surprise results with bbs 'keep current' setting

[minexplorer]

Its the common understanding that the keep current set at 100% will give 100% of the AMPS you have the PAS level set at.Regardless whether you peddle at low or high cadence. If you set the 'keep current ' to say 50% .You will get 100% of the AMPS for the selected PAS when peddling at low cadence and 50% when at high cadence.

When i first built a bbs01 350w (18amp) it was very powerfull on the max PAS.No difference peddling slow or fast. After a controller problem i was sent a new one.it was gutless. I fitted my watt meter and found it would only give 8-8.5 AMPS on max PAS regardless of peddling speed,flat or hilly terrain. I bought a programming cable and found it was set to 40% keep current. Setting to 100% and i had my powerfull bike back again,approx 18.5amps on the watt meter. I assumed the original controller had been set at 100% keep current ,or very close.

Recently after after not using for a while as id built a bbshd,i started using it again.As an economy i set the keep current to 70%. Not so good as it was before. I decided to try an experiment with the throttle as i no longer had the watt meter connectors in place .So with the PAS set to max,i cycled on the flat and hills. Peddling at high cadence i should get 70% of 18amps. Applying the throttle would therefore bring the speed up. It did. Peddling low cadence would make no difference at it would already be at 18amps. Yet the throttle worked the same increasing the speed.

I can only surmise the 'keep current' in fact PERMANENTLY keeps the controller at the percentage of max AMPS you set it at (and of course applies likewise across the whole PAS levels range). So on max PAS My 18 amp bike essentially becomes a 12amp max bike ,when 'keep current' set to 66% or a 9amp max bike when set to 50% etc.

Id be interested to hear if others have found this also.

 

[Fordulike]

Its the common understanding that the keep current set at 100% will give 100% of the AMPS you have the PAS level set at.Regardless whether you peddle at low or high cadence. If you set the 'keep current ' to say 50% .You will get 100% of the AMPS for the selected PAS when peddling at low cadence and 50% when at high cadence.

I think you are correct about the cadence thing, as the PAS sensor is merely an on/off switch, so theoretically the controller doesn't factor in how fast the rider is pedaling.

I reckon the 'Keep Current' operation is based on a time delay. It gives you max amps at start up, then settles down to the 'Keep Current' percentage after a few seconds, as long as the pedals are turning.

 

[minexplorer]

I think you are correct about the cadence thing, as the PAS sensor is merely an on/off switch, so theoretically the controller doesn't factor in how fast the rider is pedaling.

I reckon the 'Keep Current' operation is based on a time delay. It gives you max amps at start up, then settles down to the 'Keep Current' percentage after a few seconds, as long as the pedals are turning.

hi fordulike. You may be right. Though I seem to remember with the new controller that was programmed to 40% ,that it was gutless right from the start offs. when i fitted the watt meter,using max PAS 5, it always hovered around 8 - 8.5 amps,sometimes a brief 9 amps. which would tie in with a controller that has 18.5 amps at 100%.

I have the watt meter wired permanently as a display now ,on another bike ,otherwise id try an check.But i think i remember it well enough.perhaps someone can confirm if their BBS operates more as we are led to understand.

Personally anything less than 100% power available in PAS, is undesirable.So its back to 100% keep current for me an drop the assist level when i dont need it.

 

[minexplorer]

Its the common understanding that the keep current set at 100% will give 100% of the AMPS you have the PAS level set at.Regardless whether you peddle at low or high cadence. If you set the 'keep current ' to say 50% .You will get 100% of the AMPS for the selected PAS when peddling at low cadence and 50% when at high cadence.

When i first built a bbs01 350w (18amp) it was very powerfull on the max PAS.No difference peddling slow or fast. After a controller problem i was sent a new one.it was gutless. I fitted my watt meter and found it would only give 8-8.5 AMPS on max PAS regardless of peddling speed,flat or hilly terrain. I bought a programming cable and found it was set to 40% keep current. Setting to 100% and i had my powerfull bike back again,approx 18.5amps on the watt meter. I assumed the original controller had been set at 100% keep current ,or very close.

Recently after after not using for a while as id built a bbshd,i started using it again.As an economy i set the keep current to 70%. Not so good as it was before. I decided to try an experiment with the throttle as i no longer had the watt meter connectors in place .So with the PAS set to max,i cycled on the flat and hills. Peddling at high cadence i should get 70% of 18amps. Applying the throttle would therefore bring the speed up. It did. Peddling low cadence would make no difference at it would already be at 18amps. Yet the throttle worked the same increasing the speed.

I can only surmise the 'keep current' in fact PERMANENTLY keeps the controller at the percentage of max AMPS you set it at (and of course applies likewise across the whole PAS levels range). So on max PAS My 18 amp bike essentially becomes a 12amp max bike ,when 'keep current' set to 66% or a 9amp max bike when set to 50% etc.

Id be interested to hear if others have found this also.

Bump..Hasnt anyone got an opinion ?, zero interest, im surprised. I remember a time a post like this would have had lots of feedback/discussion. This is an important performance settings for the bbs. Incidently increasing 'keep current' to 100% massively improved the delay/power cut/dead zone, whatever,between PAS/throttle interaction. Which the newer 2017 ? controllers have.

 

[tommie]

I have both the 02 and HD versions and they react differently to similar programming. I have `keep current` set at 80%, i think 100% would eat into your range too much.
No one knows exactly what Bafang are doing with their stock settings and how they interact with each other.

 

[jarob10]

Bump..Hasnt anyone got an opinion ?, zero interest, im surprised. I remember a time a post like this would have had lots of feedback/discussion. This is an important performance settings for the bbs. Incidently increasing 'keep current' to 100% massively improved the delay/power cut/dead zone, whatever,between PAS/throttle interaction. Which the newer 2017 ? controllers have.

“I can only surmise the 'keep current' in fact PERMANENTLY keeps the controller at the percentage of max AMPS you set it at (and of course applies likewise across the whole PAS levels range). So on max PAS My 18 amp bike essentially becomes a 12amp max bike ,when 'keep current' set to 66% or a 9amp max bike when set to 50% etc”

I agree with this statement. I think the existence of keep current allows the throttle to be programmed independent of PAS limitations

Personally I have everything maxed out, but set the maximum current to match battery continuous discharge

 

[wheeliepete]

I think your KT controller setup Jarob10 is an improvement over the BBS, esp. the way the PAS works. I certainly prefer it, feels far more natural.

 

[minexplorer]

I have both the 02 and HD versions and they react differently to similar programming. I have `keep current` set at 80%, i think 100% would eat into your range too much.
No one knows exactly what Bafang are doing with their stock settings and how they interact with each other.

I think your right there.My bbshd was and still is 60% K C and yet suffers no lack of performance from it.I see the amps drop as expected on the dp18 ,when putting effort in and picking up when lightly ghost peddling (tho not down to 60%). The bbs01 performs in a completely different manner as i described. 100% is the only way i feel i can get the control over the performance i want.Dropping to Pas 3 or 4 when i want less power.