelec.

Hello

limit speed parameter limit just cadence (max is 110 or so, I have my normall peddaling setup to 62%). Bafang is programmed to lower power as you reaching setup caddence up to 0W (depends on keep curent when) - this is very good function to save batt energy. Speed is taken from rear speed sensor, if you just reach speed setup on display, motor will stop to giving you power. That simple, but took me quite a lot time to figure it out. ))

 

[DaDo.Bzz]

Moreover, when you have setup low power air drag will limit your max speed (for 200W it should be about 22kmh) doesnt matter what gear you have (if you dont have too low speed limit)

 

[cycborg]

The assist level speed percentage limits the top speed with pedelec. For example, setting maximum speed in the menu to 50km/h and setting speed percentage to 64% nets a legal 32km/h maximum assist speed in pedelec mode. But this speed percentage value actually limits BOTH the cadence and the top speed at the same time. So the power level also diminishes at a certain cadence.

The cadence aspect of this is familiar - here's some hard data from Ken Taylor, although others had provided less quantitative observations on this some time earlier. My recollection is that the cadence percentage is referenced to 80 RPM for the BBS01 and 120 RPM for BBS02.

There's less consensus on the speed limit effect, but I'd say that both of your observations are consistent with what I experienced with my controller as originally programmed. When accelerating, the power would taper off at a certain cadence, I'd upshift, the power would resume until the cadence was again reached, etc., until a speed limit was reached even though I still had a couple gears left to shift to. I now have it programmed so that the Limit Spd is 100% at all levels so that changing the level simply changes the current (and therefore power). I only experience the power cut at the hard limit of 50 kph.

It soon became apparent this could actually be used to aid with shifting. For example, after accelerating to the cadence limit, there is no longer any assist power on the chain so a smooth shift can be made without applying any brake or other throttle cutoff. Then after achieving the cadence again the power drops off again and another shift can be made - and so on until the maximum speed setting is reached. This approach works quite well in most situations and I'm surprised I haven't seen anything written about this anywhere.

I think the main reason people have removed the speed/cadence limits is that, while what you describe is nice when accelerating, when you get to an uphill, the effect is the opposite - as cadence decreases, power ramps up just when you want the power to drop so you can downshift. So you still have to do the brake tap or throttle tap or whatever technique you use for power interruption. Or plan ahead and downshift while you're still at full cadence.

The other thing is, why should speed and cadence limits be linked? I suspect this is a holdover from hubmotor programming that was awkwardly ported to this system. I like my cadence to be in a pretty narrow range, and even if I wanted to limit my speed for safety or legal reasons, I'd still want to pedal at the same cadence.

All that said, if these settings work for you, awesome. That's the great thing about being able to tweak all these parameters - we all have different preferences and we're able to find unique settings that optimize the system (more or less) to the style we like.

 

[rscamp]

The cadence aspect of this is familiar - here's some hard data from Ken Taylor, although others had provided less quantitative observations on this some time earlier. My recollection is that the cadence percentage is referenced to 80 RPM for the BBS01 and 120 RPM for BBS02.

Subjectively, based on my limited ability to judge cadence, I think this is correct.

There's less consensus on the speed limit effect, but I'd say that both of your observations are consistent with what I experienced with my controller as originally programmed. When accelerating, the power would taper off at a certain cadence, I'd upshift, the power would resume until the cadence was again reached, etc., until a speed limit was reached even though I still had a couple gears left to shift to. I now have it programmed so that the Limit Spd is 100% at all levels so that changing the level simply changes the current (and therefore power). I only experience the power cut at the hard limit of 50 kph.

There is absolutely a speed limit affect relative to the maximum speed set in the menu on my system. And it is predictable based on the simple math involved. In my case, this dual effect of the assist speed limit on cadence and set speed limit remained undiscovered until settings were made that would uncover them. But yes, I too thought there was no benefit to setting a speed limit on assist levels. It turns out there is one if you are inclined to use it as a shift aid or to limit speed on a ride for some reason.

I think the main reason people have removed the speed/cadence limits is that, while what you describe is nice when accelerating, when you get to an uphill, the effect is the opposite - as cadence decreases, power ramps up just when you want the power to drop so you can downshift. So you still have to do the brake tap or throttle tap or whatever technique you use for power interruption. Or plan ahead and downshift while you're still at full cadence.

Yes exactly. The rider needs to do different things to shift depending on whether or not the cadence limit can be reached.

The other thing is, why should speed and cadence limits be linked? I suspect this is a holdover from hubmotor programming that was awkwardly ported to this system. I like my cadence to be in a pretty narrow range, and even if I wanted to limit my speed for safety or legal reasons, I'd still want to pedal at the same cadence.

Dunno. But it does open the door to this other way of backing off power for shifting.

All that said, if these settings work for you, awesome. That's the great thing about being able to tweak all these parameters - we all have different preferences and we're able to find unique settings that optimize the system (more or less) to the style we like.

Yup!

 

[dusan]

Hello,
Where can I download controller firmware?
Thanks

 

[cycborg]

Hello,
Where can I download controller firmware?
Thanks

http://endless-sphere.com/forums/viewtopic.php?f=28&t=58780&p=884000&hilit=controllerst#p884000

 

[dusan]

I changed configuration setup again to better follow my cadence on various XC terrain. Work mode parameter helps me keep power at same or higher level when accelerating, actual controller logic handles cases when cadence is same but speed decreased, uphill case. Also changed SlowStart mode and Start current to behave more dynamically. I decreased max current and usually using PAS level 3 that varies from 25W to 100W based on terrain and cadence.
Actually with new settings I don't need to change PAS level at all only in case of strong uphill. I am switching only rear gears. I also didn't install throttle.
My actual firmware version is 1.0.0.1, I am wondering if firmware update, to v4, wouldn't help run motor smoother with more precise current control as v4 is developed for 9 Fets controller.

 

[tomjasz]

v4? Are you referring to the mythical fourth version of the BBS02 controller? I think that's a creation based on speculation not on any hard facts or data. Certainly nothing from Bafang and nothing that resellers are acknowledging either. The last discussion I had with someone regarding the versions was disappointing. That person remained clueless about the BBS0x serial and it's date code. Without which any allusion to versions is useless.

 

[dusan]

I was referring to mwkeefer post but maybe firmware update require controller update also. http://endless-sphere.com/forums/viewtopic.php?f=28&t=50104&p=1027197&hilit=Mwkeefer#p1024247

 

[bgt]

Just received a new BBS02-500W/36V and what i see in the flash chips data is:
Mft: HZXT
Model: SZZ9
HW: v1.1
FW: v1.0.0.1
stamped data: 1503041533 on controller and 140904303 on mechanical part.

My first BBS01-250W/36V motors bought in august 2014 had:
HZXT
SZZ6
v2.2
v2.0.1.1

Why is the model number so different on the new 1? Ok, just see this is the BBS02 model.
I thought the FW should be in the 4 series now? Just see Tom saying there is no 4th firmware.

 

[opperpanter]

They started over with the numbers for the SZZ9 model I read somewhere.

 

[DaDo.Bzz]

Just received a new BBS02-500W/36V and what i see in the flash chips data is:
Mft: HZXT
Model: SZZ9
HW: v1.1
FW: v1.0.0.1
stamped data: 1503041533 on controller and 140904303 on mechanical part.

My first BBS01-250W/36V motors bought in august 2014 had:
HZXT
SZZ6
v2.2
v2.0.1.1

Why is the model number so different on the new 1? Ok, just see this is the BBS02 model.
I thought the FW should be in the 4 series now? Just see Tom saying there is no 4th firmware.

It has 9 FET. v1.0.0.1 is ok, latest one for this new controller.

 

[tomjasz]

I don't know how versions can be extrapolated without any real data and build dates.

 

[bgt]

Just swapped the motor of my bike, the 250W BBS01, for a new 500W BBS02 and made a tour/drive over the cycling paths through the dunes from Scheveningen to Noordwijk and it was a really fast ride. The torque on the 500W is just awsome. It climbs hills like mad going nearly 40km/h up. You saw the racingbike drivers looking a bit amazed that I passed them. Battery consumption is a bit higher on the 500W as is the motor heating up more also. But ofcourse: the more power/speed=the more heat wasted.
My intention was to buy a Bewo kit but I just love torque=BBS0* so thats it. 1 happy biker
https://dl.dropboxusercontent.com/u/11003205/BBS01&02.jpg

 

[tomjasz]

Good news. I'm curious as to how well it will hold up and how it compares to the 350W. I road 6 miles yesterday and it wasn't beyond warm at 18A. I need to read back on confrim what the 36V 350W and 500W have in common. 350W looks to be the same motor size as the 500W. But memory fails me.

Just swapped the motor of my bike, the 250W BBS01, for a new 500W BBS02 and made a tour/drive over the cycling paths through the dunes from Scheveningen to Noordwijk and it was a really fast ride. The torque on the 500W is just awsome. It climbs hills like mad going nearly 40km/h up. You saw the racingbike drivers looking a bit amazed that I passed them. Battery consumption is a bit higher on the 500W as is the motor heating up more also. But ofcourse: the more power/speed=the more heat wasted.
My intention was to buy a Bewo kit but I just love torque=BBS0* so thats it. 1 happy biker
https://dl.dropboxusercontent.com/u/11003205/BBS01&02.jpg

 

[bgt]

Good news. I'm curious as to how well it will hold up and how it compares to the 350W. I road 6 miles yesterday and it wasn't beyond warm at 18A. I need to read back on confrim what the 36V 350W and 500W have in common. 350W looks to be the same motor size as the 500W. But memory fails me.

Just swapped the motor of my bike, the 250W BBS01, for a new 500W BBS02 and made a tour/drive over the cycling paths through the dunes from Scheveningen to Noordwijk and it was a really fast ride. The torque on the 500W is just awsome. It climbs hills like mad going nearly 40km/h up. You saw the racingbike drivers looking a bit amazed that I passed them. Battery consumption is a bit higher on the 500W as is the motor heating up more also. But ofcourse: the more power/speed=the more heat wasted.
My intention was to buy a Bewo kit but I just love torque=BBS0* so thats it. 1 happy biker https://dl.dropboxusercontent.com/u/11003205/BBS01&02.jpg

Tom, I just did 60km this afternoon, not 6 miles

 

[tomjasz]

6miles for this old gimp is nothing by comparison. But it is a good ride for me. Pretty much full throttle with 220lbs and little heat, 2/3 of which was 52Tx11T 24mph. Barely warm. 60km and I couldn't walk for a day or two. Ouch.

 

[bgt]

6miles for this old gimp is nothing by comparison. But it is a good ride for me. Pretty much full throttle with 220lbs and little heat, 2/3 of which was 52Tx11T 24mph. Barely warm. 60km and I couldn't walk for a day or two. Ouch.

I am not a youngster either (66) but its ok. I just like biking and because of doing it I keep fit. If possible I do about 200km a week. I am a pensioner so.....time enough to bike.

 

[tomjasz]

6miles for this old gimp is nothing by comparison. But it is a good ride for me. Pretty much full throttle with 220lbs and little heat, 2/3 of which was 52Tx11T 24mph. Barely warm. 60km and I couldn't walk for a day or two. Ouch.

I am not a youngster either (66) but its ok. I just like biking and because of doing it I keep fit. If possible I do about 200km a week. I am a pensioner so.....time enough to bike.

The BBS01 has made biking possible for me. I was unable to bicycle more than 2k before the eBike. Now I can pedal twice as far under my own power, but the eBike has given me a greatly expanded range. I do not drive a car or operate a motor vehicle. The eBikes were a life changer for me. I do everything I can to help other pensioners rediscover bicycling with PAS.