Preliminary advice for fitting a Bafang bbs02 motor only

[wheeliepete]

There's too many unknowns and variables to say if the drive is faulty or not. Best guess is a faulty controller as this is the most common failure. I can understand how you saw this as a good deal, but as a good complete s/h unit sells for around £250, you can maybe see it wasn't such a bargain. Returning it might be your best option.

 

[Gully]

I applied 3v across throttle and ground via an external psu. Again nothing with cranks still or turning.

Pete, what exactly does 's/h unit' refer to?

 

[wheeliepete]

Pete, what exactly does 's/h unit' refer to?

Second hand, complete with all the parts to fit to your bike.

 

[Gully]

Ah OK. Haven't come across any second hand kits. Where have you seen them?

Would have been about £200 all in for the kit so not a huge saving on 250, but still a good deal if it had worked like advertised and much cheaper than new.

Guess I'll be looking for another second hand kit/motor now then.

 

[harrys]

Well, I did try it on mine. Put in the jumper, lifted the rear wheel, and my motor kicked in when I cranked the pedals. Also seen one video on youtube which confirm this works.

If your seller is close enough, maybe he can prove it runs for you.

 

[jarob10]

Buy another bbs but keep the existing unit for spares?

 

[Gully]

Hi all!

I didn't give up on my BBS02 in the end... I negotiated a partial refund from the seller and we settled at that. I like fixing things, at least if and when I succeed! So I proceeded to order the other bits I need, hoping to diagnose the issue.

All hooked up with display (admittedly a second hand C901, new harness) I'm getting error 30. Googling it suggests either:
Faulty display (unlikely as we've already established motor not working),
Faulty harness (unlikely as brand new),
Faulty Speedo (possible as came with motor and casing is partly missing. But it's the same with Speedo disconnected),

** Do I need a working Speedo connected for BBS02 to run? **

Or faulty controller (probable).

So I'm now going to try opening up the controller. Ideally I'd still rather fix the controller than buy a new one! I don't mind soldering if required.

I understand Er30 is communication error between controller and display. So what kind of controller problem could this include? Could it be a blown FET or would that have different symptoms? I haven't noticed any resistance turning the cranks, but may need some guidance to make sure I'm doing that test right? Any more advice on diagnosing controller faults?

Thanks as always!

 

[Nealh]

On my bbs01 I get an error code 21 and no power with no or faulty speed sensor.
Error 30 is a new controller or jst connector not full home in controller.

 

[Gully]

Thanks for your reply. Don't understand what you mean by "not full home in controller" though. And which connector is the JST?

Cheers.

 

[Nealh]

When you remove the controller there is a white jst connector block 5 or 6 wires (hall sensors) which plugs in to the motor , this is usually gunked with white silicone and sometimes prevents the connector from fully seating and can give false error codes.

 

[Gully]

Cool, yes, I have seen these. Will try to relocate tomorrow. Er30 is displayed just the same with the controller loose from motor. The display comes on showing no battery for one moment then goes off with Er30 in the corner.

By the way, can you program BBS loose from Motor? Also, does it need to be connected to battery? I bought a USB programming cable.

 

[wheeliepete]

can you program BBS loose from Motor?

Never tried it, but should connect with your computer ok, and yes, connect your battery also. If you are on a tight budget , you may want to consider fittting an external controller.

 

[Nealh]

You have to disconnect the white connector and remove the silicone from both parts of the connector, if it does not cure your issue then a new controller is needed.
Any programming needs battery supply.

 

[Gully]

Cleaned up the silicone, also left it all in front of a dehumidifier for a while because I read someone else's worked after a drying. No avail.

I have been looking at an external controller solution. Trouble is, I've invested in loads of Bafang parts now. Think if I had known about the external controller solution I would have done that in the first place....

Does anyone know of any ways to get Bafang sensors/LCD to work with an external 3rd party controller? I'm guessing LCD is a lost cause.

Money is very tight ATM so would probably have to wait until next month for a Bafang controller + another month to arrive from China! Maybe I should sell Bafang parts and go external?

 

[Nealh]

Woosh bikes sell some BBS controllers so speak to them, if in stock you would have it in 24/36hrs usually.

 

[Nealh]

For external controller you would need a matching lcd and controller, KT are easy to get hold of.
The phase , power & sensor wires should relatively easy to extend and couple to a controller. PAS is internal so you would need to rig up a PAS disc on the LH crank.
Speed sensor and throttle should be easy only three wires to hook up to controller wire connectors.
The hardest part is making a nice job of the wiring to and from the mid drive, possibly spiral wrap would help to tidy/keep wiring together.

 

[jarob10]

Without knowing what caused the mysterious err30 fail in the first instance, there’s a chance your replacement controller would go pop too.

I had a couple of replacement BBS-01 Bafang controllers suffer repeat err30 failures before replacing with a KT controller. No problems since. It’s not cheap though as you’d also need an external PAS, an LCD-3 screen, brake levers and a motor extension lead to solder onto your broken Bafang controller connectors. You’d need half a day soldering it all up too.

 

[Nealh]

It will depend on if a julet controller is used or the old sm connection type.

 

[Gully]

Yikes, multiple er30 blown controllers doesn't sound fun! Can we not get to the bottom of what's going wrong on the controller? There's plenty of info on swapping FETs online, if only an electrical engineer would solve this problem for us!

My thought re external controller was cheap eBay one. I imagine most won't require an LCD. I didn't realise that there were 3rd party externals made for the BBSs!

If I was to try the cheap eBay controller route, I'm not sure how to select a safe power (aren't many available at 750w). Would fitting one rated above 750w risk sending too much power to the motor, damaging it? Or if I fit one rated below 750w would the motor pull too much current through the controller and blow the controller? I'm thinking the former?

I've read that square-wave controllers don't run well, but you can run without hall sensors. If a controller doesn't specify sine or square-wave do you think I can assume it's square? And am I right in thinking the BBS02 is brushless?

Cheers

 

[Nealh]

When selecting a controller ignore the Watt's rating instead select the controller for it's voltage & amp rating suitable to your existing set up.
If not sure of controller description look at its wiring, apart from a 4/5 wire led/lcd connector you need to check whether there are 6 separate small motor hall wires either loose or in a square shaped connector. Hall sensor standard colours are Red, Black, Green, Blue, Yellow & White.

All BBS are brushless hall sensored drives.