Bafang Ultrawithout hall sensors

garyal1

100 W
Joined
May 18, 2018
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110
I was in the process of converting a second Bafang Ultra bike from 48 volts to 72 volts with the Grin PR and CA3. I did one already at 60 volts and liked it so much, I bought all the items from Grin and a large capacity triangle battery.

When I went to remove all of the internal Bafang controller and such, I found this unit is different from my 1st one. It does not have hall sensor wiring! It has a little magnet on the end of the motor shaft and that spinning gives some signal to a board and that somehow simulates the 3 hall sensors. This cannot be used with the PR and CA 3.

So I tried doing the sensor-less auto tune and it does run the motor. It does so after some bang and pops. Not a smooth start up like my other unit with hall probes.

Can anyone tell me if this will give me a lot of problems? Should I just abandon this project and leave it at 48 volts with Bafang controller and 30 amps? Should I go ahead and install it in sensor-less mode without hall sensors? It seems like it would not be good unless I only had the motor start after pedaling.

Can I buy some hall effect sensors and install them into the windings?

Looking for advice......
 
garyal1 said:
It has a little magnet on the end of the motor shaft and that spinning gives some signal to a board and that somehow simulates the 3 hall sensors. This cannot be used with the PR and CA 3.
Why not?

If it gives 3 outputs that match the phase positions, then it doesnt' matter if it's actually hall sensors or not, as long as the signals are the same and the same timing.
 
The reason it cannot be used is because it is all internal in the control board for the stock Bafang controller which I was going to replace with the PR and CA3:

1) The control board will be removed.
2) The circuits are internal to this board so even if I could leave the boards in the system I could not get the singals out to the Grin unit.
 
People will say that you can wire up that lower board to work with another controller. However this is something I have been actively trying to figure out since I got mine, to no avail so far. Problem as I see it is there are just too many iterations of these controllers, and not everything works the same as the last version ;)

That being said, the sensor less running with a phaserunner is *ok*. By no means would I prefer it over the hall versions. Having mine for over a year now, I have racked my brain and spent many hours over settings and tweaking trying to get it running perfectly, never has happened,. Always a jerky start, unless you cripple it with a huge gradual throttle setting or something, which no one wants.
But it is possible to still run and you learn how to negate the bad with different things, and it is tolerable in sensor less operation, with the phaserunner anyways, cant speak to any other setup.

Just some information for ya anyways, sometimes its hard to find definitive info with this motor, I suspect mainly because of how many different iterations there is at this point.
 
People will say that you can wire up that lower board to work with another controller. However this is something I have been actively trying to figure out since I got mine, to no avail so far. Problem as I see it is there are just too many iterations of these controllers, and not everything works the same as the last version ;)

That being said, the sensor less running with a phaserunner is *ok*. By no means would I prefer it over the hall versions. Having mine for over a year now, I have racked my brain and spent many hours over settings and tweaking trying to get it running perfectly, never has happened,. Always a jerky start, unless you cripple it with a huge gradual throttle setting or something, which no one wants.
But it is possible to still run and you learn how to negate the bad with different things, and it is tolerable in sensor less operation, with the phaserunner anyways, cant speak to any other setup.

Just some information for ya anyways, sometimes its hard to find definitive info with this motor, I suspect mainly because of how many different iterations there is at this point.
Hey I guess the pinout I gave you didn't work? I don't think the canbus had a revision change so I'm surprised to hear it didn't (although the 750w and 1000w are different so just to confirm you do have a 1000w right?). I do want to make sure the original controller still works with the motor aka the magnet didn't get tweaked and uncalibrated for the lower board? And that when you were testing the motor it was all closed up, if not the magnets not aligned with the sensor. I seriously suggest joining their discord (link in the description) and I'm certain they can help get it running well with the halls
 
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