BBS02 750w only drawing 7.5 amps max

[iheartsteeltubes]

I need some guidance on how to go about fixing my ebike. I have a year old 48v BBS02 750w mid drive with 1800 miles on it. 48v 20ah battery. I recently had a problem where it will only draw 7.5 amps max not matter what setting its on. It will still spin up to the RPM of whatever power level its on, but itll only use 7.5 amps to get there.

Everything else is functioning normally. I took the battery apart and checked all the inner connections. I replaced the connectors for the battery and motor. I took the motor apart and inspected it, everything is normal. No signs of water getting in and the motor still spins how it should. The connectors on the controller show no signs or corrosion or being burnt. Ive unplugged/plugged every connector. The motor is not overheating.

I even took the display apart and it looked brand new inside, no signs of water getting in. No burnt connections. Ive tried running it with the brake cutoff sensors and throttle disconnected and no change.

The first time it started doing this I pulled over and plugged/unplugged everything trying to get it to work. I dont think it helped. So I continued riding, down on power and all of a sudden it started working properly again. That lasted about 6 miles before it became limited again.

Ive been googleing the last 2 days trying to find an answer but cant. I havent seen anyone post about having this same problem either.

Does anyone have any ideas? Its behaving almost as if theres a setting limiting it to 7.5 amps, but there shouldnt be.

 

[HumanPerson]

Could be the controller, it could be something in the display as well.

I'd think it'd be in the controller, something getting ready to go completely..make sense?

Where'd you get the BBS02 from?
No water ingress from riding through water puddles?

What was going on before this started to happen? Weather? Topography?

So many more questions to ask perhaps others will chime in soon

Welcome to the forums by the way

 

[iheartsteeltubes]

Could be the controller, it could be something in the display as well.

I'd think it'd be in the controller, something getting ready to go completely..make sense?

Where'd you get the BBS02 from?
No water ingress from riding through water puddles?

What was going on before this started to happen? Weather? Topography?

So many more questions to ask perhaps others will chime in soon

Welcome to the forums by the way

I bought it on eBay from the seller "mossen" almost exactly a year ago. 7/24/22
It started happening about a mile into a ride on a clear day on somewhat flatish ground. I had it on level 5 of 9 and was pedalling. Peak draw was maybe 700w until then.

I havent rode through any puddles but I have rode it on rainy days. Its my main source of transportation so I dont really have a choice there. Thats why I assumed water getting in could have damaged something, but taking it apart I didnt see any evidence of water getting in. When I first got it I added silicone sealant on the outside of all the seams to try and prevent that from happening.

I guess it still could have, just not enough for me to see it. But enough to mess with the computer.

I live in the mountains so I go up hills constantly. Like the most extreme one rises about 500ft over a mile or something close to that. Constant switchbacks, Im either going uphill or coasting down. Not much flat ground near me.
But Ive always been careful to keep it in a low gear and pedal when going uphill. 99% of the time its on level 5 of 9 and Im pedaling. I dont just leave it on the highest setting and bog down the motor. For the most part its either drawing 600-1000w, or Im coasting down hill.

Do controllers usually go bad after only 1800 miles? I got a mid drive because I thought it would last longer since Im around so many hills, but for the price of a new controller I can almost get a new direct drive hub motor.

Whats throwing me off is that its functioning perfectly otherwise. The power isnt choppy, its not overheating. No weird noises. Its like theres just a limiter keeping it at 7.5 amps.

Heres what my commute looks like:

 

[ElHegpah]

A "menu setting" does not go in and out. Your problem is variable. Not a setting, either a connection or component problem.

Yes, BBS series controllers do go bad, fairly common, they are inside the motor and subjected to more heat. If you do replace, VERY CAREFULLY check the part number on the actual controller itself. Bafang frequently change these controllers on the same model motor, often with no notice to dealers, and they are NOT intechangeable, usually. Make SURE you get the matching replacement. UNLESS - they have a Compatible replacement that offers some improvements, but double check it will be plug and play with what you have now. Verify this with something other than the salesman's say so.