Known Issues & Problems with Bafang Products + Help, Solutions & Fixes

[Ben1331]

Hi guys - I have an Ebike powered by a 36V bafang cr s104.250.sn

was working great for over 2 years but has now developed an issue

when you power it on the battery and power indicators light up as normal but after 10 seconds the power indicator drops to 0 and flashes - the bike produces no power and the buttons to turn up the power don’t respond once it hits 0

I have tested the battery and it seems fine holding stable at 42V fully charged (I’ve replaced cells in previous e bikes so it doesn’t seem to me as a dead cell anyway)

anyone have any ideas what would cause this ?
I assume it’s either going to be battery/controller/motor or a sensor issue

any help would be much appreciated
regards
Ben

 

[john peck]

Check the power connector, it may not be fully inserted or maybe a bent pin. If it had been
improperly connected you´d probably get an error code. this happened to me the other day;
after having removed the wheel i did not get the connection completely pushed together. Check
all your connections

 

[Ben1331]

I have disconnected and reconnected all the connections to the controller (none look corroded or dirty)

the battery has been in and out a few times while testing the cells so I assume that connection is okay too

the issue is very consistent

You power on the bike

Both meters light up and you can move the power meter with the buttons

after 10 seconds the power meter goes down to 0 and then flashes the bottom light 4-5 times and then goes off and the up and down buttons are then unable to raise the power

the battery status stays powered and doesn’t change

Can you check error codes on this system with no display ?

Check the power connector, it may not be fully inserted or maybe a bent pin. If it had been improperly connected you´d probably get an error code. this happened to me the other day;
after having removed the wheel i did not get the connection completely pushed together. Check
all your connections

 

[john peck]

I have disconnected and reconnected all the connections to the controller (none look corroded or dirty)

the battery has been in and out a few times while testing the cells so I assume that connection is okay too

the issue is very consistent

You power on the bike

Both meters light up and you can move the power meter with the buttons

after 10 seconds the power meter goes down to 0 and then flashes the bottom light 4-5 times and then goes off and the up and down buttons are then unable to raise the power

the battery status stays powered and doesn’t change

Can you check error codes on this system with no display ?

View attachment 107592

That has to be really frustrating. Ive not seen that particular display on the many bafangs i´ve
looked at; what bike have you? It looks like a very cheap display. Since your battery & connects
seem fine it may be in the display. Moisture can get into a display & reek havoc. Then too, the
cold could possibly have cracked a fragile connect either in the display or battery circuit board?
Did you see any sign of bleed or corrosion on the controller? Error codes can be searched online;
many are model specific. Pretty obvious the display can´t post an error code, but you might check
for codes & troubleshoot online, Sry I can´t be of more help.

 

[tomjasz]

I assume that connection is okay too

I'd not assume anything. When you say, "in and out a few times" are you referring to removing the battery case from it's base mount? If yes please check that connection. Some battery bases have slots that can be problematic and not have a solid connection.