An online business sells 750w BBS equipped bikes that compare in weight and features with mine. The bike alone without the battery weighs 69 lbs. The crank wheel is 44 teeth and the derailleur is a Shimano 9 speed. The battery is 52v,17.5 A while mine is 48v, 21v. The seller says that they programmed the controller to turn it into a 500w street legal bike in Canada and the speed is limited to 32km. They claim a range from 65 to 100km is possible. I wonder what settings they are using to get such impressive results. I limited my controller to 18v as recommended in the guide found on the web and I programmed each of the 9 PAS levels as explained on the web starting at 10 % on PAS 1, etc. Low battery is set at 41. While riding on flat terrain and using only PAS1, I can barely get a 50km range. The display shows around 600w to 760w draw while riding on PAS 1 and middle gear. How could I possibly get the range claimed by that online seller? What settings would make my 750 w behave like a 500w motor?
BBS02 100km range
- Thread starter laudou
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Gionnirocket
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Note my throttle voltage settings are not for a stock Bafang throttle and may throw an error or cause the bike to throttle unexpectedly so I wouldn't change them.
Just do my first two pages
I applied your settings. First major improvement, the motor runs a lot smoother. However, the display still show high watts from 400 to 864 with a very occasional figure below 100w. Besides, even in PAS 1 and first gear with slow pedaling, I quickly get to 31 km/h. How could is slow down the beast to around 15 km/h? In PAS 1 and 2, I mean.
Thanks again
Thanks again
m@Robertson
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600-750w on PAS 1? Holy cow that is quite a lot. On my BBSHD I can show around 50w. No more than 100w. On PAS9 it puts out about 450w. Now, on throttle it can sustain 1750-ish watts thanks to its 52v battery and 30a current limit. But thats throttle.
Whatever it is you are doing, undo it
100 kilometers is about 62 miles in the Imperialist units we use here, and thats do-able on my bike for sure. However I have a 35ah battery ... and its a cargo bike. As was noted earlier on, range estimates carry a LOT of variables including - at some point - a tipping point for battery longevity vs. weight.I can't tell you that, but I can tell you what I do.
Not a lot of science apparent in this speed % progression, but it is the product of a fair bit of trial and error. I picked 100% for PAS9 and reduced it by 7 at each level down until I stopped at PAS1. What this does is, in conjunction with the other settings on the Pedal Assist tab, create motor behavior that is more conducive to dialing back power when I am at high cadence while also at lower assist settings. I usually run at PAS 3 for a normal cruise. If I decide I need more assist the settings give me a steady increase while at the same time providing more and more insulation from the current decay and keep current pullbacks. I'm a lot less likely to want to conserve power if I am pouring on the higher pas settings out of some need to crank them up.
Start current is super gentle because I prefer not to replace chains and cogs. Slow start mode is gentle for the same reason. Current decay is aggressive, and the keep current percentage is unusually low. My thinking is if I can spin the crankarms I am demonstrating by doing so I do not need a lot of assist. So the motor cuts it back. As cadence decreases power comes back in again. All of these settings reduce power consumption and increase range.
Nothing particularly noteworthy here just note the gentle throttle startup percentage, because I like buying parts as infrequently as possible.
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Gionnirocket
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Lower the Speed setting in PAS 1 and 2
Think of the Speed setting as how fast the motor is pedaling
I understand that Speed setting refers to motor speed, not to riding speed, right? Even though I still have that high speed on low PAS levels, I can assure you that your settings are a big improvement over mine. I'll have to wait until tomorrow to run additional tests.
Thanks again
Gionnirocket
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Yes, motor speed.
And try to have some fun and don't make it a job. You'll get there.
m@Robertson
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IIRC the % Speed effect is also affected by the battery voltage of the moment, so trying to get really precise on the analysis there is not fruitful.
Gionnirocket
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Re_reading this... One thing pops out.
The faster you pedal, the less the motor will do
For example if set to maintain a cadence of 50...if you are doing it on your own, the motor will do little to nothing. But if you start to tire out or encounter a hill or wind and your input slows, the motor will assist more.
This said your speed in that PAS if staying in the same gear should remain a somewhat narrow range on flats.
I understand what you are explaining. My hub motor bike does exactly that. When I pedal faster than the selected PAS level, the motor uses no watts as seen on the display. This way I can get a very impressive range out of the 20AH battery and the 500w motor. That's what I would like to get with the BBS3 but that powerful thing seems to insist on assisting me more than I would like, no matter the PAS level selected or the gear I am in.
m@Robertson
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I also see your wheel diameter setting is set at 29", which would correspond to the outer tire diameter on a 26" fat wheel. Its more typical with BBSxx's to use the wheel diameter not including the tire. I know I use tire diameter on my hub motor controllers... Maybe that is throwing things off somehow. It sounds as if you are getting much more assist than is normal for settings that have been shown. Something is getting in the middle here and throwing off the results.
EDIT: Maybe also we are taking something for granted that should not be: If I want to maintain a slower speed while pedaling - typically when sharing a path with pedestrians where a slower speed is desirable for safety - I downshift to a lower gear. If I kept the bike in a higher gear I would be traveling at a much higher speed.
EDIT: Maybe also we are taking something for granted that should not be: If I want to maintain a slower speed while pedaling - typically when sharing a path with pedestrians where a slower speed is desirable for safety - I downshift to a lower gear. If I kept the bike in a higher gear I would be traveling at a much higher speed.
OK. I will set the wheel diameter at 26''. When testing, I only use PAS1 and gear 1 since I want to reproduce the path conditions with pedestrians and all types of slow moving vehicles. But the bike will not let me ride at very low speed; the moment I start pedaling that thing gets going and consumes lots of watts.
m@Robertson
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That just shouldn't be happening. On my BBSHD using the settings I linked above, on PAS1, I can see output as low as 50 watts, blipping up to 100w on occasion. It is effectively so low the display cannot show the real result.
Can you screenshot your *current* settings where this is happening? Assuming the 26" wheel change does not magically cure the problem, which I don't expect it will.
m@Robertson
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Also is there a reason you do not have Speed Limit and Designated Assist Level at 'By Display's Command'? Usually thats how these are set. I'm trying to eliminate variables here.
I will change the wheel diameter setting. But as for taking a screenshot of the meter while riding, it is a challenge for the old man I am. Besides, with the heavy rain currently falling down at the moment, I will have to delay this exercise. I do want to thank everyone here for taking the time to help me solve what is a big problem for me.
m@Robertson
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No sorry I did not mean that. You did a screen shot in Post #18 of your settings. I think that was from the web based Bafang configuration tool. Thats what I meant.
Along the lines of removing variables, I also see that PAS0 has a 100% speed limit reading. Normally that is 0%. Also note how mine are 1 and 1 for the two settings. Supposedly that keeps throttle functional while PAS is set to zero. Given your locale you may not even have a throttle.
I just want to point out that on the 1000w motor I cannot set Designated Assist Level at 'By Display's Command because the DPC18 display I have on that bike only gives two choices: eco and sports. No number of PAS can be selected. But on my BBS3 750w I do have a 850c display that lets me set the number of PAS levels on the display. Could I sort of adapt your settings to my 750 W motor? This way I would not have to replace the display of the 1000W with one that allows setting the number of PAS levels.
m@Robertson
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Just leave the settings alone that you must due to your circumstances. I am just trying to find every possible oddity and eliminate it to find out what it is that is causing this unusual behavior.
For all we know its something in firmware and not accessible to you via the usual settings. For example, one of my BBSHDs was set up from the seller to be a '52v' capable version. That motor has a fixed output limit of 28a, not the usual 30a. And I cannot increase the limit from 28 to 30. Ordinarily I can make changes from 30a on downward but not on that one motor.
Gionnirocket
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I can't read that fast
check your photo. I would try lowering PAS 1 SPEED to 10 and see what happens.
You should be able to shut the motor down pretty easily with pedaling with the settings as is so this is a bit of a mystery.
If you are feeling frogy.... I'd put the 850c display on this bike. Perhaps the display is corrupt.
GIONNROCKET, there is some confusion here. My latest post was a reply to m@Robertson not yours. He gave me his settings for the BBS3 1000w that I wrote on the controller. If my memory is right, you and I were talking about my BBS3 750w which has the 850C display which shows high watts on the 750W.
