Bafang m820
- Thread starter Vsoria
- Start date
Check the connector, I had a similar issue on my side, I have to turn it to the left and right to make to charge.
Ok, I will try that. Thanks.
So, I put a different charger on the battery, the led was red for a very short period before it turned green. The reading from the battery was 50.4. This was with the motor, battery and wiring removed from the bike. I checked all the wires for breaks and continuity, I found that the cables connected to the charging port were in poor condition with broken strands, so cut the bad wiring and resoldered them to the charging port. I also cleaned all the connections with isopropyl alcohol. I reconnected to besst I got readings from the controller and the display. I reconnected everything up and the display and the remote worked, the display showed 100% battery. I rebuilt the bike and it seems to work. I will take it for a longer test run later. Hopefully I won’t have any further problems. A big THANK YOU to everyone who made time to respond with suggestions 
So, I tried to switch on the motor and nothing happened. I plugged in the charger and the motor came on I checked for errors on the display - There were no error codes displayed when I used the best tool, see photo Showing codes, from what I can find these codes relate to brakes and throttle? None of which are attached to my bike. This is frustratin. Any ideas?
Not an expert on this, but that list is error codes you have had. No. 21 is easy, that is speed sensor fault. No. 09 is bad, that would mean motor phase wire failure. Still I have had 09 also, but only for a second or so when I power up the system some time ago. It still remains in that list, even if not active any more. I would guess there is someting wrong with your wiring, you can check all cables, to battery and display. It can also be in the wiring inside the motor.
Maybe check if it is a warranty issue where you bought it, before opening up the motor.
Error code list:
Error codes
Thanks for your response Freda, I had previously checked the cables visually and had checked for continuity on the charging and battery wires with a multimeter, since my last post, I have been able to switch the motor on and off several times and had a short ride locally, there seems to be a pattern, it rides ok for short distances then the next time I take it out it doesn’t work
An update, the bike switches on when I connect the charger and continues to work when I ride it, but if it has been switched off for a while it will only come on when the charger is connected - except the last time I tried it, it would not switch on with the charger connected. 
The battery is probably in « sleep » mode, is it a Bafang battery ? For instance, I have a light connected directly to the battery, and I can see that the light stays on for few minutes after the switch off, then I have to turn the bike on to switch on the light again.An update, the bike switches on when I connect the charger and continues to work when I ride it, but if it has been switched off for a while it will only come on when the charger is connected - except the last time I tried it, it would not switch on with the charger connected.
Thanks for responding, it’s not a bafang battery. I again connected the charger and the bike switched on, this time the charger showed a red led and stayed red even when the display showed the battery at 100%. I was able to switch the motor on/off with the charger disconnected. Will check again later too see if it switches on without being connected to the charger. I am assuming its a bad connection somewhere
I have contacted Linda at szzs to make her aware of the issues, the last communication we had she implied I may have to return the motor.Check in the cef50 thread, I’m sure this issue has been discussed already but I can’t remember…
Sorry that I cannot help more, my memory is very shitty
Have you checked your connections ? I remember there were issues about the wrong cables.
I think it was early in the thread
My bike seems to be working again; it switches on and off - even after leaving it for a day or so and it rides well. I haven’t done anything to it other than ensure the battery was fully charged before I used it. I have no idea what the problem was or, if it will return. Another thing, whenever I have connected the charging cable to the socket on the frame or when I have reconnected the battery cable to the motor, there is always a ‘spark or ‘snapping’ type noise, it has always done that, is that normal?
cheers
cheers
plug the chargeur to the power supply before the batterie
Imendiolea
New Member
I once used a wrong charger and it made that sparking noise. I would check if the charger is correct.
The charger is the one supplied when I bought the battery, motor and frame, I can only assume it’s the correct one
I spoke to soon, its not working. Has anyone got any advice on how I can check if the bms is faulty? Thanks.
If you bought it as a kit it is surely a warranty issue. Contact seller for more instructions.
souftosouf
New Member
Hello everyone. I just took out my CEF50 M820 for a ride and i have some questions for you.
I'm on 48 12 E10 2006.1. Thanks for your help.
- I dont know how to explain it, but torque sensing seems a bit limited. Its giving me a small range of adaptiveness : Let's say i'm on PAS1 and it's set to 20% of max power. It will give me between 15% to 20% instead of a 0-20% range. Same with all other PAS. Is there a way to extend this range ? I dont want an emtb mode, but a least a 20% range.
- I was on a climb (after a 1h ride) and its started to make a really loud noise. I was on a medium cadence (<80) but it made the same noise as if i was overpedaling. I stopped for a sec, and it never made this noise again. Was it overheating ?
- My motor is vibrating at low cadence (High torque, low cadence. I feel like the motor is struggling to start), do you experience the same thing ?
- Overrun is horrible, which firmware has the lowest ?
I'm on 48 12 E10 2006.1. Thanks for your help.
My m820 has a funny problem, just wonder if any encounter this before.
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M820 sudden power lost n back again.
Yesterday my M820 suddenly power cut when cadence it's low during climb when I set to B. Then I rest for a while and test it again on flat surface , on B when I pedal at high cadence , my leg can feel the power was not as smooth as before, it's goes off or lost power a little and back again...
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temon10
Well-known member
just enjoy it man, 2 of my m820 already run over 1500km. later when reach 200km will regrease.
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