New Bafang BBSO1 350W 36V connected to battery and throttle only motor not responding

Presuming the system has never worked yet, then does the system's display turn on and show you anything?

If so, are there any error codes on the display?

Does the battery meter show a normal level?

Is the battery fully charged, does it have the right voltage at the output, and is it the correct one for this system? (meaning, if it's a 36v system, is it using a 36v battery?)

You can use the multimeter on 200VDC to test the battery output by connecting the red meter lead to the B+ of the battery, and the black to the B-. (see the multimeter's instructions on how to set it up to measure DCV; they are all a bit different so I don't want to give you wrong instructions for yours).


To use the motor tester you'd have to disassemble the middrive, so I don't recommend that.

philg said:

I have only the throttle and battery connected to the motor and those are the only attachments
made when it goes on the bike.

Click to expand...

Not addressing your issue but just confirming that when it goes on the bike you’ll be connecting a speed sensor in addition to your battery and throttle, correct?

E-HP said:

Not addressing your issue but just confirming that when it goes on the bike you’ll be connecting a speed sensor in addition to your battery and throttle, correct?

Click to expand...

amberwolf said:

Presuming the system has never worked yet, then does the system's display turn on and show you anything?

If so, are there any error codes on the display?

Does the battery meter show a normal level?

Is the battery fully charged, does it have the right voltage at the output, and is it the correct one for this system? (meaning, if it's a 36v system, is it using a 36v battery?)

You can use the multimeter on 200VDC to test the battery output by connecting the red meter lead to the B+ of the battery, and the black to the B-. (see the multimeter's instructions on how to set it up to measure DCV; they are all a bit different so I don't want to give you wrong instructions for yours).


To use the motor tester you'd have to disassemble the middrive, so I don't recommend that.

Click to expand...

amberwolf said:

Presuming the system has never worked yet, then does the system's display turn on and show you anything?

If so, are there any error codes on the display?

Does the battery meter show a normal level?

Is the battery fully charged, does it have the right voltage at the output, and is it the correct one for this system? (meaning, if it's a 36v system, is it using a 36v battery?)

You can use the multimeter on 200VDC to test the battery output by connecting the red meter lead to the B+ of the battery, and the black to the B-. (see the multimeter's instructions on how to set it up to measure DCV; they are all a bit different so I don't want to give you wrong instructions for yours).


To use the motor tester you'd have to disassemble the middrive, so I don't recommend that.

Click to expand...

Hello amberwolf,
I don't have a display as I didn't purchase one with the kit.

Yes the battery was at 39.4V or so at the time it was tested and yes it is a 36v battery and I use it regularly on my bike with the GNG setup.

I measure the batter state with a 150A Watt meter and power analyzer.

E-HP said:

Not addressing your issue but just confirming that when it goes on the bike you’ll be connecting a speed sensor in addition to your battery and throttle, correct?

Click to expand...

Hello E-HP,
No I won't be connecting a speed sensor when it goes on the bike only the throttle and possibly the brake activated cutoff.

philg said:

Hello amberwolf,
I don't have a display as I didn't purchase one with the kit.

Click to expand...

Bafang BBS01B needs the display attached to power up the controller. When the display turns on, it connects battery voltage to a certain lead in the connector.

You can jumper the display connector to start the controller. That is a male connector with five pins, but unless you have the right kind of jumper wire, it's too easy to touch the wrong pin and blow up the electronics.

docw009 said:

Bafang BBS01B needs the display attached to power up the controller. When the display turns on, it connects battery voltage to a certain lead in the connector.

You can jumper the display connector to start the controller. That is a male connector with five pins, but unless you have the right kind of jumper wire, it's too easy to touch the wrong pin and blow up the electronics.
View attachment 351699

Click to expand...

Hello docw009

Thank you for that particular bit of information. I did wonder if that could be what was happening. I had heard reference to that being the case but also read of others not using a display.

The wire in the image shows it to have JST connectors?

Will attach an image of one of my plugs with 8 pins and an accompanying image I found of a Luna Cycles plug.
Given that the Luna Cycles plug is from a Bafang style motor, would their pin attributes be the same?
Numbers 1,2, and 3 I have no idea what they ascribe too, but the rest seem self explanatory.

Would it be correct to use pin 7 (throttle signal) on the (main harness plug) back to the throttle in place of the blue signal wire on the separate (throttle plug)?

philg said:

No I won't be connecting a speed sensor when it goes on the bike

Click to expand...

I can't recall for sure about the BBS01, but some middrives will time out and cease assistance / shutdown if they don't receive a speed sensor signal.

If you run into this issue, you can build a 555 timer or other pulse-generating circuit to fake this signal if you wish, but a non-variable signal may change the way the system responds.

philg said:

I don't have a display as I didn't purchase one with the kit.

Click to expand...

As noted by docw009, the display is normally what is used to turn the controller on.

While you can jumper to bypass that**** you won't be able to change assist level from whatever the default power-on level is, or change any settings, etc. Note that some systems power up in a no-assist mode zero and you have to press the up button on the display once to get any assist, every time it is turned on, as a safety feature. I don't know if your version of the BBS01 requires this or not (Bafang changes things about how all their products work, are made, and are wired, without notice to anyone).


****I don't know which specific pins on your specific connector, but it should be B+ (battery positive) and "lock" or "ignition" or "KSI" (whatever this specific system calls it). If you short B+ to anything else you'll damage the controller.

The display raises the PL line from 0 volt to battery voltage when it powers up. Battery is P1 on those diagrams. WIthout a display, connecting the two powers up the controller. This is how most controllers and displays interact, The TxD and RxD pins in the display connector send serial data packets between the controller/display, The Grd pin is the ground pin. That covers all five pins.

Yes, it would be easier to put jumpers into the main harness. But then you also have to stuff the three throttle wires into ground.+5V and signal. Double check everything. If you put battery voltage to any other pin but PL, you'll destroy the controller. just trying to diagnose whether it works.

docw009 said:

The display raises the PL line from 0 volt to battery voltage when it powers up. Battery is P1 on those diagrams. WIthout a display, connecting the two powers up the controller. This is how most controllers and displays interact, The TxD and RxD pins in the display connector send serial data packets between the controller/display, The Grd pin is the ground pin. That covers all five pins.

Yes, it would be easier to put jumpers into the main harness. But then you also have to stuff the three throttle wires into ground.+5V and signal. Double check everything. If you put battery voltage to any other pin but PL, you'll destroy the controller. just trying to diagnose whether it works.

Click to expand...

Well I was about to give up on this and go back to the retailer and buy one of those "big bulky displays" that I would have no need for the information they provide as well as being exposed to damage.

A quick skim of the contents of the link you sent, there is a breath of hope. To understand it's scope I will have to very carefully read and digest.

One or two questions: You mentioned 5 pins and the link you sent also talks of 5 pins at the controller end. The image I sent is my plug with 8 pins including ground so does that terminate as 5 wires at the controller?
When you say "If you put battery voltage to any other pin but PL, you'll destroy the controller." You mean battery positive (Red) wire to PL only.

The other question is: In the link it mentions BBSHD and BBS02, is this meaningful when it comes to the BBS01 that my motor is?

Here's a clean solution for you. Buy a BBS program cable from amazon. I have this one and it was only 14 bucks. It makes the jumper connection for you. People use it as a backup for rinning the bike with broken screens, but it is intended be connected to a android or a PC for setting parameters on the BBS. No need to make hodgepod connections to your motoir harness.

docw009 said:

Here's a clean solution for you. Buy a BBS program cable from amazon. I have this one and it was only 14 bucks. It makes the jumper connection for you. People use it as a backup for rinning the bike with broken screens, but it is intended be connected to a android or a PC for setting parameters on the BBS. No need to make hodgepod connections to your motoir harness.

Click to expand...

The cable the link refers too is a 5 pin female, my main harness terminates in 8 pin female.

There is another small problem, I may have to buy a hard drive to put Windows xx on.
I don't know anyone who would allow me to install a program on their machine, unknown to them and I don't have a smart phone.
I will keep looking within the Linux community for a work around and there is a possibility of getting the program to work through an application called Wine for those who are reading this and know Linux.

Perhaps I've made a mistake in thinking a BBS01B is like an BBS02B except for a smaller motor,

Those two three pin connectors in the BBS02V/BBSHD are for a gear sensor and speed sensor, There is a 4n1 harness off the 8 pin plug to reach the display, throttle, and brake levers on the handlebars.

Nonetheless, I doubt that the connector in your picture, which is labelled G, S, V is for throttle. There's no point in having a throttle connection on the bottom of the motor, when they sell a harness intended to reach the handlebars where you install the throttle.

docw009 said:

Perhaps I've made a mistake in thinking a BBS01B is like an BBS02B except for a smaller motor,

Those two three pin connectors in the BBS02V/BBSHD are for a gear sensor and speed sensor, There is a 4n1 harness off the 8 pin plug to reach the display, throttle, and brake levers on the handlebars.

Nonetheless, I doubt that the connector in your picture, which is labelled G, S, V is for throttle. There's no point in having a throttle connection on the bottom of the motor, when they sell a harness intended to reach the handlebars where you install the throttle.

Click to expand...

Yes shortly after my reply previously I had a look for 8 pin cables and soon realised I needed a breakout cable for the 8 pin female connector on the motor, so have ordered a 1-4 harness cable and programming cable for expected arrival within two weeks.

I will be only be using the display connector and possibly the brake actuated cutoff as already have a small speedo/bike computer that gives me all info I need for commuting and I can put it in my pocket when parked in public.

The wires coming out of the motor did confuse me and I agree with you, why have such a short throttle connector. The labeling on the orange connector is my work after noticing a similar cable on a Bafang type motor from Luna Cycle.

Well thank you docw009 for all your help and advice and also to amberwolf for helping me look at this with more clarity.

Shall I mark this as solved or wait till I see the motor spin up?