S12S / S-LCD3 problem

Golyo

Finding my (electric) wheels
Oct 31, 2015
24
0
41
Budapest
Hello all,
I have a strange problem. When I tested my configuration about a week ago, the throttle worked OK. Now when I am trying to assemble it, it does not.
Parts: S12S controller, S-LCD3 display, Bafang CST motor, 36V battery pack.

I can start the motor, by pressing the down button long, the walking function engages, and the motor spins at about 10 km/h. The throttle is working, the signal is there, the display shows that the motor is working, but it does not. PAS does not work.

It is not low voltage protection, as the display shows that the battery is full.

Any idea is welcome as I've run out of them, and I am getting really frustrated, as I want to try it out after months of waiting.
 

trex

Esteemed Pedelecer
May 15, 2011
7,703
2,669
the pedelec sensor cable is fragile. Check carefully for signs of damage along the cable and especially at the point where the cable goes into the sensor.
If there is a LED on the pedelec sensor, then it should flash when you rotate the cranks. Check the gap between magnet disc and the sensor. The sensor's Hall is sensitive to the position. Post a picture of the pedelec sensor as it is installed if you can.
 

Golyo

Finding my (electric) wheels
Oct 31, 2015
24
0
41
Budapest
By setting back the P4 function to 0, I could use the throttle. I completely forgot that I changed that. The PAS sensor is misaligned with the magnets, I will have to work on that.
Thanks for the help!
After the maiden voyage there is another problem though. It seems the controller cuts out at 39V. I have a huge battery pack (s10p11), so sag should not be big, and although the temperature is pretty low (3°C) it should not be a great issue. How does the controller know what is the nominal voltage of my battery?
 

JuicyBike

Trade Member
Jan 26, 2009
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Derbyshire
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You could adjust setting C12 (see page 32 of the manual). Try setting this to "0", assuming you have a 48V battery.
 

Golyo

Finding my (electric) wheels
Oct 31, 2015
24
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41
Budapest
I have a 36V battery, and now I am charging it. I have a feeling that the controller and or the display thinks that I have a 48V battery. The display is incredibly dim, and it shuts down when I try the throttle while the battery is at 39.1V. Isn't there supposed to be a switch or something for setting your battery's nominal voltage?
 

JuicyBike

Trade Member
Jan 26, 2009
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Derbyshire
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I have a 36V battery, and now I am charging it. I have a feeling that the controller and or the display thinks that I have a 48V battery. The display is incredibly dim, and it shuts down when I try the throttle while the battery is at 39.1V. Isn't there supposed to be a switch or something for setting your battery's nominal voltage?
What setting do you have for C12?
 

trex

Esteemed Pedelecer
May 15, 2011
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post all your P and C settings, something may show up. I am a bit concerned by the dimmed display. It's not a good sign.
 

Golyo

Finding my (electric) wheels
Oct 31, 2015
24
0
41
Budapest
Thanks for the replies! I charged the battery, and now everything seems okay. I have to give it a good go tomorrow. It takes a while to discharge it back to 39V. I restored the default settings for a start.
Also, I had to realise that setting the assistance to 0 also turns off the throttle, it took about an hour to understand what the hell is the problem (thus the defaulting back to factory settings part).

edit: still I find it hard to understand how it showed that the battery is full in the first 30-40 minutes, then started shutting down every time I turned up the throttle. I did not understand what the problem was (still don't but I think I am closer). Then when I returned home, I could check the battery and see that it was at 39.1V, but the display showed it empty. Still would love to understand how the controller and/or the display decides the nominal voltage of the battery.
 
Last edited:

Golyo

Finding my (electric) wheels
Oct 31, 2015
24
0
41
Budapest
Even if you have a speed sensor installed you should know how many pulses your motor generates. If P2 is set to 0 then your speed is absolutely off (it reaches 0 quite fast) when the motor is not working, but it probably uses the speed sensor's data when it is working (because it shows good speed values, unlike when you set your pulse number to a wrong number, like 1 in my case). Chinese logic!
It seems my Bafang CST generates 6 pulses. Yay!

I have a working speed sensor. Hopefully, tomorrow I can use my battery even if the voltage reaches 39 Volts!
 

Golyo

Finding my (electric) wheels
Oct 31, 2015
24
0
41
Budapest
No joy. The same problem persists. Looking at the pretty dim display, it seems it should not be low voltage protection (the battery meter shows a full battery). What other protection can completely turn off the display? I would really appreciate some help here.
Settings:
P1: 80; P2: 6; P3: 1; P4: 0; P5: 00; C1: 07; C2: 0; C3: 8; C4: 0; C5: 08; C6:4; C7-C13: 0; C14: 3
 

JuicyBike

Trade Member
Jan 26, 2009
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Derbyshire
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I'm confused. Are you able to measure battery voltage just after a charge and then again 20 mins later.
You should return C12 to 4, but that shouldn't have much effect. Does your controller clearly show it is 36v?
 

Golyo

Finding my (electric) wheels
Oct 31, 2015
24
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41
Budapest
Hi Juicy,
I want to use it with C12=7 in the long run. The main thing is that changing it to 0 did not change a thing. So probably it is not LV protection. My end voltage today was 39.4V.
Display does not show that it is a 36V battery, but it shows the battery full all the time, that's why I think it is not LVC (however if the controller and the LCD and two different entities it still could be the case).
 

JuicyBike

Trade Member
Jan 26, 2009
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519
Derbyshire
www.juicybike.co.uk
Is that 39.4 immediately after charging, measured using a multimeter at the battery?
Is there anything written on the controller?
 

KirstinS

Esteemed Pedelecer
Apr 5, 2011
3,195
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Brighton
To be honest I seriously doubt this is the issue

But, if the consensus differs then I have a spare LCD (same) to you are welcome to (at cost, not free sorry)
 

Golyo

Finding my (electric) wheels
Oct 31, 2015
24
0
41
Budapest
Is that 39.4 immediately after charging, measured using a multimeter at the battery?
Is there anything written on the controller?
No, no, no. It was 39.4 after I came home. I used it for about an hour total. After charging it was 41.3V. Yes, measured with a good multimeter.

Controller is "S12S torque simulation controller; Model:S12S; Input voltage: DC36/48V; Min.Voltage: DC30/40+-0.5V; Max Current30+-1A; Speed set:1-4.2V; Brake input:Low-level"
s
 

Golyo

Finding my (electric) wheels
Oct 31, 2015
24
0
41
Budapest
To be honest I seriously doubt this is the issue

But, if the consensus differs then I have a spare LCD (same) to you are welcome to (at cost, not free sorry)
A friend of mine just moved to Brighton, so I might take you up on the offer.
 

awol

Esteemed Pedelecer
Sep 4, 2013
1,174
358
Maybe try setting C11 to 1, then a restart. Not all S12S's are fully LCD3 compatible, they all work but if not fully compatible they seem to have slight niggles passing the data.
 
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