Bafang M300 / Battery wiring problem

[goldenhawk]

Hi everyone.

I’m looking for some help please. Any knowledge most appreciated.

I have a Bafang M300 G360 36v motor.

I have a reading of 48 volt on a 36 v 13Ah 468Wh Battery @ Switched ON

Sorry if it’s long winded, but, without all the information what do you have to work with. Unless of course someone is good enough to look at their battery termination wiring for me.

I wish that I could get hold of the wiring schematics if anyone knows where to obtain them.

After everything that I am working on, I’ll most likely have enough information to draw my own schematic diagram lol. But for now, this is my problem to sort out at this moment if anyone can help, please.



The wiring from the Battery to the Motor have been messed up by someone else.

This how I have acquired the problem.



I have discovered that the original problem through investigation was a Hall sensor fault.

I discovered that the Battery polarity had been installed wrongly after checking the wiring due to an error 30 showing (Communication fault)

I have had to reverse the red & black to get correct polarity but now, I have got 2 soldered wires most likely in wrong positions.

I can’t see any obvious damage caused by this reversal of polarity.

I dare not connect the Yellow / Green and/or Red wires until I know the correct places for them to be.

I have in my sights…………...coming out of the Motor: -

3 white wires coloured at controller PCB *Y / G / R * – *For more information!

Inside the controller PCB- marked as follows: - Y = S2 / G = S1 & R = 4.3

These go into 4 PIN (3 Utilised) (Black female / male sockets)) travelling on then to the battery to smaller black socket.

This turns into 3 PIN plug Y / G & R wires which then go into only 2 wires Y & G terminating at the battery, for some unknown reason, the RED wire terminates at the plug ………...



For the Y/R & G wires I have to choose from:



Black + (Main 36v supply) Obviously not here!

Red - (Main 36v supply) Obviously not here!

1 x 3.6v Permanent Supply

2 x 2.9v Battery switched ON

Thanks in advance

Jim

 

[neptronix]

Pictures would be super helpful

 

[goldenhawk]

Are these of any use?

 

[DPC18RI]

It seems to me you have canbus motor. So your last picture marked "from motor" the 4 pin connector, only 3 pins used, are the CANH (green) and CANL (yellow) communication wires between controller and battery. And the thin red one normally has between 4 and 5V going from controller to battery.
But that thin red wire eventually does not reach your battery according to your pictures. The reason why that is i don't know.

Look at the 3 middle battery pins if you see any markings which can help you to know which wire, green or yellow needs to go to which pin. If no markings then you have to search the internet for pictures from your battery and hopefully some with the battery pin designation.

But in many cases a bafang controller can work without the communication wires between battery and controller. Just the thick red and black power wires from battery to controller is mostly enough to have the bike working (if bike has no faults).

You seem to have also a single blue? wire. Does the battery have a rear light build in at the back?

I think 36 volt controllers have mostly an overvoltage cut-off of 47 volt. You wrote your 36 volt battery delivers 48 volt ?? Are you sure it is a 36V battery (just asking).
Here you can find picture of M300 controller connectors, click the picture that mentions canbus.

The above is the only help i can provide because i have no M300 controller laying around to check.

 

[goldenhawk]

It seems to me you have canbus motor. So your last picture marked "from motor" the 4 pin connector, only 3 pins used, are the CANH (green) and CANL (yellow) communication wires between controller and battery. And the thin red one normally has between 4 and 5V going from controller to battery.
But that thin red wire eventually does not reach your battery according to your pictures. The reason why that is i don't know.

Look at the 3 middle battery pins if you see any markings which can help you to know which wire, green or yellow needs to go to which pin. If no markings then you have to search the internet for pictures from your battery and hopefully some with the battery pin designation.

But in many cases a bafang controller can work without the communication wires between battery and controller. Just the thick red and black power wires from battery to controller is mostly enough to have the bike working (if bike has no faults).

You seem to have also a single blue? wire. Does the battery have a rear light build in at the back?

I think 36 volt controllers have mostly an overvoltage cut-off of 47 volt. You wrote your 36 volt battery delivers 48 volt ?? Are you sure it is a 36V battery (just asking).
Here you can find picture of M300 controller connectors, click the picture that mentions canbus.

The above is the only help i can provide because i have no M300 controller laying around to check.

Thank you so much for replying and your valuable input.
You're right, it is canbus. There are no markings on the battery, so I'll put it out there as you suggest about the battery and see if I get a response.
Thanks again.
Jim

 

[goldenhawk]

I have a 36v battery providing power to a Bafang M300 360 BBSHD Mid-Drive.

It has 5 PINS (left to right) – negative – 3v – 3v – 3.6v – 36v (main pos.)
All except the 3.6 volt are live when battery is switched ON
3.6 v is permanent live, battery on or off

I have: green & yellow wires between controller and battery.
There is also a thin red wire that terminates at the connection just before reaching the battery.
I need to establish which wire, Green and Yellow needs to go to which battery pin designation on the 3 middle battery pins?
Also, should the Red be connected at all?
Anyone with similar connections on their battery?
Photo’s could potentially be useful too.

 

[offGridDownUnder]

You have not specified the controller you want to connect. You have not told us if this ever worked before, and what is changing (are you substituting an off-brand battery for the original, for instance?)

There is no requirement that wire color codes be honored between manufacturers, and in some cases the same manufacturer will not honor their own prior color code.

All up, please specify all the parts involved, the labels on each component, and pictures of the complete component.

 

[amberwolf]

I merged the new thread for this same thing to the original thread where you were already being helped. Please keep it all in one place so that those helping can see all the information and prior questions and responses, so that you can get the best help.

 

[amberwolf]

I have a reading of 48 volt on a 36 v 13Ah 468Wh Battery @ Switched ON

This indicates it is not a 36v battery, or it is damaged and severely overcharged in a potentially dangerous way that could lead to a fire (at any point in the future if not immediately).

I highly recommend rechecking that with a different voltmeter, or replacing the battery in your meter as a low battery will read high.

More questions to help clarify what you have and it's state so that we can better help you:

Did your system ever work?

If it did, what specifically happened or was done to the system before the problems began?

If it didn't, were all the parts from the same source? Were they all new? If used, were they supposed to be working?

If you are replacing the original system battery, such as by using a non-bafang battery on a bafang system, it may not work, as there are some systems that require specific communication between battery and system in order for the system to operate. I don't know your specific system, so it may not require this, but there are some that do.

 

[DPC18RI]

@ goldenhawk your 3th picture from post 3 seems to have the correct connection for the yellow and green wires as i measured it out (not visually checked) on a Veloci bike with a same EBT360-130L1SD1 battery 36V 13Ah similar as yours.
So the empty pin in that 3th picture from post 3 is - normally - for the thin red wire. But the question is why was the wiring changed and the red wire removed from connector??

You did not answer the question about the battery voltage you measured at 48 volt and if you measured it again to be sure?
Your battery with that type nr. is a 36V battery so if you really measure 48V that's not ok and something is badly wrong / dangerous with your battery.... See the post from amberwolf too.

To see if the bike can work, you can try with a lab power supply, set it at 36V and connect power supply to the thick red and black going to the motor. Leave the small green, yellow and red for the moment for what they are. i guess bike / M300 should normally be able to start up on a power supply set at 36 Volt and set over current (if possible) protection at 500mA that should be enough to let the bike be switched on via display. Maybe i can check that myself if i have time.

 

[goldenhawk]

Mentioned by DPC18RI the bike is actually a Veloci bike with EBT360-130L1SD1 battery 36V 13Ah
It is equipped with a Bafang M300 G360 36v motor. I'd love to know/ see the wiring connections / voltages on yours.

I will check with a different voltmeter though and replace the battery in my meter just for peace of mind and confirmation.

To answer a couple of questions I've noticed.
the e-bike etc was actually donated / given to me as a non-runner to see if I could sort out repairing it for my personal use.
It is a non-runner, this is a project for me and if all else fails, it can go to the great e-bike scrapyard in the sky.
This is a project for me.
Display error 08 was showing so I tested the hall sensors and surely enough No. 2 was not working.
I replaced this to then have error 10 which is a communication problem apparently.
I have gone front to back checking all wiring. All seems okay.
I checked the battery only to find out that it had been refitted by someone with REVERSE Polarity and the problem that I have with these Yellow / Green & Red wires.
I haven't seen anything that has been fried as of yet. Just working my way through slowly and methodically.
I don't want to throw good money after bad, I've spent very little so far, so I've lost nothing, but I love a challenge.
Thank you all for your comments, it all builds towards the bigger picture.

 

[DPC18RI]

Usually error 10 is motor temperature fault. Motor hot or a temp sensor / sensor wiring fault. maybe happened when you changed the faulty hall sensor?

Anyway, I used a lab power supply to provide voltage to the black and red power wires from the controller. As expected the bike can be switched on.

I disassembled the rear rack to visually check the wiring...
In the case for this specific battery and veloci M300 canbus motor, the thin red wire go's the whole way to the rear rack but is not connected to the 5 pin male connector. Only thick black negative, yellow canL, green canH, and thick red are connected.