Cycle Analyst setup with PAS only

[alfy22]

Hi,

I recently finished my bike build but have a problem that I was hoping someone could help with. The power response from the motor is very underwhelming and is giving me assist speeds of only 8-12 km/hr on the flats. This is my current setup:

- Bafang G310 rear hub motor, standard wind
. Grinfineon 20A controller
- Cycle Analyst V3
- 36V 13.8 Ah battery that according to the specs should deliver 20 continuous discharge current.
- 24 pole PAS sensor only (NO THROTTLE installed!)

I have tried to follow the CA unofficial user guide setup as closely as possible but as I don't have a throttle I was not able to adjust the throttle-in and out settings as per the manual an left them default. I am wondering if this could be the problem? Below is my current setup. I have tried putting Throttle in setting to zero (disabled) and setting the power limit on PAS setting very high - the CA shows the power going up to about 800 W but this doesn't translate into any speed whatsoever on the bike. I have also tried the PAS THO mode with similar results. The CA shows a voltage of 40V an current of 18-19A when assisting in PAS mode so the controller appears to be getting the correct supply, it just isnt being transferred to speed on the bike.

Any ideas on what could be wrong here?
Thanks!
Kris

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[amberwolf]

- 24 pole PAS sensor only (NO THROTTLE installed!)

I have tried to follow the CA unofficial user guide setup as closely as possible but as I don't have a throttle I was not able to adjust the throttle-in and out settings as per the manual an left them default.

The throttle in wouldn't matter, with no throttle, but you should still adjust the throttle out to be whatever your controller requires for it's throttle input range, as that is how the CA tells it to move, when the CA gets the PAS info from it's sensor input.


I see you use 6 poles (pulses per rev) on the speed sensor. That means you have six magnets on your wheel to activate the speed sensor on the frame/fork a total of six times each wheel rotation.

If you do not have six magnets, you would need to change that number to whatever you actually have.


The Assist Scale RPM is set to zero. AFAICR that means it won't provide any assist? IIRC for max assist I was advised to set it to 40 for my extreme setup on my trike (haven't had a chance to go back and work with it in a while, so don't know how it'll work out).

 

[alfy22]

Ok fixed! It was an easy fix actually - I neede to set the RShunt value on the CA3 to match the shunt resistance that is lasered on the motor controller label (5.4 mohm in my case) and not leave it at the default value of 1.000 mOhm. If the RShunt in the CA doesn't match that of the shunt it is plugged into, then all the power and amps readings will be similarly mis-scaled in proportion - that was the problem.

Kris