bought used bike with bbso2 installed -now it won't work

[Juli]

I took the bike to a shop that specializes in EBikes and sells Bafang kits. He said the controller was bad. Now I have to decide whether to get my money back or have the seller put another controller on the unit. He would switch out the one on his other bike.

[Juli]

Thanks, I tried that. Still didn't work

[Juli]

Put charger on, fan turned off, seller said that meant fully charged, also display said fully charged.
Display works just fine

[spinningmagnets]

Perhaps disconnect the E-brakes, and then try again to se if the brake signal is "ON" all the time?

[Eric Luna]

How do you know its fully charged? Can you pick up the rear tire and give it throttle does the system still cut out?

Does the display stay lit after it jerks and dies?

[Juli]

Hi,
I hope someone can help me figure this out. I bought a used bike with a Bafang BBS02 installed. It worked fine when I picked it up but I went to ride it 3 days later and now it doesn't work. Display works, says battery is fully charged but when I hit the throttle it just gives a small jerk and then nothing. Could it be a bad controller? it does the same thing in peddle assist, I peddle it gives a small jerk and no motor. I didn't do anything to the bike from first buying it to trying to ride it 3 days later. it wasn't dropped or left out in the rain. Just sat under a tarp in our shop. Guy claims he just installed the unit last year and only used it sparingly. He has another ebike (also BBS02) that he uses and this one was built in case someone else wanted to ride with him.