DIY Fix for BBS02/BBSHD Pedal/Throttle Issue

thetrevdev said:
I just installed my first BBSHD yesterday. While a blast I am finding it difficult to control speed.
Can you describe how it is supposed to work?
I haven't installed my disc brake sensors yet so I am avoiding PAS > 0.
I am pedaling in PAS 0 and trying to manually control the assist but it is jerky and feels like 100% throttle.
I assumed this is just the way it is. Is this related to the issue you are discussing here? I have nothing to compare this to and don't know how it is supposed to work.
That sounds like mine was. It's possible there are some settings in the programming that might help, but I tried a lot of things with no success. To disable the PAS, I found all you need to do is unplug the PAS sensor inside the controller housing. This makes it pretty easy to put back later. I ran like that for about a year until I installed the fix.

You could try the higher PAS settings without using the throttle and see how it works. Just remember to pedal backwards to instantly stop the motor.
 
That was really helpful. I didn't know you can pedal backwards to stop the motor in pedal assist.
After trying pedal assist on my commute it confirmed I really just want to use throttle to control my level of assist. I don't to worry about managing my gears when coming to a stop or worrying about power being applied when pedaling slow around obstacles etc. I will consider unplugging my PAS sensor.
 
Unplugging the PAS sensor is pretty easy. I recommend unplugging the battery first before working on anything. The hardest part is just removing the crank arm and chain ring to get access to the controller screws. My bike has a 30T chain ring, so much easier.
Remove the 3 screws holding the controller on and carefully pull it away from the motor. Unplug the PAS sensor (black connector). The plug may be stuck in with potting, but it comes out pretty easy. Be careful to avoid pinching any wires when placing the cover back on.

Down the road, you can consider doing the fix described in this thread. Having both PAS and throttle working is nice. If I set the PAS level to 0, it behaves the same as unplugging the PAS sensor and I use that for technical off road stuff.
 
thetrevdev said:
Do I disconnect the entire 4 pin connector or the grey wire wire in the connector?

You can just unplug the whole connector as far as I know. When I did it, I cut the grey wire, but it seems you get the same result by unplugging the whole thing, which is a lot easier to put back later.
 
Just installed new controller HD. ( just a note, Luna is sending controller removed from a complete kit - it has broken connector - that locking part which holds connector in place - I dont find this professional from Luna!)

Also has spotted strange behaviour of throttle. It just turns on on full throtle. Throttle overrided PAS with old controller.

This must be a change in firmware, any chance to program old firmware using programming cable?

Anyway I had an issue that motor suddenly went on low power and also not smooth, after while it turned off. But I was able to turn it on again, but with low power and not smooth again. I have found one melted anderson connector. Anybody had similar experience? Anybody want old controller HD? I think fault was just in that melted connector and it lost contact.
 
DaDo.Bzz said:
This must be a change in firmware, any chance to program old firmware using programming cable?

Anyway I had an issue that motor suddenly went on low power and also not smooth, after while it turned off. But I was able to turn it on again, but with low power and not smooth again. I have found one melted anderson connector. Anybody had similar experience? Anybody want old controller HD? I think fault was just in that melted connector and it lost contact.

No, only Bafang has the firmware and they aren't sharing. The firmware gets flashed using a different connector that's located on the board.

Haven't heard of any phase wire connections going bad before. Possibly it wasn't plugged in all the way or one of the contacts wasn't fully seated.
 
Hello Fechter

Yes, could be there was loose contact so it melted.

Anyway I did a ride yesterday with new controller and it is really bad. It is lalmost like on/off when you pedalling (to be precise throttle is active on 1000 - 1550 W) - high consumption then and also high stress when pedalling with low assistance. Omg, how they could broke something what worked well?!

Other observation. Looks to me also low voltage protection works different. With old controller it start to ramp down overall power while you were closer to cut of voltage. Now nothing and my bms came to play and turnedoff everything including light while I was downhilling in 50kmh- scary!
Had to go with phone light as looks like bms went active just after plugging the charger.
 
The low voltage cutoff is programmable with the Bafang software. Sounds like it is set too low and the BMS is cutting off first.

If you have the Bafang software and programming cable, you may be able to read the settings from the old controller and copy them to the new one. You may see some improvement by simply changing some of the settings, but I don't know exactly what needs to be changed.

Bafang really screwed up when they did that version of firmware. Yours sounds exactly like mine was before I did the fix. You could do the fix or unplug the PAS sensor and run throttle only.
 
I received a new BBSHD controller from Luna the other day. It had the throttle problem but a friend put the “fletcher” fix on it. Now it’s nice and smooth.
 
Hello Fechter.

Yes, I copied exactly same setting to new controller and was surprised when controller didnt cut off motor.

Your tweak is great, just not sure if I wanna again dismantle it from bike and get to wires. Bloody bafang, did they even test it before releasing this new firmware?!
 
I've resorted to unplugging the pas on the new controllers. The newest issue I'm running into is I've never bothered with the speed sensor. I don't run a display (bypassed) so ive always just clipped the speed sensor off. With these new controllers, if it experiences an error 21 (not sensing magnet at speed sensor) then it will shut the motor down. It has never done that with the 6 or so motors I've had before. It would be awesome if I could now somehow bypass the speed sensor (short a couple of wires or something). Anyone know how I might accomplish that?
 
gburb said:
I've resorted to unplugging the pas on the new controllers. The newest issue I'm running into is I've never bothered with the speed sensor. I don't run a display (bypassed) so ive always just clipped the speed sensor off. With these new controllers, if it experiences an error 21 (not sensing magnet at speed sensor) then it will shut the motor down. It has never done that with the 6 or so motors I've had before. It would be awesome if I could now somehow bypass the speed sensor (short a couple of wires or something). Anyone know how I might accomplish that?

See this topic:
https://endless-sphere.com/forums/viewtopic.php?f=28&t=90821&p=1406842#p1406842
 
About the transistor to be used, I have a MPSA06 and a MPSA14, can any of them replace the others listed in previous post?
 
Mpsa14 should work fine. Just double check the pin out. Some may have the legs arranged differently.
 
Thanks. Just got a second new controller, 36v500w, marked october 2018, think that best way is remove pot from the area where cables are welded to board, the zone where cables enter the controller is a mess and I fear that if I remove the pot there it will be impossible to have it waterproof again unless I buy the Magic Rubber compound. Do you have info if Bafang reverted the firmware mode? Maybe will test once "as is"...

Another thing, are you aware if there are posts im this forum about modifying a 750w with a 500w controller? Searched but could not find. Here in italy a few ppl did it, to have less rpm and less heat when climbing step hills.
 
Definitely test it before digging into it. I haven't run across any 500W versions. Not sure, but you may be able to reprogram it to be the same as the 750W.
 
I see that the Domino throttle has a micro switch built in. Couldn't this be used to switch off the PAS as soon as the throttle is activated?
 
espresso said:
I see that the Domino throttle has a micro switch built in. Couldn't this be used to switch off the PAS as soon as the throttle is activated?

Yes. It should work perfectly and not require cutting into anything.
 
espresso said:
I see that the Domino throttle has a micro switch built in. Couldn't this be used to switch off the PAS as soon as the throttle is activated?

can you link where i can buy that throttle from please
 
JPLabs said:
To use this throttle switch, we need to break out the PAS wire inside the motor, and switch that, right?
You need to just tap into the black and grey wires on the PAS connector. The switch closes when you open the throttle so we want to ground the grey signal line.
 
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