Ebike Control/Display Settings - Can you help me determine what some of these should be set to?

[thatpondguy]

So my display unit that's being used on a Bafang BBS02b motor with a 52v 20AH battery has these settings:
The bike is a 27.5 on WTB Trail Boss 3.0 tires w/ a 1-10x (now limited to 1-8x) with a 30T Luna chainring.

The display is a "Digitech b-cockpit BL181"
S1 Wheel Size 4.0 – 99 Inch 0.5
(This one was easy, selected 27.5)
S2 Perimeter 0-9999（Calculated by wheel size by default. 3.14*D）
(This one auto-populated based on selection 27.5 wheel size)
S3 Speed Unit 00：Km/h None 00：MPH - -
(I chose MPH)
S4 Speed Limit 00 – 99 （0 means no speed limit） km/h 1
(I chose 0)
S5 # of Magnetics 1-99 / 1
(I have no idea on this one - it's defaulted at 1. What does # of magnetics mean or do?)
S6 Backlight 1 – 5 / 1
(I chose 1, perfectly visible)
S7 Auto Power Off 0 – 99 (0 means always on) min 1
(Left at 10 default)
S8 Protocol - 00：KM5S；-01：Li 2；- 02：Customized
(default of 01 - anything else gives an error)
S9 Voltage 36；48 V -
(So for this I chose 48. It was default at 60 and was working... No option to choose 52. Leave it at 48?)
SA Electricity calculation method - 00：The controller reports the voltage, and display calculates - 01：Controller reported power；- 02：The display detect the voltage and calculates
(This was defaulted at 01, but was showing a newly shipped battery at full power... I changed to 00 and the power is now reading less than half. I'm hoping this is the more accurate choice?)
Sb Walk Mode 00：Yes; 01：No - -
(Chose "Yes" to enable walk mode)
Sc Default Assist 0-max / 1
(Chose "1" to start display in assist level 1)
Sd Max Assist 1-9 / 1
(Chose 9 to have 9 levels of power)
SE** Logo - 00：Digitech（Default）；- 01：Neutral welcome screen；- 02：Customized Logo
(Not really important, left it at 00 default)
SF Reset 00：Yes；01：No
(I believe this resets all settings. Left at 01)
SH Serial communication00：3.3V；01：5V - -
(Display controller was defaulted to 5v, changed it to 3.3v and works fine. Which should it be?)


Any suggestions or recommendations on the red highlighted text would be much appreciated. Thanks all!

 

[PedalUma]

Welcome. You might also want to try the speed limit at 99. Wheel magnets are used to calculate speed. The more you have, up to a point, the more accurate and smooth. Particularly at lower speeds. You can play with the 02 setting after charging the battery. The rest looks fine.

 

[Slaphappygamer]

For S5, try 80. This would be the number of magnets in the motor (16) multiplied by 5:1 gear ratio. I saw a listing for your motor and it had an internal picture and counted the magnets. Also confirmed on another sellers page that listed the number as 16. Typical motor has 5:1 gear ratio, but that is a mid drive motor, so the ratio could be different.

S9, I would set the voltage to 60. A 52v batter will be around 58v when fully charged.

I would also change SA to 02

 

[thatpondguy]

For S5, try 80. This would be the number of magnets in the motor (16) multiplied by 5:1 gear ratio. I saw a listing for your motor and it had an internal picture and counted the magnets. Also confirmed on another sellers page that listed the number as 16. Typical motor has 5:1 gear ratio, but that is a mid drive motor, so the ratio could be different.

S9, I would set the voltage to 60. A 52v batter will be around 58v when fully charged.

I would also change SA to 02

Is there any damage to worry about setting S5 to 80? To be clear, this motor is the latest version (BBS02b) rather than the older no longer produced BBS02. I also have no idea how many gears or what the internal gear ratio is of the motor. We're not talking about the drivetrain gearing right? Like 30T chainring x 10-42T cassette?

the bbs02b is rated at 48v, but the modern motor is very capable at 52v which most people now run on it. Is setting the voltage at 60 forcing it to run higher, or simply giving it a higher limit above 48 for what the battery/controller can deliver?

Thanks!


Edit to add, I think I understand your magnet reference... I think it should be set to 1 because I only have 1 magnet on the spokes which gets sensed by the tires rotation and a speed sensor. I assume it's different on hub motors and that's what you're referring to?

 

[thatpondguy]

You might also want to try the speed limit at 99. Wheel magnets are used to calculate speed. The more you have, up to a point, the more accurate and smooth. Particularly at lower speeds.

Can you explain this a bit more? At 0 (no speed limit) it still appears to calculate speed. By setting a speed limit are you inferring that it will ramp up power differently? I do have a speed sensor/magnet installed on the rear triangle and spokes.

 

[PedalUma]

Let's get @AHicks, and @m@Robertson in this conversation. I have only done only a few Bafang mid-drives and have not used this display. @tomjasz may wish to add to the discussion too. My specialty is with a different mid-drive. With the displays I have used, setting the speed limit to 99 means no limit. They will help with for example setting the Amps so that it is still nice without risking burning up, or over stressing the motor and drivetrain. Yes, the wheel magnet is on a spoke and the pickup on the chain stay. Having nine power levels is good in my opinion because power level 1, with five power levels it a bit to high for me for tooling around town or on a multi-use path with dogs and pedestrians.

 

[Slaphappygamer]

The magnet on the spoke is to measure speed. Without it, your speedometer will not be accurate.

You are correct. When I said “gear ratio” I was meaning the gear ration within the motor. Not the gear ratio of the chainring and cassette. Typically, the motor would have gears inside that would equate to the gear ratio.

 

[thatpondguy]

The magnet on the spoke is to measure speed. Without it, your speedometer will not be accurate.

You are correct. When I said “gear ratio” I was meaning the gear ration within the motor. Not the gear ratio of the chainring and cassette. Typically, the motor would have gears inside that would equate to the gear ratio.

OK, but if it's a single magnet with a receiver, wouldn't it bet set to 1? I'm not understanding the "80" setting. Thanks

 

[Slaphappygamer]

Ahh. Ok. I see. The single magnet belongs to the speed sensor. The magnets that S5 is asking for are in the motor. Your motor has 16 magnets. Usually, this setting wants the motor gear reduction ratio (ex, 5:1) multiplied by the number of motor magnets (16). Gear ration would 5x1=5. Now multiply that by 16. 5x16=80. That’s how I got your number, assuming your gear ratio (of your motor) is 5:1. Other Bafang motors also have a 5:1 gear ratio. That’s why I’m assuming the same gear ratio for your motor.

 

[AHicks]

2 thoughts-
First, though familiar with the Bafang mid drives, not familiar with this display you are using (Digitech).
Second, I've been messing with the KT controllers for a quite while now, so pretty much at home there.

IMHO, if your settings are working, it's pretty fair to assume you're OK. If something is WAY off, THAT'S when you need to start digging for info.

3.3v was likely a good call.....

 

[thatpondguy]

2 thoughts-
First, though familiar with the Bafang mid drives, not familiar with this display you are using (Digitech).
Second, I've been messing with the KT controllers for a quite while now, so pretty much at home there.

IMHO, if your settings are working, it's pretty fair to assume you're OK. If something is WAY off, THAT'S when you need to start digging for info.

3.3v was likely a good call.....

Thanks for that info. Would you recommend changing the "magnetics" from 1 to 80? And the voltage from 48 to 60?

 

[m@Robertson]

I have the same thoughts as @AHicks ... I am very familiar with the Bafang programming, but the display... not at all. With that said:

• S1 - 99 inch wheel size sounds wrong. Usually you calculate the external diameter of the wheel including the tire. So for example your typical 26" wheel with a 4.9" fat tire usually likes a "29 inch" setting.
• S5 - Number of Magnets. I would figure out what the display wants to know. Is it the raw magnet count or what? Getting this wrong can grick the motor so if the motor is working right now change nothing until you learn what you're supposed to do via the display instructions - if as it is with many manuals, the manual instructions appear to be translated from Chinese to English by a Martian, then get to Google and start looking for different versions. Oftentimes you can learn something from different translations as you can with KT manuals (Dilinger did a proper English version of KT settings for example).
• S9 - a 52v battery peaks at 58.8v. Maybe thats less of an error than setting it to 48v? You'll have to play with this and deduce on your own. Frankly any display that graphically gives you a battery guesstimate is garbage. If you can, get a numeric reading of the display ("49.6v" and similar) and learn what the numbers mean.
• SA - See S9 above. Its all guesswork based on your experience learned over time.

This doesn't look particularly useful but here it is anyway:

Company Home

My custom description

www.riding-evolved.com

 

[thatpondguy]

I have the same thoughts as @AHicks ... I am very familiar with the Bafang programming, but the display... not at all. With that said:

• S1 - 99 inch wheel size sounds wrong. Usually you calculate the external diameter of the wheel including the tire. So for example your typical 26" wheel with a 4.9" fat tire usually likes a "29 inch" setting.
• S5 - Number of Magnets. I would figure out what the display wants to know. Is it the raw magnet count or what? Getting this wrong can grick the motor so if the motor is working right now change nothing until you learn what you're supposed to do via the display instructions - if as it is with many manuals, the manual instructions appear to be translated from Chinese to English by a Martian, then get to Google and start looking for different versions. Oftentimes you can learn something from different translations as you can with KT manuals (Dilinger did a proper English version of KT settings for example).
• S9 - a 52v battery peaks at 58.8v. Maybe thats less of an error than setting it to 48v? You'll have to play with this and deduce on your own. Frankly any display that graphically gives you a battery guesstimate is garbage. If you can, get a numeric reading of the display ("49.6v" and similar) and learn what the numbers mean.
• SA - See S9 above. Its all guesswork based on your experience learned over time.

This doesn't look particularly useful but here it is anyway:

Company Home

My custom description

www.riding-evolved.com

S1 - So you would you suggest I change that to 29 on a mountain bike with 27.5 x 3.0" tires?
S5 - I copied that info directly from the manual, that's the extent of detail it gave.
Code: S5 | Value: # of Magnetics | Parameters: 1-99 | Unit: / | 精 度: 1
S9 - Yes, I wish I could see the voltage rather than a sliding bar, but alas: no option.
SA: Yea I agree, I'll play around with this one. Thanks!

 

[thatpondguy]

This is the manual for anyone wondering. See attached.

 

[AHicks]

Have you actually ridden the bike yet? That in itself may answer some of your questions....

 

[thatpondguy]

Have you actually ridden the bike yet? That in itself may answer some of your questions....

Briefly yes, it works fine, but I didn't want to damage it, and I wasn't able to verify speed or give it a good mountain run, especially since we're currently snowed out. I'm here trying to get answers to settings I'm unsure of and optimizing it as best I can. Thanks for the question ....

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[m@Robertson]

S1 - So you would you suggest I change that to 29 on a mountain bike with 27.5 x 3.0" tires?

29 is the common measurement for 26x4.9 fat tires. You need to measure yours and put that number in. Like I said the measurement normally includes the added tire diameter. This assumes your display works like most others do. Actually all others that I have ever worked with but can't guarantee yours is like them. You will determine the relative success of your work with a ride that includes mounting your phone on the handlebars so you can use a speedometer app to verify accuracy. Either that or get someone to drive beside you and call out speed. Another useful bit are those Your Speed Is... signs that local municipalities put up.

 

[thatpondguy]

29 is the common measurement for 26x4.9 fat tires. You need to measure yours and put that number in.

Maybe I missed it, but how do you calculate that? I have 3" width tires, on 27.5 wheels.

 

[m@Robertson]

Maybe I missed it, but how do you calculate that? I have 3" width tires, on 27.5 wheels.

Get a tape measure, and stretch it from one side of the tire to the other, crossing at the axle so you measure the widest point. Start and end point is the top of the tire at each side. That measurement is the overall wheel diameter.

 

[thatpondguy]

Get a tape measure, and stretch it from one side of the tire to the other, crossing at the axle so you measure the widest point. Start and end point is the top of the tire at each side. That measurement is the overall wheel diameter.

3" tire width & 29"from floor to top of tire, going through the middle. I suppose that's my answer? 29" then?